CA2540104A1 - Water soluble nanoparticles comprising inclusion complexes - Google Patents
Water soluble nanoparticles comprising inclusion complexes Download PDFInfo
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- CA2540104A1 CA2540104A1 CA002540104A CA2540104A CA2540104A1 CA 2540104 A1 CA2540104 A1 CA 2540104A1 CA 002540104 A CA002540104 A CA 002540104A CA 2540104 A CA2540104 A CA 2540104A CA 2540104 A1 CA2540104 A1 CA 2540104A1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y5/00—Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
- A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
- A61K47/69—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit
- A61K47/6921—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere
- A61K47/6927—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a solid microparticle having no hollow or gas-filled cores
- A61K47/6929—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a solid microparticle having no hollow or gas-filled cores the form being a nanoparticle, e.g. an immuno-nanoparticle
- A61K47/6931—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a solid microparticle having no hollow or gas-filled cores the form being a nanoparticle, e.g. an immuno-nanoparticle the material constituting the nanoparticle being a polymer
- A61K47/6933—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a solid microparticle having no hollow or gas-filled cores the form being a nanoparticle, e.g. an immuno-nanoparticle the material constituting the nanoparticle being a polymer the polymer being obtained by reactions only involving carbon to carbon, e.g. poly(meth)acrylate, polystyrene, polyvinylpyrrolidone or polyvinylalcohol
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
- A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
- A61K47/69—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit
- A61K47/6921—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere
- A61K47/6927—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a solid microparticle having no hollow or gas-filled cores
- A61K47/6929—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a solid microparticle having no hollow or gas-filled cores the form being a nanoparticle, e.g. an immuno-nanoparticle
- A61K47/6931—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a solid microparticle having no hollow or gas-filled cores the form being a nanoparticle, e.g. an immuno-nanoparticle the material constituting the nanoparticle being a polymer
- A61K47/6939—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a solid microparticle having no hollow or gas-filled cores the form being a nanoparticle, e.g. an immuno-nanoparticle the material constituting the nanoparticle being a polymer the polymer being a polysaccharide, e.g. starch, chitosan, chitin, cellulose or pectin
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
- A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
- A61K47/69—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit
- A61K47/6949—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit inclusion complexes, e.g. clathrates, cavitates or fullerenes
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P25/00—Drugs for disorders of the nervous system
- A61P25/28—Drugs for disorders of the nervous system for treating neurodegenerative disorders of the central nervous system, e.g. nootropic agents, cognition enhancers, drugs for treating Alzheimer's disease or other forms of dementia
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
- A61P31/04—Antibacterial agents
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
- A61P31/10—Antimycotics
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P35/00—Antineoplastic agents
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P5/00—Drugs for disorders of the endocrine system
- A61P5/24—Drugs for disorders of the endocrine system of the sex hormones
- A61P5/32—Antioestrogens
Abstract
Nano-dispersions of water-soluble and stable nano-sized particlesare provided comprising hydrophilic inclusion complexes of an active compound in a non-crystalline state surrounded by and entrapped within an amphiphilic polymer.
The inclusion complex is stabilized by non-valent interactions between the active compound and the polymer. The following pairs of active compound/amphiphilic polymers are provided: (i) azithromycin/ a polysaccharide or polyvinyl alcohol, or clarithromycin/alginate or chitosan; (ii) donepezil hydrochloride/ a polysaccharide; (iii) an azole compound/a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid; and (iv) a taxane/gelatin.
The inclusion complex is stabilized by non-valent interactions between the active compound and the polymer. The following pairs of active compound/amphiphilic polymers are provided: (i) azithromycin/ a polysaccharide or polyvinyl alcohol, or clarithromycin/alginate or chitosan; (ii) donepezil hydrochloride/ a polysaccharide; (iii) an azole compound/a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid; and (iv) a taxane/gelatin.
Description
WATER SOLUBLE NANOPARTICLES AND METHOD
FOR THEIR PRODUCTION
FIELD OF THE INVENTION
The present invention is in the field of nanoparticles. More particularly, the invention relates to nano-dispersions of water-soluble and stable nano-sized particles consisting of inclusion complexes of active compounds such as pharmaceutical drugs or pesticides surrounded by and entrapped within suitable amphiphilic polymers, and methods of producing said nano-dispersions.
BACKGROUND OF THE INVENTION
Two formidable barriers to effective drug delivery and hence to disease treatment, are solubility and stability. To be absorbed in the human body, a compound has to be soluble in both water and fats (lipids). Solubility in water is, however, often associated with poor fat solubility and vice-versa.
Over one third of drugs listed in the U. S. Pharmacopoeia and about 50% of new chemical entities (NCEs) are insoluble or poorly insoluble in water. Over 40%
of drug molecules and drug compounds are insoluble in the human body. In spite of this, lipophilic drug substances having low water solubility are a growing drug class having increasing applicability in a variety of therapeutic areas and for a variety of pathologies. There are over 2500 large molecules in various stages of development today, and over 5500 small molecules in development (See Drug Delivery Companies Report 2001, p.2, www.pharmaventures.com). Each of the existing companies focusing on these large and small molecules has its own restriction and limitations with regard to both large and small molecules on which they focus.
Solubility and stability issues are major formulation obstacles hindering the development of therapeutic agents. Aqueous solubility is a necessary but frequently elusive property for formulations of the complex organic structures found in pharmaceuticals. Traditional formulation systems for very insoluble drugs have involved a combination of organic solvents, surfactants and extreme pH
conditions.
These formulations are often irritating to the patient and may cause adverse reactions. At times, these methods are inadequate for solubilizing enough of a quantity of a drug for a parenteral formulation. In such cases, doctors may administer an "overdosage", such as for example with poorly soluble vitamins.
In most cases, this overdosage does not cause any harm since the unabsorbed quantities exit the body with urine. Overdosage does, however, waste a large amount of the active compound.
The size of the drug molecules also plays a major role in their solubility and stability as well as bioavailability. Bioavailability refers to the degree to which a drug becomes available to the target tissue or any alternative in vivo target (i. e., receptors, tumors, etc.) after being administered to the body. Poor bioavailability is a significant problem encountered in the development of pharmaceutical compositions, particularly those containing an active ingredient that is poorly soluble in water. Poorly water-soluble drugs tend to be eliminated from the gastrointestinal tract before being absorbed into the circulation. It is known that the rate of dissolution of a particulate drug can increase with increasing surface area, that is, decreasing particle size Recently, there has been an explosion of interest in nanotechnology, the manipulation on the nanoscale. Nanotechnology is not an entirely new field:
colloidal sols and supported platinum catalysts are nanoparticles.
Nevertheless, the recent interest in the nanoscale has produced, among numerous other things, materials used for and in drug delivery. Nanoparticles are generally considered to be solids whose diameter varies between 1-1000 nm.
Although a number of solubilization technologies do exist, such as liposomes, cylcodextrins, microencapuslation, and dendrimers, each of these technologies has a number of significant disadvantages.
Phospholipids exposed to aqueous environment form a bi-layer structure called liposomes. Liposomes are microscopic spherical structures composed of phospholipids that were first discovered in the early 1960s. In aqueous media, phospholipid molecules, being amphiphilic, spontaneously organize themselves in self closed bilayers as a result of hydrophilic and hydrophobic interactions.
The resulting vesicles, referred to as liposomes, therefore encapsulate in the interior part of the aqueous medium in which they are suspended, a property that makes them potential carriers for biologically active hydrophilic molecules and drugs in vivo.
Lipophilic agents may also be transported, embedded in the liposomal membrane.
Liposomes resemble the bio-membranes and have been used for many years as a tool for solubilization of biological active molecules insoluble in water.
They are non-toxic and biodegradable and can be used for specific target organs.
Liposome technology allows for the preparation of smaller to larger vesicles, using unilamellar (ULV) and multilamellar (MLV) vesicles. MLVs are produced by mechanical agitation. Large ULVs are prepared from MLV by extrusion under pressure through membranes of known pore size. The sizes are usually 200 nm or less in diameter; however, liposomes can be custom designed for almost any need by varying lipid content, surface change and method of preparation.
As drug carriers, liposomes have several potential advantages, including the ability to carry a significant amount of drug, relative ease of preparation, and low toxicity if natural lipids are used. However, common problems encountered with liposomes include: low stability, short shelf life, poor tissue specificity, and toxicity with non-native lipids. Additionally, the uptake by phagocytic cells reduces circulation times. Furthermore, preparing liposome formulations that exhibit narrow size distribution has been a formidable challenge under demanding conditions, as well as a costly one. Also, membrane clogging often results during the production of larger volumes required for pharmaceutical production of a particular drug.
Cyclodextrins are crystalline, water-soluble, cyclic, non-reducing oligo-saccharides built from six, seven, or eight glucopyranose units, referred to as alpha, beta and gamma cyclodextrin, respectively, which have long been known as products that are capable of forming inclusion complexes. The cyclodextrin structure provides a molecule shaped like a segment of a hollow cone with an exterior hydrophilic surface and interior hydrophobic cavity.
The hydrophilic surface generates good water solubility for the cyclodextrin and the hydrophobic cavity provides a favorable environment in which to enclose, envelope or entrap the drug molecule. This association isolates the drug from the aqueous solvent and may increase the drug's water solubility and stability.
For a long time most cyclodextrins had been no more than scientific curiosities due to their limited availability and high price.
As a result of intensive research and advances in enzyme technology, cyclodextrins and their chemically modified derivatives are now available commercially, generating a new technology: packing on the molecular level.
Cyclodextrins are, however, fraught with disadvantages. An ideal cyclodextrin would exhibit both oral and systemic safety. It would have water solubility greater than the parent cyclodextrins yet retain or surpass their complexation characteristics. The disadvantages of the cyclodextrins, however, include:
limited space available for the active molecule to be entrapped inside the core, lack of pure stability of the complex, limited availability in the marketplace, and high price.
Microencapsulation is a process by which tiny parcels of a gas, liquid, or solid active ingredient (also referred to herein and used interchangeably with "core material") are packaged within a second material for the purpose of shielding the active ingredient from the surrounding environment. These capsules, which range in size from one micron (one-thousandth of a millimeter) to approximately seven millimeters, release their contents at a later time by means appropriate to the application.
There are four typical mechanisms by which the core material is released from a microcapsule: (1) mechanical rupture of the capsule wall, (2) dissolution of the wall, (3) melting of the wall, and (4) diffusion through the wall. Less common release mechanisms include ablation (slow erosion of the shell) and biodegradation.
Microencapsulation covers several technologies, where a certain material is coated to obtain a micro-package of the active compound. The coating is performed to stabilize the material, for taste masking, preparing free flowing material of otherwise clogging agents etc. and many other purposes. This technology has been successfully applied in the feed additive industry and to agriculture. The relatively high production cost needed for many of the formulations is, however, a significant disadvantage.
In the cases of nanoencapsulation and nanoparticles (which are advantageously shaped as spheres and, hence, nanospheres), two types of systems having different inner structures are possible: (i) a matrix-type system composed of an entanglement of oligomer or polymer units, defined as nanoparticles or nanospheres, and (ii) a reservoir-type system, consisting of an oily core surrounded by a polymer wall, defined as a nanocapsule.
Depending upon the nature of the materials used to prepare the nanospheres, the following classification exists: (a) amphiphilic macromolecules that undergo a cross-linking reaction during preparation of the nanospheres; (b) monomers that polymerize during preparation of the nanoparticles; and (c) hydrophobic polymers, which are initially dissolved in organic solvents and then precipitated under controlled conditions to produce nanoparticles.
Problems associated with the use of polymers in micro- and nanoencapsulation include: the use of toxic emulgators in emulsions or dispersions, polymerization or the application of high shear forces during emulsification process, insufficient biocompatibility and biodegrability, balance of hydrophilic and hydrophobic moieties, etc. These characteristics lead to insufficient drug release.
Dendrimers are a class of polymers distinguished by their highly branched, tree-like structures. They are synthesized in an iterative fashion from ABn monomers, with each iteration adding a layer or "generation" to the growing polymer. Dendrimers of up to ten generations have been synthesized with molecular weights in excess of 106 kDa. One important feature of dendrimeric polymers is their narrow molecular weight distributions. Indeed, depending on the synthetic strategy used, dendrimers with molecular weights in excess of 20 kDa can be made as single compounds.
FOR THEIR PRODUCTION
FIELD OF THE INVENTION
The present invention is in the field of nanoparticles. More particularly, the invention relates to nano-dispersions of water-soluble and stable nano-sized particles consisting of inclusion complexes of active compounds such as pharmaceutical drugs or pesticides surrounded by and entrapped within suitable amphiphilic polymers, and methods of producing said nano-dispersions.
BACKGROUND OF THE INVENTION
Two formidable barriers to effective drug delivery and hence to disease treatment, are solubility and stability. To be absorbed in the human body, a compound has to be soluble in both water and fats (lipids). Solubility in water is, however, often associated with poor fat solubility and vice-versa.
Over one third of drugs listed in the U. S. Pharmacopoeia and about 50% of new chemical entities (NCEs) are insoluble or poorly insoluble in water. Over 40%
of drug molecules and drug compounds are insoluble in the human body. In spite of this, lipophilic drug substances having low water solubility are a growing drug class having increasing applicability in a variety of therapeutic areas and for a variety of pathologies. There are over 2500 large molecules in various stages of development today, and over 5500 small molecules in development (See Drug Delivery Companies Report 2001, p.2, www.pharmaventures.com). Each of the existing companies focusing on these large and small molecules has its own restriction and limitations with regard to both large and small molecules on which they focus.
Solubility and stability issues are major formulation obstacles hindering the development of therapeutic agents. Aqueous solubility is a necessary but frequently elusive property for formulations of the complex organic structures found in pharmaceuticals. Traditional formulation systems for very insoluble drugs have involved a combination of organic solvents, surfactants and extreme pH
conditions.
These formulations are often irritating to the patient and may cause adverse reactions. At times, these methods are inadequate for solubilizing enough of a quantity of a drug for a parenteral formulation. In such cases, doctors may administer an "overdosage", such as for example with poorly soluble vitamins.
In most cases, this overdosage does not cause any harm since the unabsorbed quantities exit the body with urine. Overdosage does, however, waste a large amount of the active compound.
The size of the drug molecules also plays a major role in their solubility and stability as well as bioavailability. Bioavailability refers to the degree to which a drug becomes available to the target tissue or any alternative in vivo target (i. e., receptors, tumors, etc.) after being administered to the body. Poor bioavailability is a significant problem encountered in the development of pharmaceutical compositions, particularly those containing an active ingredient that is poorly soluble in water. Poorly water-soluble drugs tend to be eliminated from the gastrointestinal tract before being absorbed into the circulation. It is known that the rate of dissolution of a particulate drug can increase with increasing surface area, that is, decreasing particle size Recently, there has been an explosion of interest in nanotechnology, the manipulation on the nanoscale. Nanotechnology is not an entirely new field:
colloidal sols and supported platinum catalysts are nanoparticles.
Nevertheless, the recent interest in the nanoscale has produced, among numerous other things, materials used for and in drug delivery. Nanoparticles are generally considered to be solids whose diameter varies between 1-1000 nm.
Although a number of solubilization technologies do exist, such as liposomes, cylcodextrins, microencapuslation, and dendrimers, each of these technologies has a number of significant disadvantages.
Phospholipids exposed to aqueous environment form a bi-layer structure called liposomes. Liposomes are microscopic spherical structures composed of phospholipids that were first discovered in the early 1960s. In aqueous media, phospholipid molecules, being amphiphilic, spontaneously organize themselves in self closed bilayers as a result of hydrophilic and hydrophobic interactions.
The resulting vesicles, referred to as liposomes, therefore encapsulate in the interior part of the aqueous medium in which they are suspended, a property that makes them potential carriers for biologically active hydrophilic molecules and drugs in vivo.
Lipophilic agents may also be transported, embedded in the liposomal membrane.
Liposomes resemble the bio-membranes and have been used for many years as a tool for solubilization of biological active molecules insoluble in water.
They are non-toxic and biodegradable and can be used for specific target organs.
Liposome technology allows for the preparation of smaller to larger vesicles, using unilamellar (ULV) and multilamellar (MLV) vesicles. MLVs are produced by mechanical agitation. Large ULVs are prepared from MLV by extrusion under pressure through membranes of known pore size. The sizes are usually 200 nm or less in diameter; however, liposomes can be custom designed for almost any need by varying lipid content, surface change and method of preparation.
As drug carriers, liposomes have several potential advantages, including the ability to carry a significant amount of drug, relative ease of preparation, and low toxicity if natural lipids are used. However, common problems encountered with liposomes include: low stability, short shelf life, poor tissue specificity, and toxicity with non-native lipids. Additionally, the uptake by phagocytic cells reduces circulation times. Furthermore, preparing liposome formulations that exhibit narrow size distribution has been a formidable challenge under demanding conditions, as well as a costly one. Also, membrane clogging often results during the production of larger volumes required for pharmaceutical production of a particular drug.
Cyclodextrins are crystalline, water-soluble, cyclic, non-reducing oligo-saccharides built from six, seven, or eight glucopyranose units, referred to as alpha, beta and gamma cyclodextrin, respectively, which have long been known as products that are capable of forming inclusion complexes. The cyclodextrin structure provides a molecule shaped like a segment of a hollow cone with an exterior hydrophilic surface and interior hydrophobic cavity.
The hydrophilic surface generates good water solubility for the cyclodextrin and the hydrophobic cavity provides a favorable environment in which to enclose, envelope or entrap the drug molecule. This association isolates the drug from the aqueous solvent and may increase the drug's water solubility and stability.
For a long time most cyclodextrins had been no more than scientific curiosities due to their limited availability and high price.
As a result of intensive research and advances in enzyme technology, cyclodextrins and their chemically modified derivatives are now available commercially, generating a new technology: packing on the molecular level.
Cyclodextrins are, however, fraught with disadvantages. An ideal cyclodextrin would exhibit both oral and systemic safety. It would have water solubility greater than the parent cyclodextrins yet retain or surpass their complexation characteristics. The disadvantages of the cyclodextrins, however, include:
limited space available for the active molecule to be entrapped inside the core, lack of pure stability of the complex, limited availability in the marketplace, and high price.
Microencapsulation is a process by which tiny parcels of a gas, liquid, or solid active ingredient (also referred to herein and used interchangeably with "core material") are packaged within a second material for the purpose of shielding the active ingredient from the surrounding environment. These capsules, which range in size from one micron (one-thousandth of a millimeter) to approximately seven millimeters, release their contents at a later time by means appropriate to the application.
There are four typical mechanisms by which the core material is released from a microcapsule: (1) mechanical rupture of the capsule wall, (2) dissolution of the wall, (3) melting of the wall, and (4) diffusion through the wall. Less common release mechanisms include ablation (slow erosion of the shell) and biodegradation.
Microencapsulation covers several technologies, where a certain material is coated to obtain a micro-package of the active compound. The coating is performed to stabilize the material, for taste masking, preparing free flowing material of otherwise clogging agents etc. and many other purposes. This technology has been successfully applied in the feed additive industry and to agriculture. The relatively high production cost needed for many of the formulations is, however, a significant disadvantage.
In the cases of nanoencapsulation and nanoparticles (which are advantageously shaped as spheres and, hence, nanospheres), two types of systems having different inner structures are possible: (i) a matrix-type system composed of an entanglement of oligomer or polymer units, defined as nanoparticles or nanospheres, and (ii) a reservoir-type system, consisting of an oily core surrounded by a polymer wall, defined as a nanocapsule.
Depending upon the nature of the materials used to prepare the nanospheres, the following classification exists: (a) amphiphilic macromolecules that undergo a cross-linking reaction during preparation of the nanospheres; (b) monomers that polymerize during preparation of the nanoparticles; and (c) hydrophobic polymers, which are initially dissolved in organic solvents and then precipitated under controlled conditions to produce nanoparticles.
Problems associated with the use of polymers in micro- and nanoencapsulation include: the use of toxic emulgators in emulsions or dispersions, polymerization or the application of high shear forces during emulsification process, insufficient biocompatibility and biodegrability, balance of hydrophilic and hydrophobic moieties, etc. These characteristics lead to insufficient drug release.
Dendrimers are a class of polymers distinguished by their highly branched, tree-like structures. They are synthesized in an iterative fashion from ABn monomers, with each iteration adding a layer or "generation" to the growing polymer. Dendrimers of up to ten generations have been synthesized with molecular weights in excess of 106 kDa. One important feature of dendrimeric polymers is their narrow molecular weight distributions. Indeed, depending on the synthetic strategy used, dendrimers with molecular weights in excess of 20 kDa can be made as single compounds.
Dendrimers, like liposomes, display the property of encapsulation, and are able to sequester molecules within the interior spaces. Because they are single molecules, not assemblies, drug-dendrimer complexes are expected to be significantly more stable than liposomal drugs. Dendrimers are thus considered as one of the most promising vehicles for drug delivery systems. However, the dendrimer technology is still in the research stage, and it is speculated that it will take years before it is applied in the industry as a safe and efficient drug delivery system.
What is needed is a safe, biocompatible, stable and efficient drug delivery system that comprises nano-sized particles of an active ingredient for enhanced bioavailability and which overcomes the problems inherent in the prior art.
US Patent Application Publication No. US 2003/0129239 assigned to the present applicant discloses the general technology for the preparation of nano-particles according to the present invention.
SUMMARY OF THE INVENTION
Lipophilic and hydrophilic compounds that are solubilized in the form of nano-sized particles, or "nanoparticles", can be used in pharmacology, in the production of food additives, cosmetics, and agriculture, as well as in pet foods and veterinary products, amongst other uses.
The present invention provides nano-dispersions of nano-particles and methods for the production of soluble nano-particles and, in particular, inclusion complexes of water-insoluble lipophilic and water-soluble hydrophilic organic materials.
An inclusion complex, by definition, is a complex in which one component, designated "the host", forms a cavity in which molecular entities of a second chemical species, designated "the guest", are located. Thus, in accordance with the present invention, it can be defined that the solu-nanoparticles comprise inclusion complexes in which the host is the amphiphilic polymer or group of polymers and the guest is the active compound molecules wrapped and fixated or secured within the cavity or space formed by said polymer host.
In accordance with the present invention, the inclusion complexes contain the active compound molecules, which interact with the polymer by non-valent interactions and form a polymer-active compound as a distinct molecular entity. A
significant advantage and unique feature of the inclusion complex of the present invention is that no new chemical bonds axe formed and no existing bonds are destroyed during the formation of the inclusion complex. The particles comprising the inclusion complexes are nano-level in size, and no change occurs in the drug molecule itself when it is enveloped, or advantageously wrapped, by the polymer.
The outer surface of the inclusion complexes is comprised of a polymer that carries the active compound, when it is a drug molecule, to the target destination.
Depending upon the polymer used in the formation of the nano-particles, the drugs and pharmaceuticals within the complex are able to reach specific areas of the body readily and quickly. The polymer and active compound selected will also provide nano-particles capable of mufti-level, mufti-stage and/or controlled release of the drug or pharmaceutical within the body.
The nano-particles of the invention remain stable for long periods of time, may be manufactured at a low cost, and may improve the overall bioavailability of the active compound.
In particular, the present invention provides nano-dispersions of water-soluble and stable nano-sized particles comprising hydrophilic inclusion complexes consisting essentially of an active compound surrounded by and entrapped within an amphiphilic polymer, wherein said active compound is in a non-crystalline state and said inclusion complex is stabilized by non-valent interactions between the active compound and the surrounding amphiphilic polymer, and wherein said inclusion complex is selected from the group consisting of:
(i) an inclusion complex wherein the active compound is clarithromycin and the amphiphilic polymer is alginate or chitosan or the active compound is azithromycin and the amphiphilic polymer is a polysaccharide or polyvinyl alcohol;
(i) an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide;
(iii) an inclusion complex wherein the active compound is an azole fungicide and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid; and (iv) an inclusion complex wherein the active compound is a taxane and the amphiphilic polymer is gelatin.
The present invention also provides pharmaceutical compositions comprising the stable nano-dispersions of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 illustrates the size distribution of nano-particles comprising clarithromycin-chitosan inclusion complexes (#10-134, Table 3) having a size of approximately 838 nm, as measured by light diffraction (ALV).
Fig. 2 illustrates the in vitro release via a dialysis membrane of commercial clarithromycin (Clari) in comparison with particles comprising clarithromycin inclusion complexes with PVA (S-Clari#-34, Table 3) or nano-particles comprising clarithromycin inclusion complexes with chitosan (S-Clari#135, Table 3).
Fig. 3 illustrates the size distribution of nano-particles comprising azithromycin-chitosan inclusion complexes (#10-148/2, Table 4) having a size of approximately 362 nm, as measured by light diffraction (ALV).
Fig. 4 illustrates X-ray spectra of 10-month old azithromycin-chitosan inclusion complex sample (bottom trace) compared to the commercially available azithromycin (upper trace).
Fig. 5 illustrates the size distribution of nano-particles comprising itraconazole-modified starch inclusion complexes (#23-120, Table S) having a size of approximately 414 nm, as measured by light diffraction (ALV).
What is needed is a safe, biocompatible, stable and efficient drug delivery system that comprises nano-sized particles of an active ingredient for enhanced bioavailability and which overcomes the problems inherent in the prior art.
US Patent Application Publication No. US 2003/0129239 assigned to the present applicant discloses the general technology for the preparation of nano-particles according to the present invention.
SUMMARY OF THE INVENTION
Lipophilic and hydrophilic compounds that are solubilized in the form of nano-sized particles, or "nanoparticles", can be used in pharmacology, in the production of food additives, cosmetics, and agriculture, as well as in pet foods and veterinary products, amongst other uses.
The present invention provides nano-dispersions of nano-particles and methods for the production of soluble nano-particles and, in particular, inclusion complexes of water-insoluble lipophilic and water-soluble hydrophilic organic materials.
An inclusion complex, by definition, is a complex in which one component, designated "the host", forms a cavity in which molecular entities of a second chemical species, designated "the guest", are located. Thus, in accordance with the present invention, it can be defined that the solu-nanoparticles comprise inclusion complexes in which the host is the amphiphilic polymer or group of polymers and the guest is the active compound molecules wrapped and fixated or secured within the cavity or space formed by said polymer host.
In accordance with the present invention, the inclusion complexes contain the active compound molecules, which interact with the polymer by non-valent interactions and form a polymer-active compound as a distinct molecular entity. A
significant advantage and unique feature of the inclusion complex of the present invention is that no new chemical bonds axe formed and no existing bonds are destroyed during the formation of the inclusion complex. The particles comprising the inclusion complexes are nano-level in size, and no change occurs in the drug molecule itself when it is enveloped, or advantageously wrapped, by the polymer.
The outer surface of the inclusion complexes is comprised of a polymer that carries the active compound, when it is a drug molecule, to the target destination.
Depending upon the polymer used in the formation of the nano-particles, the drugs and pharmaceuticals within the complex are able to reach specific areas of the body readily and quickly. The polymer and active compound selected will also provide nano-particles capable of mufti-level, mufti-stage and/or controlled release of the drug or pharmaceutical within the body.
The nano-particles of the invention remain stable for long periods of time, may be manufactured at a low cost, and may improve the overall bioavailability of the active compound.
In particular, the present invention provides nano-dispersions of water-soluble and stable nano-sized particles comprising hydrophilic inclusion complexes consisting essentially of an active compound surrounded by and entrapped within an amphiphilic polymer, wherein said active compound is in a non-crystalline state and said inclusion complex is stabilized by non-valent interactions between the active compound and the surrounding amphiphilic polymer, and wherein said inclusion complex is selected from the group consisting of:
(i) an inclusion complex wherein the active compound is clarithromycin and the amphiphilic polymer is alginate or chitosan or the active compound is azithromycin and the amphiphilic polymer is a polysaccharide or polyvinyl alcohol;
(i) an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide;
(iii) an inclusion complex wherein the active compound is an azole fungicide and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid; and (iv) an inclusion complex wherein the active compound is a taxane and the amphiphilic polymer is gelatin.
The present invention also provides pharmaceutical compositions comprising the stable nano-dispersions of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 illustrates the size distribution of nano-particles comprising clarithromycin-chitosan inclusion complexes (#10-134, Table 3) having a size of approximately 838 nm, as measured by light diffraction (ALV).
Fig. 2 illustrates the in vitro release via a dialysis membrane of commercial clarithromycin (Clari) in comparison with particles comprising clarithromycin inclusion complexes with PVA (S-Clari#-34, Table 3) or nano-particles comprising clarithromycin inclusion complexes with chitosan (S-Clari#135, Table 3).
Fig. 3 illustrates the size distribution of nano-particles comprising azithromycin-chitosan inclusion complexes (#10-148/2, Table 4) having a size of approximately 362 nm, as measured by light diffraction (ALV).
Fig. 4 illustrates X-ray spectra of 10-month old azithromycin-chitosan inclusion complex sample (bottom trace) compared to the commercially available azithromycin (upper trace).
Fig. 5 illustrates the size distribution of nano-particles comprising itraconazole-modified starch inclusion complexes (#23-120, Table S) having a size of approximately 414 nm, as measured by light diffraction (ALV).
Figs. 6A-6B illustrates differential scanning calorimetry (DSC) analysis of commercial crystalline itraconazole ( 12A) and of nano-particles comprising itraconazole-polyacrylic acid inclusion complexes (#IT-56, Table 5).
Fig. 7 illustrates the size distribution of nano-particles comprising paclitaxel-gelatin inclusion complexes (# 25-85, Table 6) having a size of approximately nm, as measured by light diffraction (ALV).
Fig. 8 illustrates the size distribution of nano-particles comprising donepezil-modified starch inclusion complexes (#LG-7-51, Table 7) having a size of approximately 600 nm, as measured by light diffraction (ALV) Fig. 9 illustrates oral absorption of the following materials in a preclinical model involving rats: commercial formulation of azithromycin (Azenil), fluid formulations of nano-particles of azithromycin-chitosan inclusion complexes (from lots 28-39 and 28-59) and of lot 28-59 that were further formulated in tablet form.
DETAILED DESCRIPTION OF THE INVENTION
The nanoparticles of the present invention comprise the insoluble or soluble active compound or core, wrapped within a water-soluble amphiphilic polymer. A
variety of different polymers can be used according to the present invention for any of the selected active compound, that can be lipophilic or hydrophilic. The polymer, or groups of polymers, is selected according to an algorithm that takes into account various physical properties of both the active lipophilic or hydrophilic compound and the interaction of this compound within the resulting active compound /polymer nano-particle. This technology is fully described in the above-referenced US
2003/0129239.
One important parameter in the choice of the polymer or polymers is the HLB, i.e., the measure of the molecular balance of the hydrophilic and lipophilic portions of the compound. Within the HLB International Scale of 0-20, lipophilic molecules have a HLB of less than 6, and hydrophilic molecules have a HLB of more than 6. Thus, according to the present invention, the HLB of the polymer is selected in such a way that, after combining to it the active compound, the total resulting HLB value of the complex will be greater than 8, rendering the complex water-soluble.
As used herein, the term "non-crystalline" refers to materials both in amorphous or disordered crystalline state. In preferred embodiments, the material is amorphous. It is known by those skilled in the art that the amorphous state is preferred for drug delivery as it may indeed enhance bioavailability.
As used herein, the terms "water-soluble nano-particles", "aqueous solution of nano-particles" and "nano-dispersion" are used interchangeably and both intend to refer to the same thing, namely, to a fme dispersion of the nano-particles that may have the appearance of a solution, but is not a classical aqueous solution.
As used herein, the terms "stable nano-dispersion" and "nano-dispersion of water-soluble and stable nano-sized particles" are used interchangeably and both intend to refer to the same thing, namely, to a stable fine dispersion of the nano-particles.
Stability of the nano-particles and of the inclusion complexes has more than one meaning. The nano-particles should be stable as part of a nanocomplex over time, while remaining in the dispersion media. The nano-dispersions are stable over time without separation of phases. Furthermore, the amorphous state should be also retained over time.
It is worth noting that in the process used in the present invention, the components of the system do not result in micelles nor do they form classical dispersion systems. The technology of the present invention causes the following:
(i) after forming the inclusion complex, the poorly soluble or insoluble (or even non-wettable) active compound becomes pseudo-soluble. When the particle size is about 20-30 nm, then the material becomes soluble and visually transparent, rather than opaque;
(ii) after dispersion of the active compound to nano-size and fixation by the polymers to form an inclusion complex, enhanced solubility in physiological fluids, in vivo, improved absorption, and improved biological activity, as well as transmission to a stable non-crystalline, preferably amorphous, state, are achieved ;
(iii) a crystalline biologically-active compound becomes amorphous and thus exhibits improved biological activity.
In most preferred embodiments of the present invention, not less than 80% of the nano-particles in the nano-dispersion are within the size range, when the size deviation is not greater than 20%, and the particle size is within the nano range, namely less than 1000 nm.
In an advantageous and preferred embodiment of the invention, the polymer molecule in the polymer solution "wraps" the active compound via non-valent interactions. As used herein, the term "non-valent" is intended to refer to non-covalent, non-ionic and non-semi-polaric bonds and/or interactions, and includes, for example, electrostatic forces, Van der Waals forces, and hydrogen-bonds between the polymer and the active compound in the inclusion complex such that the non-valent interactions fixate the active compound within the polymer which thus reduces the molecular flexibility of the active compound and polymer. The formation of any valent bonds could change the characteristics or properties of the active compound. The formation of non-valent bonds preserves the structure and properties of the lipophilic compound, which is particularly important when the active compound is a pharmaceutical. _ The present invention provides a nano-dispersion of water-soluble and stable nano-sized particles comprising hydrophilic inclusion complexes consisting essentially of an active compound surrounded by and entrapped within an amphiphilic polymer, wherein said active compound is in a non-crystalline state and said inclusion complex is stabilized by non-valent interactions between the active compound and the surrounding amphiphilic polymer, and wherein said inclusion complex is selected from the group consisting of:
(i) an inclusion complex wherein the active compound is a macrolide antibiotic selected from clarithromycin and azithromycin, and when the active compound is clarithromycin then the amphiphilic polymer is alginate or chitosan, and when the active compound is azithromycin then the amphiphilic polymer is a polysaccharide or polyvinyl alcohol;
(ii) an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide;
(iii) an inclusion complex wherein the active compound is an azole compound and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid; and (iv) an inclusion complex wherein the active compound is a taxane and the amphiphilic polymer is gelatin.
In one preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is the macrolide antibiotic clarithromycin or the first azalide antibiotic, azithromycin. These macrolides are laxge, lipophilic molecules, broad-spectrum antibiotics active against a wide variety of bacteria and can be used both in human and veterinary medicine. Macrolide antibiotics are particularly useful in treating respiratory infections.
Polymers suitable for the preparation of inclusion complexes with the macrolide antibiotics are polysaccharides, in natural form or modified. In one embodiment, the polysaccharide is starch that should preferably have a large proportion of linear chains, i.e. starch with high contents of amylose, the constituent of starch in which anhydroglucose units are linked by (-D-1,4 glucosidic bonds to form linear chains, and low contents of amylopectin, a constituent of starch having a polymeric, branched structure. The levels of amylose and amylopectin and their molecular weight vary between different starch types.
To improve its characteristics for use in the invention, starch, e.g. corn or potato starch, can be modified, for example by increasing its hydrophilicity by acid hydrolysis, e.g., with citric acid, and/or by reaction with an agent, e.g.
polyethylene glycol (PEG) and/or hydrogen peroxide. In addition, starch can be subjected to thermal treatment, for example at 160-180°C, for about 30-60 min, to reduce the amount of branching, optionally after treatment with PEG and/or hydrogen peroxide (hereinafter designated "thermodestructed starch") In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is clarithromycin and the amphiphilic polysaccharide is selected from the group consisting of starch, chitosan and alginate, e.g. sodium alginate. The starch may be hydrolyzed starch, starch modified by different amounts of PEG, preferably PEG-400, and/or by H202, and thermodestructed starch.
In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is azithromycin and the amphiphilic polysaccharide is chitosan or an alginate derivative such as propylene glycol alginate (Manucol ester B). In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is azithromycin and the amphiphilic polymer is polyvinyl alcohol (PVA).
In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide.
Donepezil, 1-benzyl-4-((5,6-dimethoxy-1-indanon)-2-yl)methylpiperidine, and analogues, were described in US 4,895,841 as acetylcholinesterase inhibitors and useful for treatment of various kinds of dementia including Alzheimer senile dementia, Huntington's chorea, Pick's disease, and ataxia. Donepezil hydrochloride is a white crystalline powder and is freely soluble in chloroform, soluble in water and in glacial acetic acid, slightly soluble in ethanol and in acetonitrile and practically insoluble in ethyl acetate and in n-hexane. Donepezil hydrochloride is available for oral administration in film-coated tablets containing 5 or 10 mg of donepezil hydrochloride for treatment of mild to moderate dementia of the Alzheimer's type. Amorphous donepezil hydrochloride is mentioned in the patents US 5,985,864 and US 6,140,321. Recently, US 6,734,195 disclosed that wet granulation of donepezil hydrochloride yields, after drying and milling, a stable granulate that uniformly contains donepezil hydrochloride amorphous.
In accordance with the present invention, water-soluble nano-particles are provided comprising inclusion complexes in which the donepezil hydrocloride in a non-crystalline state, e.g. amorphous state, is wrapped by an amphiphilic polysaccharide and is fixatedlstabilized by non-valent interactions with the surrounding amphiphilic polysaccharide. In one preferred embodiment, the polysaccharide is alginate. In another preferred embodiment, the polysaccharide is sodium starch glycolate. In still another embodiment, the polysaccharide is pregelatinized modified starch.
In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is an azole compound and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid.
Azole compounds play a key role as antifungals in agriculture and in human mycoses and as nonsteroidal antiestrogens in the treatment of estrogen-responsive breast tumors in postmenopausal women. This broad use of azoles is based on their inhibition of certain pathways of steroidogenesis by high-affinity binding to the enzymes sterol 14-demethylase and aromatase. Azole fungicides show a broad antifungal activity and are used either to prevent fungal infections or to cure an infection. Therefore, they are important tools in integrated agricultural production.
According to their chemical structure, azole compounds are classified into triazoles and imidazoles; however, their antifungal activity is due to the same molecular mechanism. Azole fungicides are broadly used in agriculture and in human and veterinary antimycotic therapies.
In accordance with the present invention, an "azole compound" refers to imidazole and triazole compounds for human or veterinary application or for use in the agriculture.
In one preferred embodiment, the azole compound is selected from azole fungicides used in many different antimycotic formulations including, but not limited to the triazoles terconazole, itraconazole, and fluconazole, and the imidazoles clotrimazole, miconazole, econazole, ketoconazole, tioconazole, isoconazole, oxiconazole, and fenticonazole.
In another embodiment, the azole compound is selected from azoles that act as nonsteroidal antiestrogens and can be used in the treatment of estrogen responsive breast tumors in postmenopausal women, including, but not limited to letrozole, anastrozole, vorozole, and fadrozole.
In another embodiment, the azole compound is an azole fungicide useful in the agriculture including, but not limited to, the triazoles bitertanol, cyproconazole, difenoconazole, epoxiconazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, metconazole, myclobutanil, penconazole, propiconazole, tebuconazole, triadimefon, triadimenol, and triticonazole, and the imidazoles imazalil, prochloraz, and triflumizole. In still another embodiment, the azole compound is a nonfungicidal azole for use in the agriculture such as the triazoles azocyclotin used as an acaricide, paclobutrazole as a growth regulator, carfentrazone as a herbicide, and isazophos as an insecticide, and the imidazole metazachlor used as herbicide.
In one more preferred embodiment, the azole compound is itraconazole, an azole medicine used to treat fungal infections. It is effective against a broad spectrum of fungi including dermatophytes (tinea infections), yeasts such as candida and malassezia infections, and systemic fungal infections such as histoplasma, aspergillus, coccidiodomycosis, chromo-blastomycosis. Itraconazole is available as 100 mg capsules under the trademark SporanoxTM (Janssen-Cilag). It is a white to slightly yellowish powder. It is lipophilic, insoluble in water, very slightly soluble in alcohols, and freely soluble in dichloromethane. Sporanox contains 100 mg of itraconazole coated on sugar spheres.
In one embodiment, the amphiphilic polymer used to wrap the azole compound is a polysaccharide, more preferably chitosan or hydrolyzed or thermodestructed starch, both optionally modified by PEG, HZOZ or both.
Alginate can also be used with certain concentrations of the azole compound (see Table hereinbelow).
In another embodiment, the amphiphilic polymer used to wrap the azole compound is selected from the group consisting of polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid.
The copolymers of poly(meth)acrylic acid may be copolymers of (meth)acrylic acid with another (meth)acrylic derivative, e.g. alkyl (meth)acrylate. In one preferred embodiment, the amphiphilic polymer is polyacrylic acid. In another preferred embodiment, the amphiphilic polymer is a copolymer of acrylic acid with butyl acrylate in different proportions (see Table 5).
In yet another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is a taxane and the amphiphilic polymer is gelatin.
As used herein, the term "taxane" refers to compounds containing the twenty carbon taxane core framework represented by the structural formula shown, for example, in US 6,201,140, herein incorporated by reference in its entirety as if fully disclosed herein. The term taxane includes the chemotherapy agents Taxol (generic name: paclitaxel; chemical name: S13, 20-epoxy-1,2a,4,713,1013,13a-hexahydroxytax-11-en-9-one, 4,10-diacetate 2-benzoate 13-ester with (2R, 3S)-N-benzoyl-3-phenylisoserine) and Taxotere (generic name: docetaxel) and semy-synthetic derivatives of taxanes having, for example, an ester or ether substituent at C(7), a hydroxy substituent at C( 10), and a range of C(2), C(9), C( 14), and side chain substituents, as described for example in the patents US 6,794,523, US
6,780,879, US 6,765,015, US 6,610,860, US 6,552,205 and US 6,201,140, all these patents being herein incorporated by reference in their entirety as if fully disclosed herein.
Taxol, an anticancer drug that now has the generic name "paclitaxel", and the registered tradename "Taxol~" (Bristol-Myers Squibb Company), is a complex polyoxygenated diterpene originally isolated from the bark of the Pacific yew tree (Taxus brevifolia). It has been approved by the FDA to treat breast, ovarian, and lung cancers as well as AIDS-related Kaposi's sarcoma. Docetaxel (Taxotere-R), a substance that is similar to paclitaxel and also comes from the needles of the yew tree, has been approved by the FDA to treat advanced breast and non-small cell lung cancers that have not responded to other anticancer drugs. Paclitaxel and docetaxel are administered intravenously. Both paclitaxel and docetaxel have side effects that can be serious. Paclitaxel is a white to off white crystalline powder. This natural compound is highly hydrophobic, insoluble in water. One problem associated with the administration of taxol is its low solubility in most pharmaceutically-acceptable solvents; the formulation used clinically contains Cremophor EL
(polyethoxylated castor oil) and ethanol as excipients, which cause serious adverse effects.
Thus, in spite of paclitaxel's good clinical efficacy and its recognized as one of the biggest advances in oncology medicine, there is still a growing need to achieve better safety and pharmacokinetic profile of paclitaxel in patients.
US 6,753,006 discloses stable, sterile, nonaqueous formulations containing a sufficient quantity of non-crystalline, cremophor-free paclitaxel to allow systemic administration to a human of a dose in the range of 30-1000 mg/m2.
In accordance with the present invention, water-soluble nano-particles are provided comprising inclusion complexes in which paclitaxel in a non-crystalline state, e.g. amorphous state, is wrapped by gelatin and is fixatedlstabilized by non-valent interactions with the surrounding gelatin. In preferred embodiments, vitamin B 12 andlor polystyrene sulfonic acid are added to the gelatin to increase solubility of paclitaxel.
The aqueous nano-dispersions of the invention can be lyophilized and then mixed with pharmaceutically acceptable carriers to provide stable pharmaceutical composition.
The pharmaceutically acceptable carriers or excipients are adapted to the type of active compound and the type of formulation and can be chosen from standard excipients as well-known in the art, for example, as described in Remington: The Science and Practice of Pharmacy (Formerly Remington's Pharmaceutical Sciences) 19th ed., 1995.
Thus, in another aspect, the present invention provides stable pharmaceutical compositions comprising pharmaceutically acceptable carriers and a nano dispersion of the invention. The compositions are intended for oral administration, intravenous administration, mucosal administration and pulmonary administration.
In a more preferred embodiment, the compositions are for oral administration, and may be in liquid or solid form. In one preferred embodiment, tablets are provided, as exemplified herein for azithromycin.
In one preferred embodiment, the invention relates to stable pharmaceutical compositions for treatment of bacterial infections comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is a macrolide antibiotic selected from the group consisting of erythromycin, clarithromycin and azithromycin and the amphiphilic polymer is a polysaccharide. These compositions can be useful for any bacterial infection treatable by said macrolide antibiotics and, particularly, for respiratory infections.
In another preferred embodiment, the invention relates to stable pharmaceutical compositions for treatment of dementia and Alzheimer's disease comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide.
In a further preferred embodiment, the invention relates to stable pharmaceutical composition for treatment of fungal infections comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is an azole fungicide and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid. In a more preferred embodiment, the azole fungicide is itraconazole and the amphiphilic polymer is selected from the group consisting of polyacrylic acid, a copolymer of acrylic acid with butyl acrylate, chitosan, and starch that has been modified by one or more of the following treatments: acid hydrolysis, reaction with polyethylene glycol or hydrogen peroxide, or thermal treatment.
In yet another preferred embodiment, the invention relates to stable pharmaceutical compositions for treatment of estrogen-responsive breast tumors comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is a nonsteroidal antiestrogen azole selected from the group consisting of letrozole, anastrozole, vorozole and fadrozole.
In still a further preferred embodiment, the invention relates to stable pharmaceutical compositions for treatment of cancer comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is a taxane, most preferably paclitaxel, and the amphiphilic polymer is gelatin.
The invention will now be illustrated by the following non-limiting examples.
EXAMPLES
Example 1. General procedure for production of the mano-particles comprising inclusion complexes For the preparation of the nano-particles of the invention, the following general procedure is carried out:
(i) preparation of a molecular solution of the amphiphilic polymer in water;
(ii) preparation of a molecular solution of the active compound in an organic solvent;
(iii) dripping the cold solution of the active compound (ii) into the polymer solution (i) heated at a temperature 5-10°C above the boiling point of the organic solvent of (ii), under constant mixing; and (iv) evaporation of the organic solvent thus obtaining the desired nano-dispersion of nano-particles comprising the inclusion complexes of the active compound entrapped within the amphiphilic polymer.
This procedure may be carried out as described previously by the inventor in the above-referenced US 2003/0129239 using the chemical reactor described therein or any suitable modification of said equipment. In accordance with the present invention, during the process of forming the soluble nano-sized particles , a polymer is added to an aqueous solvent, preferably water, to form a polymer solution in a first vessel of a chemical reactor. Additionally, ingredients may be added to adjust the pH and ionic force level of this solution as needed based on the parameters determined via the algorithm used to select the active compound and polymer. The active compound, which may be a water-insoluble (lipophilic) or a water-soluble (hydrophilic) compound, is placed in a second vessel of the chemical reactor. A solution of the active lipophilic or hydrophilic compound in a non aqueous solvent (or mixture of solvents) is referred to as the "carrier". The velocity of pouring or adding the carrier to the polymer solution is regulated by one or more regulating taps, which ensure that the organic solution being added to the polymer solution has a concentration below 3%.
The active compound solution is formed when the polymer solution is heated and steam from the heated polymer solution condenses and dissolves the active compound, present in the second vessel. The active compound solution (in carrier) is then mixed with the polymer solution to form a dispersed phase in emulsion or suspension. Within the chemical reactor, the emulsion is fed into an area of turbulence caused by a disperser (more precisely a nano-disperser) that causes the formation of nano-sized active compound molecules within the emulsion or suspension. The area of turbulence is referred to as the "action zone" or the "zone of interaction". The emulsion or suspension being fed into the area of turbulence has a Reynolds number of Re >10,000. The emulsion thus becomes a "nano-emulsion" or "nano-suspension" having particles in the range of approximately 1 to approximately 1000 nm. The particle production can also be extended to include small micron-sized particles and these particles may be suitable for several uses and are also encompassed by the present invention. Within the nano-emulsion or nano-suspension there exists a dispersion medium comprised of the polymer solution, and a dispersed phase comprising the solution of the active compound in the carrier.
This two-phased nano-emulsion or nano-suspension is, however, unstable.
Evaporating the carrier leaves particles of the dispersed phase in sizes ranging from approximately 1 to approximately 1000 nanometers. The polymer molecule in the polymer solution then surrounds or envelopes, and more appropriately wraps, the active compounds that had remained in the particles of the dispersed phase after evaporation of the carrier, thus forming a homogeneous nano-sized dispersion of water-insoluble lipophilic compound wrapped by a hydrophilic polymer in an inclusion complex. The remaining carrier is then evacuated by vacuum evaporation or other appropriate drying techniques (e.g., lyophilization, vacuum distillation).
As a result of the algorithm used to select the optimal active compound and polymer for the formation of the emulsion or suspension and resulting complex, no free polymer generally remains after the evaporation of the Garner. Following evaporation of the carrier, the stable inclusion complex is comprised of amorphous and/or partially crystalline or crystalline active entities.
Example 2. Preparation of modified starch For use in the invention, it is desirable to use starch with a large proportion of linear chains, i.e. starch with high contents of amylose, the constituent of starch in which anhydroglucose units are linked by a-D-1,4 glucosidic bonds to form linear chains, and low contents of amylopectin, a constituent of starch having a polymeric, branched structure. The levels of amylose and amylopectin and their molecular weight vary between different starch types.
To improve its characteristics for use in the invention, starch, e.g. corn or potato starch, can be modified, for example by increasing its hydrophilicity by acid hydrolysis and/or by reaction with an agent, e.g. polyethylene glycol (PEG) and or hydrogen peroxide. In addition, starch can be subjected to thermal treatment, for example at 160-180°C, for about 30-60 min, to reduce the amount of branching (hereinafter designated "thermodestructed starch").
For modification, varying amounts of potato starch and distilled water were put into a reaction vessel (C p.st=concentration of potato starch, X1 in Table 1) and citric acid was added under mixing until the desired pH (range 2-5) was attained (X2, Table 1). The obtained suspension was heated from room temperature to 70-95°C, for approximately 10-20 minutes with continuous mixing until a homogeneous opaque mass was obtained (hydrolyzed starch). The obtained mass was exposed to 160-180°C in an autoclave for time X3 (min). Under these conditions, the network structures of starch are partially or completely transformed to linear weakly branched macromolecules which dissolve in water. The mass was cooled below 100°C (thermodestructed starch).
To some of the samples, PEG-400 was added (amount X4, % in relation to starch, Table 1), the obtained mixture was heated at 160-180°C in an autoclave for time XS (Table 1), and thereafter cooled below 100°C (PEG-modified thermodestructed starch). Turbidity (in FTU, Formazin Turbidity Unit) and viscosity (molecular weight, MW) of the solution were measured. The results are shown in Table 1. The solution appropriate for further use should be transparent or opalescent, and should have preferably a turbidity within the range 20-40 FTU.
Furthermore, the molecular weight (MW) of modified starch is calculated according to intrinsic viscosity measurements. Acceptable MW (as reflected by the intrinsic viscosity) values are up to approximately 100,000 and depend on the active compound to be complexed.
Table 1. Characteristics of modified potato starch C p.st.,%PH T1 PEG-400,T2 TurbidityMW
X1 X2 min X4 % min FTU (Vise) 8 2 15 0 4 60 2 ~ 8500 C p. st= concentration of potato starch Example 3. Preparation of nano-particles comprising inclusion complexes of clarithromycin wrapped in modified starch This example is not part of the present invention but is presented to illustrate the process of preparation of the nano-particles.
For the preparation of the amphiphilic polymer, potato starch of molecular mass (5-10)x104 was dissolved in distilled water, initially heated at 160-180°C, and modified by PEG-400 as described in Example 2, using starch : PEG-400 ratio ranges between 2:1 and 4:1, solution pH (6.5 or below) adjusted with citric acid, temperature 160-180°C, and time of modification 60-180 min. A solution of clarithromycin in methyl acetate or dichloromethane was prepared.
The aqueous solution of the modified starch was put in a reaction vessel and heated up to 60°C while mixing with a homogenizer at speed of 10,000 and up rev/min. After the temperature of the starch solution reached 60°C, the clarithromycin solution was added thereto at a rate of about 1 ml/sec. The homogenizer speed was also at least 10,000 rev/min. Clarithromycin interacted with the modified starch to create nano-particles, and the organic solvent was evaporated and condensed in a direct condenser. After all the clarithromycin had interacted with the polymer and had solubilized as a clarithromycin-starch inclusion complex, the residual organic solvent was vacuum evaporated with continuous mixing, and the aqueous solution of the nano-particles comprising chlarithromycin-starch inclusion complexes was cooled to 30-35°C.
The turbidity and viscosity of the cooled aqueous solution of the nano-particles were measured for predetermined storage periods in order to assess the dispersion stability. The turbidity values for nano-dispersions of several clarithromycin-starch inclusion complexes are shown in Table 2. A stable nano-dispersion has a turbidity that remains unchanged over time. The presence of a crystalline phase, and particles sizes of the complex were determined.
Table 2. Complexes of Clarithromycin wrapped within starch Store Time Product Turbidity (FTU) at number Solution components (days) room temperature Hydrolyzed potato starch 4 27 - 5%, .
39 Clarithromycin - 1%, 10 35 pH 5.0 20 28 Hydrolyzed potato starch 0 38 - 4%, S 40 37 Clarithromycin - 2%, pH 4.5 21 36 Hydrolyzed potato starch 0 36 - 4%, 40 Clarithromycin - 2%, 1 36 pH 5.5 7 37 Hydrolyzed modified (50% 0 40 PEG) potato starch - 6%, clarithromycin - 1 %, pH 4. S
Hydrolyzed modified (25% 0 21 PEG) 34 potato starch - 3.75%, 10 20 clarithromycin - 1 %, 16 19 pH 4. S 26 20 Hydrolyzed modified (50% 0 46 PEG) 36 potato starch - 6%, 1 S 48 clarithromycin - 1.5%, 21 47 H 5.0 30 49 Hydrolyzed modified (30% 0 26 PEG) 38 potato starch - 5.2%, 4 28 clarithromycin - 1.7%, 10 27 H 5.5 20 26 Hydrolyzed modified (50% 0 38 PEG) potato starch - 12%, 1 37 43 clarithromycin - 2.5% 5 39 , pH 6.5 Hydrolyzed modified (50% 1 40 PEG) 46 potato starch - 6%, 3 44 clarithromycin - 2.5%, 9 48 pH 5.0 10 50 Hydrolyzed potato starch 0 32 - 3.75%, 47 clarithromycin - 1.5%, 1 31 H 4.5 6 35 Hydrolyzed potato starch 0 25 - 3%, 1 25 48 clarithromycin - 1.5%, 2 26 pH 5.0 g 25 Hydrolyzed potato starch 0 70 - 8%, 1 77 50 clarithromycin - 1%, 4 79 pH 5.0 6 78 Hydrolyzed modified (25% 0 64 PEG) 1 62 51 polysacharide - S%, clarithromycin - 3%, 3 61 pH 5.0 10 64 Stable Turbidity = stable nano-dispersion.
Example 4. Physical characteristics of further clarithromycin-polymer inclusion complexes Further inclusion complexes of clarithromycin hydrophilic inclusion complexes were prepared according to the method described in Example 1, in which clarithromycin was dissolved in methyl acetate or dichloromethane and the polymers were hydrolyzed potato starch, alginate, chitosan or polyvinyl alcohol (P VA).
Table 3 below shows the properties of various such complexes. Shown in Table 3 are complex designation (Exp., first column), polymer name and concentration (%), drug concentration, pH, and physico-chemical analysis of the various complexes nano-particles including ALV-size and size distribution (nm), HPLC (concentration and thus solubility) and, in some cases, powder X-ray analyses for the determination of crystalline phase. Size measurements of the complexes performed using ALV technique and powder X-ray analyses were carried out as described in Example 6 above.
Fig. 1 ilustrates the size distribution of of nano-particles comprising the clarithromycin hydrophilic inclusion complex within 1% chitosan (# 10-134 in Table 3) having a size of approximately 838 nm.
Table 3. Properties of Clarithromycin Hydrophilic Inclusion Complexes HPLC
Size Exp. Polymer Drug pH Quantity% DistributionX-Ray of (name/%) (mg/ml) (ml) Initial nm Hydrolyzed IC-76 potato 2 5 ND ND 407 ND
starch 4% dil to 2%
Hydrolyzed IC-98 potato 10 5 5 93.9 ND Amorphous starch (75) 4% dil to 2%
IC-133 2% ~ginate10 5.5 20 44.3 530 Amorphous Kelton LV
1% Chitosan _ IC-135 Fluka 10 6 5 84.5 165 Amorphous 1 C1-IZ-2% pVA 10 6 3 5 76.9 1600 Crystalline 1 Cl-IZ-1 % Chitosan 135/1- Fluka 10 4 91.3 321 ND
1 Cl-IZ-1 % Chitosan 13511- Fluka 10 6 99.6 660 ND
1 Cl-IZ-1 % Chitosan 135/2- Sigma 10 5 No 55.4 838 ND
Dil = diluted; LV=low viscosity; HPLC = High Performance Liquid Chromatography; ND
= not done As shown in Table 3, nano-particles (size below 1000 nm) could be prepared using polymers such as hydrolyzed potato starch, alginate, and chitosan from different sources, but with PVA the particles had a size of 1600 nm and the particles were crystalline and not amorphous, indicating that apparently PVA
is not useful for preparing macrolide-containing nano-particles.
The results in Table 3 show that, when the macrolide antibiotic clarithromycin, which is a poorly soluble hydrophobic compound, is surrounded by an amphiphilic polymer, the resulting inclusion complex is hydrophilic. Using the matching technique described in the instant application, clarithromycin was rendered hydrophilic when surrounded by various polymers which meet the matching parameters; such as alginate, PVA and chitosan. The results show that 2%
alginate combined with 10 mg/ml of clarithromycin at pH 5.5 resulted in nanoparticles with a ALV size distribution analysis of 530 nm; 2% PVA combined with clarithromycin at pH 6 resulted in nanoparticles with a ALV of 1600 nm;
1%
chitosan (Fluka) combined with clarithromycin at pH 4-6 resulted in a ALV of nm; 1% chitosan (Fluka) combined with clarithromycin at pH 4 resulted in an ALV
of 321 nm; 1% chitosan (Fluka) combined with clarithromycin at pH 6 resulted in an ALV of 660 nm; and 1% chitosan (Sigma) combined with clarithromycin at pH 5 resulted in an ALV of 838 nm. These results show that using the teachings of the specification (lipophilic/amphiphilic polymer matching technique), a poorly soluble hydrophobic antibiotic (clarithromycin) can be surrounded by various amphiphilic polymers (i.e. alginate, PVA and chitosan) to render the resulting inclusion complex hydrophilic in water.
It was also found that consistent spherical nano-particles of the clarithromycin-hydrolyzed starch inclusion complex IC-76 were obtained immediately and 5 weeks after preparation (not shown).
Example 5. Controlled release of clarithromycin from clarithromycin-polymer inclusion complexes via dialysis.
This experiment was carried out as described in US 2003/0129239 (in Example 7 therein), using a cellulose dialysis membrane of molecular weight cut-off of 3500 D (SnakeSkinTM Dialysis Tubing, Pierce Chemical Co., Product #68035).
Three formulations of clarithromycin were tested:
1. Commercial clarithromycin dissolved in water ( 10 mg/ml), pH 4.
2. Clarithromycin complex in 2% PVA of Table 3, with initial calculated concentration 10 mg/ml, pH=6.0 (S-Clari#34) 3. Clarithromycin complex in 1% chitosan (IC-135 of Table 3) with initial calculated concentration 10 mg/ml, pH=6.5 (S-Clari#135) Each formulation (2 ml) was put in a dialysis sac placed in a glass jar with 100 m1 water, pH=4 (titration with citrate 20%). Dialysis was performed for up to 6 hours under constant stirring at 232°C. Samples (1 ml) of external buffer were taken each hour during 5 hours of incubation for the analysis of drug release.
Volume of exterior fluid was constantly 100 ml. The concentration of clarithromycin in external (out of sac) and internal (in the sac) fluids and tested samples were determined by HPLC. The results, depicted in Fig. 2, show that release of clarithromycin from the PVA complex (S-Clari#34, squares) is faster than that of the commercial formulation (Clan, losanges), while in contrast, release of clarithromycin from the chitosan complexes (S-Clari#135, triangles) is significantly slower than that of the commercial formulation. This indicates that the nano-dispersion with chitosan has a capability to sustain the release of clarithromycin and is more suitable for the preparation of the inclusion complex with the macrolide. As shown in Table 3, the complex with PVA had a size of 1600 nm, not within the nano-range, thus it did not have sustained release.
Example 6. Physical Measurements and Characteristics of Various Azithromycin Hydrophilic Inclusion Complexes Inclusion complexes of another macrolide antibiotic, azithromycin, were prepared according to the method described in Example 1, in which azithromycin was dissolved in methyl acetate or dichloromethane and the polymers were alginate, manucol ester B (an alginate derivative), chitosan or PVA.
Table 4 below shows the properties of various such complexes. Shown in Table 4 are complex designation (Exp., first column), polymer name and concentration (%), drug concentration, pH, and physico-chemical analysis of the various complexes nano-particles including ALV-size and size distribution (nm) and HPLC (concentration and thus solubility). Size measurements of the inclusion complexes were performed using ALV-Particle Sizer (ALV-Laser GmbH, Langen, Germany), which has a resolution of 3-3000 nm. ALV is a dynamic light scattering technique used to estimate the mean particle size. Experiments are conducted with a laser-powered Noninvasive Back Scattering=High Performance Particle Sizer (ALV-NIBS/HPPS).
Fig. 3 ilustrates the size distribution of nano-particles comprising the azithromycin hydrophilic inclusion complex within 1% chitosan (# 10-148/2 in Table 4) having a size of approximately 3 62 nm. Furthermore, azithromycin in these particles was found to amorphous, as shown in the lower trace of Fig. 4, and the amorphocity was found to be stable for at least ten months. Fig. 4 illustrates X-ray spectra of 10-month old azithromycin-chitosan inclusion complex sample (bottom trace) compared to the commercially available azithromycin (upper trace).
Table 4. Properties of Azithromycin Hydrophilic Inclusion Complexes HPLC
Particle Drug % of Exp. Size Polymer (name/ %) (mg/ml) Initial Nm 2AZ-IZ-10-32 2% PVA 10 99 5 4% Manucol (Alginate) 2AZ-IZ-10-36 10 90.4 330 Ester B
2AZ-IZ-10-42 1% PVA 10 94 5 AZ-IC-131/1-IZ-10-1452% Alginate (Kelton)20 82.6 1600 LV
AZ-IC-10-42/1-IZ-10-1% pVA 10 99.32 350 AZ-IC-134/1-IZ-10-1472% Al mate Kelton 10 98.06 1060 LV
1% Chitosan (Sigma) AZ-IC 136/2-IZ-10-148 10 97.16 510 1% Chitosan (Sigma) AZ-IC 136/3-IZ-28-1 10 95.36 752 1% Chitosan (Sigma) HPLC = High Performance Liquid Chromatography assay The results in Table 4 show that when the macrolide antibiotic azithromycin, which is a poorly soluble hydrophobic compound, is surrounded by an amphiphilic polymer, the resulting inclusion complex is hydrophilic. Using the matching technique described in the instant application, azithromycin is rendered hydrophilic when surrounded by various polymers which meet the matching parameters such as alginate, PVA, Manucol Ester B, and chitosan. The results show that 2% PVA
combined with 10 mg/ml of Azithromycin resulted in a nanoparticle size distribution analysis of ALV of 5 nm; 4% Manucol Ester B combined with azithromycin resulted in an ALV of 330 nm; 1% PVA combined with azithromycin resulted in an ALV of 5 nm and, in another formulation process, 350 nm; 2%
alginate combined with azithromycin resulted in an ALV of 1600 nm and, in another formulation process, 1060 nm; 1% Chitosan (Sigma) combined with azithromycin resulted in a ALV of 510 nm and, in other formulation processes, nm and 362 nm. These results are consistent with the results above with clarithromycin and show that using the teachings of the specification (lipophilic/amphiphilic polymer matching technique), a poorly soluble hydrophobic antibiotic (azithromycin) can be surrounded by various amphiphilic polymers (i. e.
alginate, PVA, Manucol Ester B, and chitosan) to render the resulting inclusion complex hydrophilic in water.
Example 7. Physical Measurements and Characteristics of Various Itraconazole Hydrophilic Inclusion Complexes Inclusion complexes of the azole fungicide itraconazole were prepared according to the method described in Example 1, in which itraconazole was dissolved in methyl acetate or dichloromethane and the polymers were hydrolyzed potato starch, thermodestructed potato starch, alginate, chitosan, polyacrylic acid and a copolymer acrylic acid-butyl acrylate.
Table 5 below shows the properties of various such itraconazole hydrophilic inclusion complexes. Fig. 5 illustrates the size distribution of nano-particles comprising itraconazole hydrophilic inclusion complexes within thermodestructed starch (# 23-120) having a size of approximately 414 nm.
Table 5. Properties of itraconazole hydrophilic inclusion complexes HPLC
Particle Exp Drug % of Size Polymer (name/ %) (mg/ml) Initial nm 07IT-IZ-10-915% Hydrolyzed potato 2 83.8 ND
starch +
1 % H202 07IT-IZ-10-1054% Hydrolyzed potato 5 86.28 ND
starch +
1% PEG
07IT-IZ-10-1401% Chitosan Sigma C36465 ND
5% Hydrolyzed potato starch 7IT-LG-23-104 5 101.8 382 + 1 25% PEG
25% H
+ 1 .
.
5% Thermodestructed potato 7IT-LG-23-112starch S 99.5 640 + 0.625% H202 + 1.25%
PEG
5% Thermodestructed starch 7IT-LG-23-120+ 1% H202 + 2% PEG 5 100 414 5% Thermodestructed starch 7IT-LG-23-113+ 1% H 5 90.41 793 + 1% PEG
IC-131 2% Alginate Kelton) 20 101 180 LV
IC-134 2% Alginate (Kelton 10 95 1250 LV
IC-136 1% Chitosan Fluka 50494~ 8 100 120 30% Co-polymer IT-50 (acrylic acid 26.25% 10 74.2 70-80 and butyl acrylate 3.75%) 43.75% Co-polymer IT-51 (acrylic acid 38.25% 10 70.8 70-80 and butyl acr late 5.5%
33,33% Co-polymer IT-52 (acrylic acid 29.33% 10 85.5 68-109 and butyl ac late 4%
30% Co-polymer IT-OS-38-17 (acrylic acid : butyl 12 95.5 67 acrylate 24:1 IT-56 33.3% of mer (acrylic 10 91.9 85 acid) HPLC = High Performance Liquid Chromatography assay; ND = not done The results in Table 5 show that, when the anti-fungal agent itraconazole, which is an insoluble compound, is surrounded by an amphiphilic polymer, the resulting inclusion complex is hydrophilic. Using the matching technique described in the instant application, itraconazole is rendered hydrophilic when surrounded by various polymers which meet the matching parameters such as thermodestructed starch combined with H202 and PEG modification, alginate, and chitosan. The results show that 5% thermodestructed starch + 1.25% H2O2 + 1.25% PEG
combined with 5 mg/ml of iItraconazole resulted in an ALV of 382 nm; 5% thermo-destructed starch + 0.625% H202 + 1.25% PEG combined with 5 mg/ml of itraconazole resulted in an ALV of 640 nm; 5% thermodestructed starch + 1%
+ 2% PEG combined with 5 mg/ml of itraconazole resulted in an ALV of 414 nm;
5% thermodestructed starch + 1% H202 + 1% PEG combined with 5 mg/ml of itraconazole resulted in an ALV of 793 nm; 2% alginate combined with 20 mg/ml of itraconazole resulted in an ALV of 180 nm, and when combined with 10 mg/ml of itraconazole resulted in an ALV of 180 nm; 1% chitosan (Fluka) combined with ~8 mg/ml iitraconazole resulted in an ALV of 120 nm. These results show that using the teachings of the specification (lipophilic/amphiphilic polymer matching technique), the insoluble anti-fungal agent itraconazole can be surrounded by various amphiphilic polymers (i. e. thermodestructed starch combined with H202 and PEG, alginate, and chitosan) to render the resulting inclusion complex hydrophilic in water.
Differential scanning calorimetry (DSC) was done with a TA Instruments 2010 module and a 2100 System Controller to study the crystallinity of complexes.
Prior to analysis, the samples are sealed in alodined aluminum DSC pans. The tests are done at a scan rate of 10 degrees/ minute, from -50 to 200°C. Figs.
provide illustrations of itraconazole crystals and the itraconazole complexes prepared in experiment IT-56 (see Table 5), respectively. While itraconazole crystals melt at the characteristic melting point, itraconazole complexes do not melt at the characteristic point.
Example 8. Physical measurements and characteristics of various paclitaxel hydrophilic inclusion complexes Inclusion complexes of the anticancer paclitaxel were prepared according to the method described in Example 1, in which paclitaxel was dissolved in methyl acetate or dichloromethane and the polymer was gelatin of different molecular weights with or without the addition of vitamin B 12. Polyvinyl-pyrrolidone (PVP or povidone, e.g. Kollidon~' ) or polystyrene sulfonic acid can be added to increase solubilization of paclitaxel. Polystyrene sulfonic acid can also be used alone to solubilize paclitaxel.
Table 6 below shows the properties of various such paclitaxel hydrophilic inclusion complexes. Fig. 7 illustrates the size distribution of nano-particles comprising paclitaxel hydrophilic inclusion complexes within gelatin (70-100 kD, lmg/ml vitamin B 12) (# 25-85) having a size of approximately 179 nm.
Table 6. Properties of paclitaxel hydrophilic inclusion complexes in gelatin B12 Conc. Max paclitaxelParticle Exp. Polymer (MW; mg/ml) in polymer conc Size solution m m /ml nm /ml 5 TX- Gelatin OS-25- (70_100 kD; 25 mg/ml)1 0.872 179 STX- Gelatin OS-25- (70_100 kD; 25 mg/ml)0 0.646 117 STX- Gelatin OS-25- (70_100 kD; 3 mg/ml)1 3.781 129 5 TX- Gelatin OS-25- (70_100 kD; 25 mg/ml)0 0.925 186 STX- Gelatin OS-25- (70-1001{D; 6 mg/ml)0.025 6.35 297 STX- Gelatin OS-9- (250 kD; 5 mg/ml) 0 0.8 ND
5 TX- Gelatin OS-9- (250 lcD; 5 mg/ml)* 0 0.05 ND
Hydrolyzed gelatin OS 9- 0 0.066 ND
( 1 S kD; 25 mg/ml) STX- Gelatin O 0 0. 92 ND
3 5 (70-100 kD; 100 mg/ml) * *
* and 20 mg/ml Kollidon (2000-3000 kD); ** and 111 mg/ml poly (4-styrenesulfonic acid); ND = not done.
The results in Table 6 show that, when the anti-cancer agent paclitaxel, which is an insoluble compound, is surrounded by an amphiphilic polymer, the resulting inclusion complex is hydrophilic. Using the matching technique taught by the instant application, paclitaxel, at various concentrations (0.872 mg/ml, 0.646 mglml, 3.781 mg/ml and 0.925 mg/ml, for example) is rendered hydrophilic when surrounded by the polymer gelatin (optionally with added vitamin B 12 excipient) which meets the matching parameters described in the instant application Example 9. Physical measurements and characteristics of various donepezil hydrophilic inclusion complexes Inclusion complexes of donepezil hydrochloride were prepared according to the method described in Example 1, in which donepezil hydrochloride was dissolved in methyl acetate or dichloromethane and the polymers were modified corn starch , alginate, and sodium starch glycolate.
Table 7 below shows the properties of various such donepezil hydrochloride hydrophilic inclusion complexes. Fig. 8 illustrates the size distribution of nano-particles comprising donepezil hydrochloride hydrophilic inclusion complexes within modified corn starch (#LG-7-51) having a size of approximately 600 nm.
Table 7. Properties of donepezil hydrophilic inclusion complexes HPLC
Ex Polymer Drug g After ALV X-Ra DSC
. p name/% % d % nm IC-1302% ~ginate 2 5.297 ND Amorphous Amorphous Kelton LV
LG-7- 2% Na Starch Glycolate 1 5.580 ND ND Amorphous 38 Ex lotab LG-7- 1% Alginate 1 5 103 ND ND Amorphous 44 (Kelton) LV
2% Corn Starch pregelatinized, LG-7- modified 1 5 104 600 Amorphous ND
51 (PureCote~
HPLC = High Performance Liquid Chromatography assay; ND = not done.
Example 10. Oral absorption of nano-sized, water-soluble particles of azithromycin and azithromycin compositions The oral absorption of water-soluble nano-sized particles comprising inclusion complexes of 1% azithromycin and I% chitosan was studied in a preclinical model involving rats in comparison to a composition containing the commercially-available azithromycin (Azenil), in order to assess the contribution of the physical forth for enabling absorption.
Azithromycin (50 mg/kg) is administered to male Sprague-Dawley rats (groups of 5), 250-280 g, by a feeding tube. At fixed times of administration (between 1-24 hours), blood samples are collected, and sera are prepared for analysis. At the end of the study, all rats are sacrificed by an IP overdose of pental ( 100 mg/kg).
Drug concentrations in rat serum (0.1 ml) are determined by LC-MS. The samples and calibration curve are prepared as follows: fifty (50) p1 of sample are mixed with 50 ~,1 of control serum to obtain a total volume of 100 p1 of serum. The diluted samples are extracted with methyl tert-butyl ether, followed by evaporation and reconstitution in 40% aqueous acetonitrile. Analysis is performed by LC-MS, using atmospheric pressure electrospray ionization in the positive mode and an Agilent 1100 HPLC system. The azithromycin concentration is quantified by comparison with a calibration curve in the range from 20 to 2000 ng/ml, that is prepared using blank rat serum spiked with azithromycin. A plot of the concentrations (not shown) is used to determine the timing of the maximal concentration (Cmax) and to assess the total absorption of the drug (as reflected by the area under the curve (AUC).
A summary of the main pharmacokinetic findings is presented in Table 8.
These findings demonstrate that nano-sized, water-soluble particles having the same amount of azithromycin as Azenil, elevate the maximal concentration (CmaX) obtained and the total amount of azithromycin absorbed (as reflected by the AUC).
In addition, the concentration in the lung is particularly elevated, while the concentrations in other organs are increased to a less extent. Furthermore, there is no change in time at which the maximal concentration is reached.
Table 8. Comparison of pharmacokinetic parameters of azithromycin nano-sized, water-soluble particles and Azenil AUC Lung, Liver, Kidney, Heart, ' TmaX CmaX Serum 24 h 24 h 24 h 24 h SoluAzi 2 1 7 13.7 28.5 36 1.49 #55* . .
Azenil 2 0 4 6.9 18.7 31.6 1.26 (control) . .
Percent 71 76 98 52 14 18 of increase * a lot containing 1 % azithromycin and 1 % chitosan The stability of azithromycin particles, following compression, and their compatibility with tablet excipients are assessed by comparing azithromycin absorption with that of the complexes prior to tablet preparation. Tablets are prepared following lyophilization of complexes and subsequent mixture with standard acceptable excipients. The tablets are formed by application of pressure up to 1 ton/cm2. Prior to administration to rats, the tablets are dissolved in water. Then, azithromycin (50 mg/kg) is administered to male Sprague-Dawley rats (groups of 5), 250-280 g, by a feeding tube. Phartnacokinetic studies involving oral administration are done as described above.
Drug concentrations in rat serum are analyzed as described above. Plots of the serum concentrations are presented in Fig. 9. In this figure, Azenil is a marketed commercial formulation of azithromycin, while lots 28-39 and 28-59 are solutions of nano-sized, water-soluble particles comprising 1 % azithromycin complexes with 1% chitosan, and Tab28-59 is a tablet prepared from lot 28-59, dissolved in water immediately prior to administration: It is clear from this figure that the maximal concentration of azithromycin is generally reached at the same time for all of the preparations. However, absorption of azithromycin from the particles is always greater than that of the commercial formulation. Thus, as demonstrated above, enhanced absorption is apparently associated with formulations comprising the water-soluble nano-sized particles. Furthermore, the calculated area under the curve for the tablet is only about 10% less that that of the solutions comprising the water-soluble nano-sized particles. Therefore, the steps taken to prepare tablets do not adversely affect the nano-sized particles.
Example 11. Oral absorption of nano-sized, water-soluble particles of itraconazole The oral absorption of itraconazole nano-sized, water-soluble particles comprising itraconazole inclusion complexes with copolymer of acrylic acid and butyl acrylate (#IT-50, Table 5) was studied in a preclinical model involving rats and compared with oral absorption of itraconazole in compositions comprising itraconazole mixed by vortex with polyacrylic acid, which do not form nano-particles, in order to assess the contribution of the physical form for enabling absorption.
Itraconazole (50 mg/kg) is administered to male Sprague-Dawley rats (groups of 5), 250-280 g, by a feeding tube. At fixed times of administration (between 1-24 hours), blood samples are collected, and sera are prepared for analysis. At the end of the study, all rats are sacrificed by an IP overdose of pental ( 100 mg/kg).
Drug concentrations in rat serum (0.1 ml) are determined by HPLC using a method essentially as described by Yoo et al. (2002) Arch Pharm Res 25:387-391.
The samples and calibration curve are prepared as follows: samples are mixed with an equal volume of acetonitrile to obtain a total volume of 400 ~.1. KCl is added to the samples for protein precipitation, and itraconazole, in the subsequent supernatant, is applied to a Merck HPLC system. The itraconazole concentration is quantified by comparison with a calibration curve in the range from 20 to 1000 ng/mL, that is prepared using blank rat serum spiked with itraconazole. . A
plot of the concentrations (not shown) is used to determine the timing of the maximal concentration (CmaX) and to assess the total absorption of the drug (as reflected by the area under the curve (AUC).
A summary of the main pharmacokinetic findings is presented in Table 9.
These findings demonstrate that, administration of nano-sized, water-soluble particles having the same amount of intraconazole, doubles the elevated maximal blood concentrations (CmaX) of both itraconazole and its active hydroxylated metabolite (hydroxyitraconazole) and the total amount of itraconazole absorbed is increased, as reflected by the areas under the curve (AUC) of both itraconazole and its active hydroxylated metabolite.
Table 9. Comparison of pharmacokinetic parameters of itraconazole as water-soluble particles (IT-50) and as mechanical mixture (MIX) with polymer Itraconazole OH-itraconazole CrnaX0.46 0.220.72 0.3 Tmax4 4 4 4 AUC 6.9 5.813.3 9.5 I I I I
I I
Fig. 7 illustrates the size distribution of nano-particles comprising paclitaxel-gelatin inclusion complexes (# 25-85, Table 6) having a size of approximately nm, as measured by light diffraction (ALV).
Fig. 8 illustrates the size distribution of nano-particles comprising donepezil-modified starch inclusion complexes (#LG-7-51, Table 7) having a size of approximately 600 nm, as measured by light diffraction (ALV) Fig. 9 illustrates oral absorption of the following materials in a preclinical model involving rats: commercial formulation of azithromycin (Azenil), fluid formulations of nano-particles of azithromycin-chitosan inclusion complexes (from lots 28-39 and 28-59) and of lot 28-59 that were further formulated in tablet form.
DETAILED DESCRIPTION OF THE INVENTION
The nanoparticles of the present invention comprise the insoluble or soluble active compound or core, wrapped within a water-soluble amphiphilic polymer. A
variety of different polymers can be used according to the present invention for any of the selected active compound, that can be lipophilic or hydrophilic. The polymer, or groups of polymers, is selected according to an algorithm that takes into account various physical properties of both the active lipophilic or hydrophilic compound and the interaction of this compound within the resulting active compound /polymer nano-particle. This technology is fully described in the above-referenced US
2003/0129239.
One important parameter in the choice of the polymer or polymers is the HLB, i.e., the measure of the molecular balance of the hydrophilic and lipophilic portions of the compound. Within the HLB International Scale of 0-20, lipophilic molecules have a HLB of less than 6, and hydrophilic molecules have a HLB of more than 6. Thus, according to the present invention, the HLB of the polymer is selected in such a way that, after combining to it the active compound, the total resulting HLB value of the complex will be greater than 8, rendering the complex water-soluble.
As used herein, the term "non-crystalline" refers to materials both in amorphous or disordered crystalline state. In preferred embodiments, the material is amorphous. It is known by those skilled in the art that the amorphous state is preferred for drug delivery as it may indeed enhance bioavailability.
As used herein, the terms "water-soluble nano-particles", "aqueous solution of nano-particles" and "nano-dispersion" are used interchangeably and both intend to refer to the same thing, namely, to a fme dispersion of the nano-particles that may have the appearance of a solution, but is not a classical aqueous solution.
As used herein, the terms "stable nano-dispersion" and "nano-dispersion of water-soluble and stable nano-sized particles" are used interchangeably and both intend to refer to the same thing, namely, to a stable fine dispersion of the nano-particles.
Stability of the nano-particles and of the inclusion complexes has more than one meaning. The nano-particles should be stable as part of a nanocomplex over time, while remaining in the dispersion media. The nano-dispersions are stable over time without separation of phases. Furthermore, the amorphous state should be also retained over time.
It is worth noting that in the process used in the present invention, the components of the system do not result in micelles nor do they form classical dispersion systems. The technology of the present invention causes the following:
(i) after forming the inclusion complex, the poorly soluble or insoluble (or even non-wettable) active compound becomes pseudo-soluble. When the particle size is about 20-30 nm, then the material becomes soluble and visually transparent, rather than opaque;
(ii) after dispersion of the active compound to nano-size and fixation by the polymers to form an inclusion complex, enhanced solubility in physiological fluids, in vivo, improved absorption, and improved biological activity, as well as transmission to a stable non-crystalline, preferably amorphous, state, are achieved ;
(iii) a crystalline biologically-active compound becomes amorphous and thus exhibits improved biological activity.
In most preferred embodiments of the present invention, not less than 80% of the nano-particles in the nano-dispersion are within the size range, when the size deviation is not greater than 20%, and the particle size is within the nano range, namely less than 1000 nm.
In an advantageous and preferred embodiment of the invention, the polymer molecule in the polymer solution "wraps" the active compound via non-valent interactions. As used herein, the term "non-valent" is intended to refer to non-covalent, non-ionic and non-semi-polaric bonds and/or interactions, and includes, for example, electrostatic forces, Van der Waals forces, and hydrogen-bonds between the polymer and the active compound in the inclusion complex such that the non-valent interactions fixate the active compound within the polymer which thus reduces the molecular flexibility of the active compound and polymer. The formation of any valent bonds could change the characteristics or properties of the active compound. The formation of non-valent bonds preserves the structure and properties of the lipophilic compound, which is particularly important when the active compound is a pharmaceutical. _ The present invention provides a nano-dispersion of water-soluble and stable nano-sized particles comprising hydrophilic inclusion complexes consisting essentially of an active compound surrounded by and entrapped within an amphiphilic polymer, wherein said active compound is in a non-crystalline state and said inclusion complex is stabilized by non-valent interactions between the active compound and the surrounding amphiphilic polymer, and wherein said inclusion complex is selected from the group consisting of:
(i) an inclusion complex wherein the active compound is a macrolide antibiotic selected from clarithromycin and azithromycin, and when the active compound is clarithromycin then the amphiphilic polymer is alginate or chitosan, and when the active compound is azithromycin then the amphiphilic polymer is a polysaccharide or polyvinyl alcohol;
(ii) an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide;
(iii) an inclusion complex wherein the active compound is an azole compound and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid; and (iv) an inclusion complex wherein the active compound is a taxane and the amphiphilic polymer is gelatin.
In one preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is the macrolide antibiotic clarithromycin or the first azalide antibiotic, azithromycin. These macrolides are laxge, lipophilic molecules, broad-spectrum antibiotics active against a wide variety of bacteria and can be used both in human and veterinary medicine. Macrolide antibiotics are particularly useful in treating respiratory infections.
Polymers suitable for the preparation of inclusion complexes with the macrolide antibiotics are polysaccharides, in natural form or modified. In one embodiment, the polysaccharide is starch that should preferably have a large proportion of linear chains, i.e. starch with high contents of amylose, the constituent of starch in which anhydroglucose units are linked by (-D-1,4 glucosidic bonds to form linear chains, and low contents of amylopectin, a constituent of starch having a polymeric, branched structure. The levels of amylose and amylopectin and their molecular weight vary between different starch types.
To improve its characteristics for use in the invention, starch, e.g. corn or potato starch, can be modified, for example by increasing its hydrophilicity by acid hydrolysis, e.g., with citric acid, and/or by reaction with an agent, e.g.
polyethylene glycol (PEG) and/or hydrogen peroxide. In addition, starch can be subjected to thermal treatment, for example at 160-180°C, for about 30-60 min, to reduce the amount of branching, optionally after treatment with PEG and/or hydrogen peroxide (hereinafter designated "thermodestructed starch") In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is clarithromycin and the amphiphilic polysaccharide is selected from the group consisting of starch, chitosan and alginate, e.g. sodium alginate. The starch may be hydrolyzed starch, starch modified by different amounts of PEG, preferably PEG-400, and/or by H202, and thermodestructed starch.
In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is azithromycin and the amphiphilic polysaccharide is chitosan or an alginate derivative such as propylene glycol alginate (Manucol ester B). In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is azithromycin and the amphiphilic polymer is polyvinyl alcohol (PVA).
In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide.
Donepezil, 1-benzyl-4-((5,6-dimethoxy-1-indanon)-2-yl)methylpiperidine, and analogues, were described in US 4,895,841 as acetylcholinesterase inhibitors and useful for treatment of various kinds of dementia including Alzheimer senile dementia, Huntington's chorea, Pick's disease, and ataxia. Donepezil hydrochloride is a white crystalline powder and is freely soluble in chloroform, soluble in water and in glacial acetic acid, slightly soluble in ethanol and in acetonitrile and practically insoluble in ethyl acetate and in n-hexane. Donepezil hydrochloride is available for oral administration in film-coated tablets containing 5 or 10 mg of donepezil hydrochloride for treatment of mild to moderate dementia of the Alzheimer's type. Amorphous donepezil hydrochloride is mentioned in the patents US 5,985,864 and US 6,140,321. Recently, US 6,734,195 disclosed that wet granulation of donepezil hydrochloride yields, after drying and milling, a stable granulate that uniformly contains donepezil hydrochloride amorphous.
In accordance with the present invention, water-soluble nano-particles are provided comprising inclusion complexes in which the donepezil hydrocloride in a non-crystalline state, e.g. amorphous state, is wrapped by an amphiphilic polysaccharide and is fixatedlstabilized by non-valent interactions with the surrounding amphiphilic polysaccharide. In one preferred embodiment, the polysaccharide is alginate. In another preferred embodiment, the polysaccharide is sodium starch glycolate. In still another embodiment, the polysaccharide is pregelatinized modified starch.
In another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is an azole compound and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid.
Azole compounds play a key role as antifungals in agriculture and in human mycoses and as nonsteroidal antiestrogens in the treatment of estrogen-responsive breast tumors in postmenopausal women. This broad use of azoles is based on their inhibition of certain pathways of steroidogenesis by high-affinity binding to the enzymes sterol 14-demethylase and aromatase. Azole fungicides show a broad antifungal activity and are used either to prevent fungal infections or to cure an infection. Therefore, they are important tools in integrated agricultural production.
According to their chemical structure, azole compounds are classified into triazoles and imidazoles; however, their antifungal activity is due to the same molecular mechanism. Azole fungicides are broadly used in agriculture and in human and veterinary antimycotic therapies.
In accordance with the present invention, an "azole compound" refers to imidazole and triazole compounds for human or veterinary application or for use in the agriculture.
In one preferred embodiment, the azole compound is selected from azole fungicides used in many different antimycotic formulations including, but not limited to the triazoles terconazole, itraconazole, and fluconazole, and the imidazoles clotrimazole, miconazole, econazole, ketoconazole, tioconazole, isoconazole, oxiconazole, and fenticonazole.
In another embodiment, the azole compound is selected from azoles that act as nonsteroidal antiestrogens and can be used in the treatment of estrogen responsive breast tumors in postmenopausal women, including, but not limited to letrozole, anastrozole, vorozole, and fadrozole.
In another embodiment, the azole compound is an azole fungicide useful in the agriculture including, but not limited to, the triazoles bitertanol, cyproconazole, difenoconazole, epoxiconazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, metconazole, myclobutanil, penconazole, propiconazole, tebuconazole, triadimefon, triadimenol, and triticonazole, and the imidazoles imazalil, prochloraz, and triflumizole. In still another embodiment, the azole compound is a nonfungicidal azole for use in the agriculture such as the triazoles azocyclotin used as an acaricide, paclobutrazole as a growth regulator, carfentrazone as a herbicide, and isazophos as an insecticide, and the imidazole metazachlor used as herbicide.
In one more preferred embodiment, the azole compound is itraconazole, an azole medicine used to treat fungal infections. It is effective against a broad spectrum of fungi including dermatophytes (tinea infections), yeasts such as candida and malassezia infections, and systemic fungal infections such as histoplasma, aspergillus, coccidiodomycosis, chromo-blastomycosis. Itraconazole is available as 100 mg capsules under the trademark SporanoxTM (Janssen-Cilag). It is a white to slightly yellowish powder. It is lipophilic, insoluble in water, very slightly soluble in alcohols, and freely soluble in dichloromethane. Sporanox contains 100 mg of itraconazole coated on sugar spheres.
In one embodiment, the amphiphilic polymer used to wrap the azole compound is a polysaccharide, more preferably chitosan or hydrolyzed or thermodestructed starch, both optionally modified by PEG, HZOZ or both.
Alginate can also be used with certain concentrations of the azole compound (see Table hereinbelow).
In another embodiment, the amphiphilic polymer used to wrap the azole compound is selected from the group consisting of polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid.
The copolymers of poly(meth)acrylic acid may be copolymers of (meth)acrylic acid with another (meth)acrylic derivative, e.g. alkyl (meth)acrylate. In one preferred embodiment, the amphiphilic polymer is polyacrylic acid. In another preferred embodiment, the amphiphilic polymer is a copolymer of acrylic acid with butyl acrylate in different proportions (see Table 5).
In yet another preferred embodiment, the nano-particles of the invention comprise inclusion complexes in which the active compound is a taxane and the amphiphilic polymer is gelatin.
As used herein, the term "taxane" refers to compounds containing the twenty carbon taxane core framework represented by the structural formula shown, for example, in US 6,201,140, herein incorporated by reference in its entirety as if fully disclosed herein. The term taxane includes the chemotherapy agents Taxol (generic name: paclitaxel; chemical name: S13, 20-epoxy-1,2a,4,713,1013,13a-hexahydroxytax-11-en-9-one, 4,10-diacetate 2-benzoate 13-ester with (2R, 3S)-N-benzoyl-3-phenylisoserine) and Taxotere (generic name: docetaxel) and semy-synthetic derivatives of taxanes having, for example, an ester or ether substituent at C(7), a hydroxy substituent at C( 10), and a range of C(2), C(9), C( 14), and side chain substituents, as described for example in the patents US 6,794,523, US
6,780,879, US 6,765,015, US 6,610,860, US 6,552,205 and US 6,201,140, all these patents being herein incorporated by reference in their entirety as if fully disclosed herein.
Taxol, an anticancer drug that now has the generic name "paclitaxel", and the registered tradename "Taxol~" (Bristol-Myers Squibb Company), is a complex polyoxygenated diterpene originally isolated from the bark of the Pacific yew tree (Taxus brevifolia). It has been approved by the FDA to treat breast, ovarian, and lung cancers as well as AIDS-related Kaposi's sarcoma. Docetaxel (Taxotere-R), a substance that is similar to paclitaxel and also comes from the needles of the yew tree, has been approved by the FDA to treat advanced breast and non-small cell lung cancers that have not responded to other anticancer drugs. Paclitaxel and docetaxel are administered intravenously. Both paclitaxel and docetaxel have side effects that can be serious. Paclitaxel is a white to off white crystalline powder. This natural compound is highly hydrophobic, insoluble in water. One problem associated with the administration of taxol is its low solubility in most pharmaceutically-acceptable solvents; the formulation used clinically contains Cremophor EL
(polyethoxylated castor oil) and ethanol as excipients, which cause serious adverse effects.
Thus, in spite of paclitaxel's good clinical efficacy and its recognized as one of the biggest advances in oncology medicine, there is still a growing need to achieve better safety and pharmacokinetic profile of paclitaxel in patients.
US 6,753,006 discloses stable, sterile, nonaqueous formulations containing a sufficient quantity of non-crystalline, cremophor-free paclitaxel to allow systemic administration to a human of a dose in the range of 30-1000 mg/m2.
In accordance with the present invention, water-soluble nano-particles are provided comprising inclusion complexes in which paclitaxel in a non-crystalline state, e.g. amorphous state, is wrapped by gelatin and is fixatedlstabilized by non-valent interactions with the surrounding gelatin. In preferred embodiments, vitamin B 12 andlor polystyrene sulfonic acid are added to the gelatin to increase solubility of paclitaxel.
The aqueous nano-dispersions of the invention can be lyophilized and then mixed with pharmaceutically acceptable carriers to provide stable pharmaceutical composition.
The pharmaceutically acceptable carriers or excipients are adapted to the type of active compound and the type of formulation and can be chosen from standard excipients as well-known in the art, for example, as described in Remington: The Science and Practice of Pharmacy (Formerly Remington's Pharmaceutical Sciences) 19th ed., 1995.
Thus, in another aspect, the present invention provides stable pharmaceutical compositions comprising pharmaceutically acceptable carriers and a nano dispersion of the invention. The compositions are intended for oral administration, intravenous administration, mucosal administration and pulmonary administration.
In a more preferred embodiment, the compositions are for oral administration, and may be in liquid or solid form. In one preferred embodiment, tablets are provided, as exemplified herein for azithromycin.
In one preferred embodiment, the invention relates to stable pharmaceutical compositions for treatment of bacterial infections comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is a macrolide antibiotic selected from the group consisting of erythromycin, clarithromycin and azithromycin and the amphiphilic polymer is a polysaccharide. These compositions can be useful for any bacterial infection treatable by said macrolide antibiotics and, particularly, for respiratory infections.
In another preferred embodiment, the invention relates to stable pharmaceutical compositions for treatment of dementia and Alzheimer's disease comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide.
In a further preferred embodiment, the invention relates to stable pharmaceutical composition for treatment of fungal infections comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is an azole fungicide and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid. In a more preferred embodiment, the azole fungicide is itraconazole and the amphiphilic polymer is selected from the group consisting of polyacrylic acid, a copolymer of acrylic acid with butyl acrylate, chitosan, and starch that has been modified by one or more of the following treatments: acid hydrolysis, reaction with polyethylene glycol or hydrogen peroxide, or thermal treatment.
In yet another preferred embodiment, the invention relates to stable pharmaceutical compositions for treatment of estrogen-responsive breast tumors comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is a nonsteroidal antiestrogen azole selected from the group consisting of letrozole, anastrozole, vorozole and fadrozole.
In still a further preferred embodiment, the invention relates to stable pharmaceutical compositions for treatment of cancer comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is a taxane, most preferably paclitaxel, and the amphiphilic polymer is gelatin.
The invention will now be illustrated by the following non-limiting examples.
EXAMPLES
Example 1. General procedure for production of the mano-particles comprising inclusion complexes For the preparation of the nano-particles of the invention, the following general procedure is carried out:
(i) preparation of a molecular solution of the amphiphilic polymer in water;
(ii) preparation of a molecular solution of the active compound in an organic solvent;
(iii) dripping the cold solution of the active compound (ii) into the polymer solution (i) heated at a temperature 5-10°C above the boiling point of the organic solvent of (ii), under constant mixing; and (iv) evaporation of the organic solvent thus obtaining the desired nano-dispersion of nano-particles comprising the inclusion complexes of the active compound entrapped within the amphiphilic polymer.
This procedure may be carried out as described previously by the inventor in the above-referenced US 2003/0129239 using the chemical reactor described therein or any suitable modification of said equipment. In accordance with the present invention, during the process of forming the soluble nano-sized particles , a polymer is added to an aqueous solvent, preferably water, to form a polymer solution in a first vessel of a chemical reactor. Additionally, ingredients may be added to adjust the pH and ionic force level of this solution as needed based on the parameters determined via the algorithm used to select the active compound and polymer. The active compound, which may be a water-insoluble (lipophilic) or a water-soluble (hydrophilic) compound, is placed in a second vessel of the chemical reactor. A solution of the active lipophilic or hydrophilic compound in a non aqueous solvent (or mixture of solvents) is referred to as the "carrier". The velocity of pouring or adding the carrier to the polymer solution is regulated by one or more regulating taps, which ensure that the organic solution being added to the polymer solution has a concentration below 3%.
The active compound solution is formed when the polymer solution is heated and steam from the heated polymer solution condenses and dissolves the active compound, present in the second vessel. The active compound solution (in carrier) is then mixed with the polymer solution to form a dispersed phase in emulsion or suspension. Within the chemical reactor, the emulsion is fed into an area of turbulence caused by a disperser (more precisely a nano-disperser) that causes the formation of nano-sized active compound molecules within the emulsion or suspension. The area of turbulence is referred to as the "action zone" or the "zone of interaction". The emulsion or suspension being fed into the area of turbulence has a Reynolds number of Re >10,000. The emulsion thus becomes a "nano-emulsion" or "nano-suspension" having particles in the range of approximately 1 to approximately 1000 nm. The particle production can also be extended to include small micron-sized particles and these particles may be suitable for several uses and are also encompassed by the present invention. Within the nano-emulsion or nano-suspension there exists a dispersion medium comprised of the polymer solution, and a dispersed phase comprising the solution of the active compound in the carrier.
This two-phased nano-emulsion or nano-suspension is, however, unstable.
Evaporating the carrier leaves particles of the dispersed phase in sizes ranging from approximately 1 to approximately 1000 nanometers. The polymer molecule in the polymer solution then surrounds or envelopes, and more appropriately wraps, the active compounds that had remained in the particles of the dispersed phase after evaporation of the carrier, thus forming a homogeneous nano-sized dispersion of water-insoluble lipophilic compound wrapped by a hydrophilic polymer in an inclusion complex. The remaining carrier is then evacuated by vacuum evaporation or other appropriate drying techniques (e.g., lyophilization, vacuum distillation).
As a result of the algorithm used to select the optimal active compound and polymer for the formation of the emulsion or suspension and resulting complex, no free polymer generally remains after the evaporation of the Garner. Following evaporation of the carrier, the stable inclusion complex is comprised of amorphous and/or partially crystalline or crystalline active entities.
Example 2. Preparation of modified starch For use in the invention, it is desirable to use starch with a large proportion of linear chains, i.e. starch with high contents of amylose, the constituent of starch in which anhydroglucose units are linked by a-D-1,4 glucosidic bonds to form linear chains, and low contents of amylopectin, a constituent of starch having a polymeric, branched structure. The levels of amylose and amylopectin and their molecular weight vary between different starch types.
To improve its characteristics for use in the invention, starch, e.g. corn or potato starch, can be modified, for example by increasing its hydrophilicity by acid hydrolysis and/or by reaction with an agent, e.g. polyethylene glycol (PEG) and or hydrogen peroxide. In addition, starch can be subjected to thermal treatment, for example at 160-180°C, for about 30-60 min, to reduce the amount of branching (hereinafter designated "thermodestructed starch").
For modification, varying amounts of potato starch and distilled water were put into a reaction vessel (C p.st=concentration of potato starch, X1 in Table 1) and citric acid was added under mixing until the desired pH (range 2-5) was attained (X2, Table 1). The obtained suspension was heated from room temperature to 70-95°C, for approximately 10-20 minutes with continuous mixing until a homogeneous opaque mass was obtained (hydrolyzed starch). The obtained mass was exposed to 160-180°C in an autoclave for time X3 (min). Under these conditions, the network structures of starch are partially or completely transformed to linear weakly branched macromolecules which dissolve in water. The mass was cooled below 100°C (thermodestructed starch).
To some of the samples, PEG-400 was added (amount X4, % in relation to starch, Table 1), the obtained mixture was heated at 160-180°C in an autoclave for time XS (Table 1), and thereafter cooled below 100°C (PEG-modified thermodestructed starch). Turbidity (in FTU, Formazin Turbidity Unit) and viscosity (molecular weight, MW) of the solution were measured. The results are shown in Table 1. The solution appropriate for further use should be transparent or opalescent, and should have preferably a turbidity within the range 20-40 FTU.
Furthermore, the molecular weight (MW) of modified starch is calculated according to intrinsic viscosity measurements. Acceptable MW (as reflected by the intrinsic viscosity) values are up to approximately 100,000 and depend on the active compound to be complexed.
Table 1. Characteristics of modified potato starch C p.st.,%PH T1 PEG-400,T2 TurbidityMW
X1 X2 min X4 % min FTU (Vise) 8 2 15 0 4 60 2 ~ 8500 C p. st= concentration of potato starch Example 3. Preparation of nano-particles comprising inclusion complexes of clarithromycin wrapped in modified starch This example is not part of the present invention but is presented to illustrate the process of preparation of the nano-particles.
For the preparation of the amphiphilic polymer, potato starch of molecular mass (5-10)x104 was dissolved in distilled water, initially heated at 160-180°C, and modified by PEG-400 as described in Example 2, using starch : PEG-400 ratio ranges between 2:1 and 4:1, solution pH (6.5 or below) adjusted with citric acid, temperature 160-180°C, and time of modification 60-180 min. A solution of clarithromycin in methyl acetate or dichloromethane was prepared.
The aqueous solution of the modified starch was put in a reaction vessel and heated up to 60°C while mixing with a homogenizer at speed of 10,000 and up rev/min. After the temperature of the starch solution reached 60°C, the clarithromycin solution was added thereto at a rate of about 1 ml/sec. The homogenizer speed was also at least 10,000 rev/min. Clarithromycin interacted with the modified starch to create nano-particles, and the organic solvent was evaporated and condensed in a direct condenser. After all the clarithromycin had interacted with the polymer and had solubilized as a clarithromycin-starch inclusion complex, the residual organic solvent was vacuum evaporated with continuous mixing, and the aqueous solution of the nano-particles comprising chlarithromycin-starch inclusion complexes was cooled to 30-35°C.
The turbidity and viscosity of the cooled aqueous solution of the nano-particles were measured for predetermined storage periods in order to assess the dispersion stability. The turbidity values for nano-dispersions of several clarithromycin-starch inclusion complexes are shown in Table 2. A stable nano-dispersion has a turbidity that remains unchanged over time. The presence of a crystalline phase, and particles sizes of the complex were determined.
Table 2. Complexes of Clarithromycin wrapped within starch Store Time Product Turbidity (FTU) at number Solution components (days) room temperature Hydrolyzed potato starch 4 27 - 5%, .
39 Clarithromycin - 1%, 10 35 pH 5.0 20 28 Hydrolyzed potato starch 0 38 - 4%, S 40 37 Clarithromycin - 2%, pH 4.5 21 36 Hydrolyzed potato starch 0 36 - 4%, 40 Clarithromycin - 2%, 1 36 pH 5.5 7 37 Hydrolyzed modified (50% 0 40 PEG) potato starch - 6%, clarithromycin - 1 %, pH 4. S
Hydrolyzed modified (25% 0 21 PEG) 34 potato starch - 3.75%, 10 20 clarithromycin - 1 %, 16 19 pH 4. S 26 20 Hydrolyzed modified (50% 0 46 PEG) 36 potato starch - 6%, 1 S 48 clarithromycin - 1.5%, 21 47 H 5.0 30 49 Hydrolyzed modified (30% 0 26 PEG) 38 potato starch - 5.2%, 4 28 clarithromycin - 1.7%, 10 27 H 5.5 20 26 Hydrolyzed modified (50% 0 38 PEG) potato starch - 12%, 1 37 43 clarithromycin - 2.5% 5 39 , pH 6.5 Hydrolyzed modified (50% 1 40 PEG) 46 potato starch - 6%, 3 44 clarithromycin - 2.5%, 9 48 pH 5.0 10 50 Hydrolyzed potato starch 0 32 - 3.75%, 47 clarithromycin - 1.5%, 1 31 H 4.5 6 35 Hydrolyzed potato starch 0 25 - 3%, 1 25 48 clarithromycin - 1.5%, 2 26 pH 5.0 g 25 Hydrolyzed potato starch 0 70 - 8%, 1 77 50 clarithromycin - 1%, 4 79 pH 5.0 6 78 Hydrolyzed modified (25% 0 64 PEG) 1 62 51 polysacharide - S%, clarithromycin - 3%, 3 61 pH 5.0 10 64 Stable Turbidity = stable nano-dispersion.
Example 4. Physical characteristics of further clarithromycin-polymer inclusion complexes Further inclusion complexes of clarithromycin hydrophilic inclusion complexes were prepared according to the method described in Example 1, in which clarithromycin was dissolved in methyl acetate or dichloromethane and the polymers were hydrolyzed potato starch, alginate, chitosan or polyvinyl alcohol (P VA).
Table 3 below shows the properties of various such complexes. Shown in Table 3 are complex designation (Exp., first column), polymer name and concentration (%), drug concentration, pH, and physico-chemical analysis of the various complexes nano-particles including ALV-size and size distribution (nm), HPLC (concentration and thus solubility) and, in some cases, powder X-ray analyses for the determination of crystalline phase. Size measurements of the complexes performed using ALV technique and powder X-ray analyses were carried out as described in Example 6 above.
Fig. 1 ilustrates the size distribution of of nano-particles comprising the clarithromycin hydrophilic inclusion complex within 1% chitosan (# 10-134 in Table 3) having a size of approximately 838 nm.
Table 3. Properties of Clarithromycin Hydrophilic Inclusion Complexes HPLC
Size Exp. Polymer Drug pH Quantity% DistributionX-Ray of (name/%) (mg/ml) (ml) Initial nm Hydrolyzed IC-76 potato 2 5 ND ND 407 ND
starch 4% dil to 2%
Hydrolyzed IC-98 potato 10 5 5 93.9 ND Amorphous starch (75) 4% dil to 2%
IC-133 2% ~ginate10 5.5 20 44.3 530 Amorphous Kelton LV
1% Chitosan _ IC-135 Fluka 10 6 5 84.5 165 Amorphous 1 C1-IZ-2% pVA 10 6 3 5 76.9 1600 Crystalline 1 Cl-IZ-1 % Chitosan 135/1- Fluka 10 4 91.3 321 ND
1 Cl-IZ-1 % Chitosan 13511- Fluka 10 6 99.6 660 ND
1 Cl-IZ-1 % Chitosan 135/2- Sigma 10 5 No 55.4 838 ND
Dil = diluted; LV=low viscosity; HPLC = High Performance Liquid Chromatography; ND
= not done As shown in Table 3, nano-particles (size below 1000 nm) could be prepared using polymers such as hydrolyzed potato starch, alginate, and chitosan from different sources, but with PVA the particles had a size of 1600 nm and the particles were crystalline and not amorphous, indicating that apparently PVA
is not useful for preparing macrolide-containing nano-particles.
The results in Table 3 show that, when the macrolide antibiotic clarithromycin, which is a poorly soluble hydrophobic compound, is surrounded by an amphiphilic polymer, the resulting inclusion complex is hydrophilic. Using the matching technique described in the instant application, clarithromycin was rendered hydrophilic when surrounded by various polymers which meet the matching parameters; such as alginate, PVA and chitosan. The results show that 2%
alginate combined with 10 mg/ml of clarithromycin at pH 5.5 resulted in nanoparticles with a ALV size distribution analysis of 530 nm; 2% PVA combined with clarithromycin at pH 6 resulted in nanoparticles with a ALV of 1600 nm;
1%
chitosan (Fluka) combined with clarithromycin at pH 4-6 resulted in a ALV of nm; 1% chitosan (Fluka) combined with clarithromycin at pH 4 resulted in an ALV
of 321 nm; 1% chitosan (Fluka) combined with clarithromycin at pH 6 resulted in an ALV of 660 nm; and 1% chitosan (Sigma) combined with clarithromycin at pH 5 resulted in an ALV of 838 nm. These results show that using the teachings of the specification (lipophilic/amphiphilic polymer matching technique), a poorly soluble hydrophobic antibiotic (clarithromycin) can be surrounded by various amphiphilic polymers (i.e. alginate, PVA and chitosan) to render the resulting inclusion complex hydrophilic in water.
It was also found that consistent spherical nano-particles of the clarithromycin-hydrolyzed starch inclusion complex IC-76 were obtained immediately and 5 weeks after preparation (not shown).
Example 5. Controlled release of clarithromycin from clarithromycin-polymer inclusion complexes via dialysis.
This experiment was carried out as described in US 2003/0129239 (in Example 7 therein), using a cellulose dialysis membrane of molecular weight cut-off of 3500 D (SnakeSkinTM Dialysis Tubing, Pierce Chemical Co., Product #68035).
Three formulations of clarithromycin were tested:
1. Commercial clarithromycin dissolved in water ( 10 mg/ml), pH 4.
2. Clarithromycin complex in 2% PVA of Table 3, with initial calculated concentration 10 mg/ml, pH=6.0 (S-Clari#34) 3. Clarithromycin complex in 1% chitosan (IC-135 of Table 3) with initial calculated concentration 10 mg/ml, pH=6.5 (S-Clari#135) Each formulation (2 ml) was put in a dialysis sac placed in a glass jar with 100 m1 water, pH=4 (titration with citrate 20%). Dialysis was performed for up to 6 hours under constant stirring at 232°C. Samples (1 ml) of external buffer were taken each hour during 5 hours of incubation for the analysis of drug release.
Volume of exterior fluid was constantly 100 ml. The concentration of clarithromycin in external (out of sac) and internal (in the sac) fluids and tested samples were determined by HPLC. The results, depicted in Fig. 2, show that release of clarithromycin from the PVA complex (S-Clari#34, squares) is faster than that of the commercial formulation (Clan, losanges), while in contrast, release of clarithromycin from the chitosan complexes (S-Clari#135, triangles) is significantly slower than that of the commercial formulation. This indicates that the nano-dispersion with chitosan has a capability to sustain the release of clarithromycin and is more suitable for the preparation of the inclusion complex with the macrolide. As shown in Table 3, the complex with PVA had a size of 1600 nm, not within the nano-range, thus it did not have sustained release.
Example 6. Physical Measurements and Characteristics of Various Azithromycin Hydrophilic Inclusion Complexes Inclusion complexes of another macrolide antibiotic, azithromycin, were prepared according to the method described in Example 1, in which azithromycin was dissolved in methyl acetate or dichloromethane and the polymers were alginate, manucol ester B (an alginate derivative), chitosan or PVA.
Table 4 below shows the properties of various such complexes. Shown in Table 4 are complex designation (Exp., first column), polymer name and concentration (%), drug concentration, pH, and physico-chemical analysis of the various complexes nano-particles including ALV-size and size distribution (nm) and HPLC (concentration and thus solubility). Size measurements of the inclusion complexes were performed using ALV-Particle Sizer (ALV-Laser GmbH, Langen, Germany), which has a resolution of 3-3000 nm. ALV is a dynamic light scattering technique used to estimate the mean particle size. Experiments are conducted with a laser-powered Noninvasive Back Scattering=High Performance Particle Sizer (ALV-NIBS/HPPS).
Fig. 3 ilustrates the size distribution of nano-particles comprising the azithromycin hydrophilic inclusion complex within 1% chitosan (# 10-148/2 in Table 4) having a size of approximately 3 62 nm. Furthermore, azithromycin in these particles was found to amorphous, as shown in the lower trace of Fig. 4, and the amorphocity was found to be stable for at least ten months. Fig. 4 illustrates X-ray spectra of 10-month old azithromycin-chitosan inclusion complex sample (bottom trace) compared to the commercially available azithromycin (upper trace).
Table 4. Properties of Azithromycin Hydrophilic Inclusion Complexes HPLC
Particle Drug % of Exp. Size Polymer (name/ %) (mg/ml) Initial Nm 2AZ-IZ-10-32 2% PVA 10 99 5 4% Manucol (Alginate) 2AZ-IZ-10-36 10 90.4 330 Ester B
2AZ-IZ-10-42 1% PVA 10 94 5 AZ-IC-131/1-IZ-10-1452% Alginate (Kelton)20 82.6 1600 LV
AZ-IC-10-42/1-IZ-10-1% pVA 10 99.32 350 AZ-IC-134/1-IZ-10-1472% Al mate Kelton 10 98.06 1060 LV
1% Chitosan (Sigma) AZ-IC 136/2-IZ-10-148 10 97.16 510 1% Chitosan (Sigma) AZ-IC 136/3-IZ-28-1 10 95.36 752 1% Chitosan (Sigma) HPLC = High Performance Liquid Chromatography assay The results in Table 4 show that when the macrolide antibiotic azithromycin, which is a poorly soluble hydrophobic compound, is surrounded by an amphiphilic polymer, the resulting inclusion complex is hydrophilic. Using the matching technique described in the instant application, azithromycin is rendered hydrophilic when surrounded by various polymers which meet the matching parameters such as alginate, PVA, Manucol Ester B, and chitosan. The results show that 2% PVA
combined with 10 mg/ml of Azithromycin resulted in a nanoparticle size distribution analysis of ALV of 5 nm; 4% Manucol Ester B combined with azithromycin resulted in an ALV of 330 nm; 1% PVA combined with azithromycin resulted in an ALV of 5 nm and, in another formulation process, 350 nm; 2%
alginate combined with azithromycin resulted in an ALV of 1600 nm and, in another formulation process, 1060 nm; 1% Chitosan (Sigma) combined with azithromycin resulted in a ALV of 510 nm and, in other formulation processes, nm and 362 nm. These results are consistent with the results above with clarithromycin and show that using the teachings of the specification (lipophilic/amphiphilic polymer matching technique), a poorly soluble hydrophobic antibiotic (azithromycin) can be surrounded by various amphiphilic polymers (i. e.
alginate, PVA, Manucol Ester B, and chitosan) to render the resulting inclusion complex hydrophilic in water.
Example 7. Physical Measurements and Characteristics of Various Itraconazole Hydrophilic Inclusion Complexes Inclusion complexes of the azole fungicide itraconazole were prepared according to the method described in Example 1, in which itraconazole was dissolved in methyl acetate or dichloromethane and the polymers were hydrolyzed potato starch, thermodestructed potato starch, alginate, chitosan, polyacrylic acid and a copolymer acrylic acid-butyl acrylate.
Table 5 below shows the properties of various such itraconazole hydrophilic inclusion complexes. Fig. 5 illustrates the size distribution of nano-particles comprising itraconazole hydrophilic inclusion complexes within thermodestructed starch (# 23-120) having a size of approximately 414 nm.
Table 5. Properties of itraconazole hydrophilic inclusion complexes HPLC
Particle Exp Drug % of Size Polymer (name/ %) (mg/ml) Initial nm 07IT-IZ-10-915% Hydrolyzed potato 2 83.8 ND
starch +
1 % H202 07IT-IZ-10-1054% Hydrolyzed potato 5 86.28 ND
starch +
1% PEG
07IT-IZ-10-1401% Chitosan Sigma C36465 ND
5% Hydrolyzed potato starch 7IT-LG-23-104 5 101.8 382 + 1 25% PEG
25% H
+ 1 .
.
5% Thermodestructed potato 7IT-LG-23-112starch S 99.5 640 + 0.625% H202 + 1.25%
PEG
5% Thermodestructed starch 7IT-LG-23-120+ 1% H202 + 2% PEG 5 100 414 5% Thermodestructed starch 7IT-LG-23-113+ 1% H 5 90.41 793 + 1% PEG
IC-131 2% Alginate Kelton) 20 101 180 LV
IC-134 2% Alginate (Kelton 10 95 1250 LV
IC-136 1% Chitosan Fluka 50494~ 8 100 120 30% Co-polymer IT-50 (acrylic acid 26.25% 10 74.2 70-80 and butyl acrylate 3.75%) 43.75% Co-polymer IT-51 (acrylic acid 38.25% 10 70.8 70-80 and butyl acr late 5.5%
33,33% Co-polymer IT-52 (acrylic acid 29.33% 10 85.5 68-109 and butyl ac late 4%
30% Co-polymer IT-OS-38-17 (acrylic acid : butyl 12 95.5 67 acrylate 24:1 IT-56 33.3% of mer (acrylic 10 91.9 85 acid) HPLC = High Performance Liquid Chromatography assay; ND = not done The results in Table 5 show that, when the anti-fungal agent itraconazole, which is an insoluble compound, is surrounded by an amphiphilic polymer, the resulting inclusion complex is hydrophilic. Using the matching technique described in the instant application, itraconazole is rendered hydrophilic when surrounded by various polymers which meet the matching parameters such as thermodestructed starch combined with H202 and PEG modification, alginate, and chitosan. The results show that 5% thermodestructed starch + 1.25% H2O2 + 1.25% PEG
combined with 5 mg/ml of iItraconazole resulted in an ALV of 382 nm; 5% thermo-destructed starch + 0.625% H202 + 1.25% PEG combined with 5 mg/ml of itraconazole resulted in an ALV of 640 nm; 5% thermodestructed starch + 1%
+ 2% PEG combined with 5 mg/ml of itraconazole resulted in an ALV of 414 nm;
5% thermodestructed starch + 1% H202 + 1% PEG combined with 5 mg/ml of itraconazole resulted in an ALV of 793 nm; 2% alginate combined with 20 mg/ml of itraconazole resulted in an ALV of 180 nm, and when combined with 10 mg/ml of itraconazole resulted in an ALV of 180 nm; 1% chitosan (Fluka) combined with ~8 mg/ml iitraconazole resulted in an ALV of 120 nm. These results show that using the teachings of the specification (lipophilic/amphiphilic polymer matching technique), the insoluble anti-fungal agent itraconazole can be surrounded by various amphiphilic polymers (i. e. thermodestructed starch combined with H202 and PEG, alginate, and chitosan) to render the resulting inclusion complex hydrophilic in water.
Differential scanning calorimetry (DSC) was done with a TA Instruments 2010 module and a 2100 System Controller to study the crystallinity of complexes.
Prior to analysis, the samples are sealed in alodined aluminum DSC pans. The tests are done at a scan rate of 10 degrees/ minute, from -50 to 200°C. Figs.
provide illustrations of itraconazole crystals and the itraconazole complexes prepared in experiment IT-56 (see Table 5), respectively. While itraconazole crystals melt at the characteristic melting point, itraconazole complexes do not melt at the characteristic point.
Example 8. Physical measurements and characteristics of various paclitaxel hydrophilic inclusion complexes Inclusion complexes of the anticancer paclitaxel were prepared according to the method described in Example 1, in which paclitaxel was dissolved in methyl acetate or dichloromethane and the polymer was gelatin of different molecular weights with or without the addition of vitamin B 12. Polyvinyl-pyrrolidone (PVP or povidone, e.g. Kollidon~' ) or polystyrene sulfonic acid can be added to increase solubilization of paclitaxel. Polystyrene sulfonic acid can also be used alone to solubilize paclitaxel.
Table 6 below shows the properties of various such paclitaxel hydrophilic inclusion complexes. Fig. 7 illustrates the size distribution of nano-particles comprising paclitaxel hydrophilic inclusion complexes within gelatin (70-100 kD, lmg/ml vitamin B 12) (# 25-85) having a size of approximately 179 nm.
Table 6. Properties of paclitaxel hydrophilic inclusion complexes in gelatin B12 Conc. Max paclitaxelParticle Exp. Polymer (MW; mg/ml) in polymer conc Size solution m m /ml nm /ml 5 TX- Gelatin OS-25- (70_100 kD; 25 mg/ml)1 0.872 179 STX- Gelatin OS-25- (70_100 kD; 25 mg/ml)0 0.646 117 STX- Gelatin OS-25- (70_100 kD; 3 mg/ml)1 3.781 129 5 TX- Gelatin OS-25- (70_100 kD; 25 mg/ml)0 0.925 186 STX- Gelatin OS-25- (70-1001{D; 6 mg/ml)0.025 6.35 297 STX- Gelatin OS-9- (250 kD; 5 mg/ml) 0 0.8 ND
5 TX- Gelatin OS-9- (250 lcD; 5 mg/ml)* 0 0.05 ND
Hydrolyzed gelatin OS 9- 0 0.066 ND
( 1 S kD; 25 mg/ml) STX- Gelatin O 0 0. 92 ND
3 5 (70-100 kD; 100 mg/ml) * *
* and 20 mg/ml Kollidon (2000-3000 kD); ** and 111 mg/ml poly (4-styrenesulfonic acid); ND = not done.
The results in Table 6 show that, when the anti-cancer agent paclitaxel, which is an insoluble compound, is surrounded by an amphiphilic polymer, the resulting inclusion complex is hydrophilic. Using the matching technique taught by the instant application, paclitaxel, at various concentrations (0.872 mg/ml, 0.646 mglml, 3.781 mg/ml and 0.925 mg/ml, for example) is rendered hydrophilic when surrounded by the polymer gelatin (optionally with added vitamin B 12 excipient) which meets the matching parameters described in the instant application Example 9. Physical measurements and characteristics of various donepezil hydrophilic inclusion complexes Inclusion complexes of donepezil hydrochloride were prepared according to the method described in Example 1, in which donepezil hydrochloride was dissolved in methyl acetate or dichloromethane and the polymers were modified corn starch , alginate, and sodium starch glycolate.
Table 7 below shows the properties of various such donepezil hydrochloride hydrophilic inclusion complexes. Fig. 8 illustrates the size distribution of nano-particles comprising donepezil hydrochloride hydrophilic inclusion complexes within modified corn starch (#LG-7-51) having a size of approximately 600 nm.
Table 7. Properties of donepezil hydrophilic inclusion complexes HPLC
Ex Polymer Drug g After ALV X-Ra DSC
. p name/% % d % nm IC-1302% ~ginate 2 5.297 ND Amorphous Amorphous Kelton LV
LG-7- 2% Na Starch Glycolate 1 5.580 ND ND Amorphous 38 Ex lotab LG-7- 1% Alginate 1 5 103 ND ND Amorphous 44 (Kelton) LV
2% Corn Starch pregelatinized, LG-7- modified 1 5 104 600 Amorphous ND
51 (PureCote~
HPLC = High Performance Liquid Chromatography assay; ND = not done.
Example 10. Oral absorption of nano-sized, water-soluble particles of azithromycin and azithromycin compositions The oral absorption of water-soluble nano-sized particles comprising inclusion complexes of 1% azithromycin and I% chitosan was studied in a preclinical model involving rats in comparison to a composition containing the commercially-available azithromycin (Azenil), in order to assess the contribution of the physical forth for enabling absorption.
Azithromycin (50 mg/kg) is administered to male Sprague-Dawley rats (groups of 5), 250-280 g, by a feeding tube. At fixed times of administration (between 1-24 hours), blood samples are collected, and sera are prepared for analysis. At the end of the study, all rats are sacrificed by an IP overdose of pental ( 100 mg/kg).
Drug concentrations in rat serum (0.1 ml) are determined by LC-MS. The samples and calibration curve are prepared as follows: fifty (50) p1 of sample are mixed with 50 ~,1 of control serum to obtain a total volume of 100 p1 of serum. The diluted samples are extracted with methyl tert-butyl ether, followed by evaporation and reconstitution in 40% aqueous acetonitrile. Analysis is performed by LC-MS, using atmospheric pressure electrospray ionization in the positive mode and an Agilent 1100 HPLC system. The azithromycin concentration is quantified by comparison with a calibration curve in the range from 20 to 2000 ng/ml, that is prepared using blank rat serum spiked with azithromycin. A plot of the concentrations (not shown) is used to determine the timing of the maximal concentration (Cmax) and to assess the total absorption of the drug (as reflected by the area under the curve (AUC).
A summary of the main pharmacokinetic findings is presented in Table 8.
These findings demonstrate that nano-sized, water-soluble particles having the same amount of azithromycin as Azenil, elevate the maximal concentration (CmaX) obtained and the total amount of azithromycin absorbed (as reflected by the AUC).
In addition, the concentration in the lung is particularly elevated, while the concentrations in other organs are increased to a less extent. Furthermore, there is no change in time at which the maximal concentration is reached.
Table 8. Comparison of pharmacokinetic parameters of azithromycin nano-sized, water-soluble particles and Azenil AUC Lung, Liver, Kidney, Heart, ' TmaX CmaX Serum 24 h 24 h 24 h 24 h SoluAzi 2 1 7 13.7 28.5 36 1.49 #55* . .
Azenil 2 0 4 6.9 18.7 31.6 1.26 (control) . .
Percent 71 76 98 52 14 18 of increase * a lot containing 1 % azithromycin and 1 % chitosan The stability of azithromycin particles, following compression, and their compatibility with tablet excipients are assessed by comparing azithromycin absorption with that of the complexes prior to tablet preparation. Tablets are prepared following lyophilization of complexes and subsequent mixture with standard acceptable excipients. The tablets are formed by application of pressure up to 1 ton/cm2. Prior to administration to rats, the tablets are dissolved in water. Then, azithromycin (50 mg/kg) is administered to male Sprague-Dawley rats (groups of 5), 250-280 g, by a feeding tube. Phartnacokinetic studies involving oral administration are done as described above.
Drug concentrations in rat serum are analyzed as described above. Plots of the serum concentrations are presented in Fig. 9. In this figure, Azenil is a marketed commercial formulation of azithromycin, while lots 28-39 and 28-59 are solutions of nano-sized, water-soluble particles comprising 1 % azithromycin complexes with 1% chitosan, and Tab28-59 is a tablet prepared from lot 28-59, dissolved in water immediately prior to administration: It is clear from this figure that the maximal concentration of azithromycin is generally reached at the same time for all of the preparations. However, absorption of azithromycin from the particles is always greater than that of the commercial formulation. Thus, as demonstrated above, enhanced absorption is apparently associated with formulations comprising the water-soluble nano-sized particles. Furthermore, the calculated area under the curve for the tablet is only about 10% less that that of the solutions comprising the water-soluble nano-sized particles. Therefore, the steps taken to prepare tablets do not adversely affect the nano-sized particles.
Example 11. Oral absorption of nano-sized, water-soluble particles of itraconazole The oral absorption of itraconazole nano-sized, water-soluble particles comprising itraconazole inclusion complexes with copolymer of acrylic acid and butyl acrylate (#IT-50, Table 5) was studied in a preclinical model involving rats and compared with oral absorption of itraconazole in compositions comprising itraconazole mixed by vortex with polyacrylic acid, which do not form nano-particles, in order to assess the contribution of the physical form for enabling absorption.
Itraconazole (50 mg/kg) is administered to male Sprague-Dawley rats (groups of 5), 250-280 g, by a feeding tube. At fixed times of administration (between 1-24 hours), blood samples are collected, and sera are prepared for analysis. At the end of the study, all rats are sacrificed by an IP overdose of pental ( 100 mg/kg).
Drug concentrations in rat serum (0.1 ml) are determined by HPLC using a method essentially as described by Yoo et al. (2002) Arch Pharm Res 25:387-391.
The samples and calibration curve are prepared as follows: samples are mixed with an equal volume of acetonitrile to obtain a total volume of 400 ~.1. KCl is added to the samples for protein precipitation, and itraconazole, in the subsequent supernatant, is applied to a Merck HPLC system. The itraconazole concentration is quantified by comparison with a calibration curve in the range from 20 to 1000 ng/mL, that is prepared using blank rat serum spiked with itraconazole. . A
plot of the concentrations (not shown) is used to determine the timing of the maximal concentration (CmaX) and to assess the total absorption of the drug (as reflected by the area under the curve (AUC).
A summary of the main pharmacokinetic findings is presented in Table 9.
These findings demonstrate that, administration of nano-sized, water-soluble particles having the same amount of intraconazole, doubles the elevated maximal blood concentrations (CmaX) of both itraconazole and its active hydroxylated metabolite (hydroxyitraconazole) and the total amount of itraconazole absorbed is increased, as reflected by the areas under the curve (AUC) of both itraconazole and its active hydroxylated metabolite.
Table 9. Comparison of pharmacokinetic parameters of itraconazole as water-soluble particles (IT-50) and as mechanical mixture (MIX) with polymer Itraconazole OH-itraconazole CrnaX0.46 0.220.72 0.3 Tmax4 4 4 4 AUC 6.9 5.813.3 9.5 I I I I
I I
Claims (32)
1. A nano-dispersion of water-soluble and stable nano-sized particles comprising hydrophilic inclusion complexes consisting essentially of an active compound surrounded by and entrapped within an amphiphilic polymer, wherein said active compound is in a non-crystalline state and said inclusion complex is stabilized by non-valent interactions between the active compound and the surrounding amphiphilic polymer, and wherein said inclusion complex is selected from the group consisting of:
(i) an inclusion complex wherein the active compound is clarithromycin and the amphiphilic polymer is alginate or chitosan or the active compound is azithromycin and the amphiphilic polymer is a polysaccharide or polyvinyl alcohol;
(ii) an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide;
(iii) an inclusion complex wherein the active compound is an azole compound and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid; and (iv) an inclusion complex wherein the active compound is a taxane and the amphiphilic polymer is gelatin.
(i) an inclusion complex wherein the active compound is clarithromycin and the amphiphilic polymer is alginate or chitosan or the active compound is azithromycin and the amphiphilic polymer is a polysaccharide or polyvinyl alcohol;
(ii) an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide;
(iii) an inclusion complex wherein the active compound is an azole compound and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid; and (iv) an inclusion complex wherein the active compound is a taxane and the amphiphilic polymer is gelatin.
2. The nano-dispersion of claim 1, wherein the nano-particles comprise inclusion complexes in which the active compound is azithromycin and the amphiphilic polymer is a polysaccharide.
3. The nano-dispersion of claim 2, wherein said polysaccharide is starch or starch modified to increase its hydrophilicity, or to reduce its branching, or both.
4. The nano-dispersion of claim 3, wherein said starch is modified by one or more of the following treatments: acid hydrolysis, reaction with polyethylene glycol or hydrogen peroxide, or thermal treatment.
5. The nano-dispersion of claim 2, wherein the polysaccharide is chitosan or propylene glycol alginate.
6. The nano-dispersion of claim 1, wherein the nano-particles comprise inclusion complexes in which the active compound is azithromycin and the amphiphilic polymer is polyvinyl alcohol (PVA).
7. The nano-dispersion of claim 1, wherein the nano-particles comprise inclusion complexes in which the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide.
8. The nano-dispersion of claim 7, wherein said polysaccharide is selected from the group consisting of alginate, sodium starch glycolate and pregelatinized modified starch.
9. The nano-dispersion of claim 1, wherein the nano-particles comprise inclusion complexes in which the active compound is an azole compound and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid.
10. The nano-dispersion of claim 9, wherein the azole compound is an imidazole or triazole compound for human or veterinary application or for use in the agriculture.
11. The nano-dispersion of claim 10, wherein the azole compound is an azole fungicide selected from the group consisting of terconazole, itraconazole, fluconazole, clotrimazole, miconazole, econazole, ketoconazole, tioconazole, isoconazole, oxiconazole, and fenticonazole.
12. The nano-dispersion of claim 10, wherein the azole compound is a nonsteroidal antiestrogen selected from the group consisting of letrozole, anastrozole, vorozole, and fadrozole.
13. The nano-dispersion of claim 10, wherein the azole compound is an azole fungicide useful in the agriculture selected from the group consisting of bitertanol, cyproconazole, difenoconazole, epoxiconazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, metconazole, myclobutanil, penconazole, propiconazole, tebuconazole, triadimefon, triadimenol, and triticonazole, imazalil, prochloraz, and triflumizole.
14. The nano-dispersion of claim 10, wherein the azole compound is a nonfungicidal azole for use in the agriculture selected from the group consisting of azocyclotin, paclobutrazole, carfentrazone, isazophos, and metazachlor.
15. The nano-dispersion of any one of claims 9 to 14, wherein the amphiphilic polysaccharide is selected from the group consisting of chitosan and starch that has been modified by one or more of the following treatments: acid hydrolysis, reaction with polyethylene glycol or hydrogen peroxide, or thermal treatment.
16. The nano-dispersion of of any one of claims 9 to 14, wherein the amphiphilic polymer is polyacrylic acid or a copolymer of acrylic acid with butyl acrylate.
17. The nano-dispersion of claim 9, wherein the azole compound is itraconazole and the amphiphilic polymer is selected from the group consisting of polyacrylic acid, a copolymer of acrylic acid with butyl acrylate, chitosan, and starch that has been modified by one or more of the following treatments: acid hydrolysis, reaction with polyethylene glycol or hydrogen peroxide, or thermal treatment.
18. The nano-dispersion of claim 1, wherein the nano-particles comprise inclusion complexes in which the active compound is a taxane and the amphiphilic polymer is gelatin.
19. The nano-dispersion of claim 18, wherein the taxane is paclitaxel, docetaxel or a semy-synthetic derivative of a taxane.
20. The nano-dispersion of claim 19, wherein an agent selected from the group consisting of vitamin B12, polyvinylpyrrolidone and poly(4-styrenesulfonic acid) is added to the gelatin.
21. A process for preparation of a nano-dispersion of claim 1, the process comprising the steps of:
(i) preparing a molecular solution of the amphiphilic polymer in water;
(ii) preparing a molecular solution of the active compound in an organic solvent, wherein said active compound is selected from the group consisting of azithromycin, donepezil hydrochloride, an azole compound and a taxane;
(iii) dripping the cold solution of the active compound (ii) into the heated polymer solution (i) at a temperature 5 to 10°C above the boiling point of the organic solvent, under constant mixing; and (iv) removing the organic solvent thus obtaining the nano-dispersion comprising the nano-particles consisting of the inclusion complexes wherein said active compound is wrapped within said amphiphilic polymer via non-valent interactions.
(i) preparing a molecular solution of the amphiphilic polymer in water;
(ii) preparing a molecular solution of the active compound in an organic solvent, wherein said active compound is selected from the group consisting of azithromycin, donepezil hydrochloride, an azole compound and a taxane;
(iii) dripping the cold solution of the active compound (ii) into the heated polymer solution (i) at a temperature 5 to 10°C above the boiling point of the organic solvent, under constant mixing; and (iv) removing the organic solvent thus obtaining the nano-dispersion comprising the nano-particles consisting of the inclusion complexes wherein said active compound is wrapped within said amphiphilic polymer via non-valent interactions.
22. A stable pharmaceutical composition comprising a nano-dispersion of claim 1 and a pharmaceutically acceptable carrier.
23. The stable pharmaceutical composition of claim 22 for oral administration.
24. The stable pharmaceutical composition of claim 22 or 23 in liquid or solid form.
25. The stable pharmaceutical composition of claim 24 in the form of tablets.
26. The stable pharmaceutical composition of claim 22 for treatment of bacterial infections comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is azithromycin and the amphiphilic polymer is a polysaccharide or polyvinyl alcohol.
27. The stable pharmaceutical composition of claim 22 for treatment of dementia and Alzheimer's disease comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is donepezil hydrochloride and the amphiphilic polymer is a polysaccharide.
28. The stable pharmaceutical composition of claim 22 for treatment of fungal infections comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is an azole fungicide and the amphiphilic polymer is selected from the group consisting of a polysaccharide, polyacrylic acid, a copolymer of polyacrylic acid, polymethacrylic acid and a copolymer of polymethacrylic acid.
29. The stable pharmaceutical composition of claim 28 wherein the azole fungicide is itraconazole and the amphiphilic polymer is selected from the group consisting of polyacrylic acid, a copolymer of acrylic acid with butyl acrylate, chitosan, and starch that has been modified by one or more of the following treatments: acid hydrolysis, reaction with polyethylene glycol or hydrogen peroxide, or thermal treatment.
30. The stable pharmaceutical composition of claim 22 for treatment of estrogen-responsive breast tumors comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is a nonsteroidal antiestrogen azole selected from the group consisting of letrozole, anastrozole, vorozole and fadrozole.
31. The stable pharmaceutical composition of claim 22 for treatment of cancer comprising a nano-dispersion of water-soluble nano-particles comprising an inclusion complex wherein the active compound is a taxane and the amphiphilic polymer is gelatin.
32. The stable pharmaceutical composition of claim 31 for treatment of cancer wherein the taxane is paclitaxel.
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| IL160095A0 (en) * | 2004-01-28 | 2004-06-20 | Yissum Res Dev Co | Formulations for poorly soluble drugs |
| KR20090026345A (en) * | 2006-06-22 | 2009-03-12 | 노파르티스 아게 | Sustained release formulations of aromatase inhibitors |
| US20080107725A1 (en) * | 2006-10-13 | 2008-05-08 | Albano Antonio A | Pharmaceutical Solid Dosage Forms Comprising Amorphous Compounds Micro-Embedded in Ionic Water-Insoluble Polymers |
| JP5639475B2 (en) | 2007-11-27 | 2014-12-10 | アルギファルマ アイピーアール エーエス | Use of alginate oligomers in combating biofilms |
| WO2009126950A2 (en) * | 2008-04-11 | 2009-10-15 | Board Of Supervisors Of Louisiana State University And Agricultural And Mechanical College | Diterpene glycosides as natural solubilizers |
| KR20110066952A (en) * | 2008-09-25 | 2011-06-17 | 비브 나노, 인코포레이티드 | Methods to produce polymer nanoparticles and formulations of active ingredients |
| WO2011138701A1 (en) * | 2010-05-06 | 2011-11-10 | Basf Se | Pesticidal dispersion comprising nanostructured dispersed phase |
| TWI564008B (en) * | 2010-09-30 | 2017-01-01 | 鹽野義製藥股份有限公司 | Formulation for solubility enhancement of poorly soluble drugs |
| WO2013041975A2 (en) | 2011-08-23 | 2013-03-28 | Vive Crop Protection Inc. | Pyrethroid formulations |
| EP2793574A4 (en) | 2011-12-22 | 2015-09-02 | Vive Crop Prot Inc | Strobilurin formulations |
| JP6720443B2 (en) * | 2012-05-03 | 2020-07-08 | カラ ファーマシューティカルズ インコーポレイテッド | Pharmaceutical nanoparticles showing improved mucosal transport |
| MX2014013826A (en) * | 2012-05-16 | 2018-04-24 | Singh Mewa | Pharmaceutical compositions for the delivery of substantially water-insoluble drugs. |
| WO2015152433A1 (en) * | 2014-03-31 | 2015-10-08 | Hanmi Pharm. Co., Ltd. | Amorphous solid dispersion comprising paclitaxel, tablet comprising the same, and method for preparing the same |
| WO2016081593A1 (en) | 2014-11-19 | 2016-05-26 | Fmc Corporation | Nanosuspension formulation |
| CN105900982B (en) * | 2016-05-14 | 2019-03-29 | 成都科利隆生化有限公司 | A kind of application technology of inducer in agricultural chemicals suspension agent |
| EP3651743B1 (en) * | 2017-07-14 | 2023-10-04 | The University of Chicago | Freeze-dried formulations including nanoparticles and methods of freeze-drying |
| EP3672411A4 (en) | 2017-08-25 | 2021-05-19 | Vive Crop Protection Inc. | Multi-component, soil-applied, pesticidal compositions |
| CN112641738A (en) * | 2020-12-22 | 2021-04-13 | 迪沙药业集团有限公司 | Azithromycin tablet composition |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1203814B (en) * | 1986-06-30 | 1989-02-23 | Fidia Farmaceutici | ESTERS OF ALGINIC ACID |
| WO1997004756A2 (en) * | 1995-07-26 | 1997-02-13 | Nanosystems L.L.C. | Methacrylate backbone surfactants in nanoparticulate formulations |
| US5705190A (en) * | 1995-12-19 | 1998-01-06 | Abbott Laboratories | Controlled release formulation for poorly soluble basic drugs |
| JP3523821B2 (en) * | 2000-02-09 | 2004-04-26 | ナノキャリア株式会社 | Method for producing polymer micelle in which drug is encapsulated and polymer micelle composition |
| WO2003028700A2 (en) * | 2001-09-28 | 2003-04-10 | Solubest Ltd. | Water soluble nanoparticles of hydrophilic and hydrophobic active materials |
| US6878693B2 (en) * | 2001-09-28 | 2005-04-12 | Solubest Ltd. | Hydrophilic complexes of lipophilic materials and an apparatus and method for their production |
| DK1446010T3 (en) * | 2001-10-18 | 2009-06-22 | Teva Pharma | Stabilized azithromycin composition |
| CN1232539C (en) * | 2002-05-10 | 2005-12-21 | 刘云清 | Match of organic medicine and beta-cyclodextrin derivative and its preparing process |
| US8545830B2 (en) * | 2003-03-24 | 2013-10-01 | University Of Tennessee Research Foundation | Multi-functional polymeric materials and their uses |
-
2004
- 2004-09-29 EP EP04770581A patent/EP1670516A2/en not_active Withdrawn
- 2004-09-29 CA CA002540104A patent/CA2540104A1/en not_active Abandoned
- 2004-09-29 AU AU2004275594A patent/AU2004275594A1/en not_active Abandoned
- 2004-09-29 JP JP2006531012A patent/JP2007507489A/en not_active Abandoned
- 2004-09-29 WO PCT/IL2004/000910 patent/WO2005030257A2/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007507489A (en) | 2007-03-29 |
| WO2005030257A3 (en) | 2005-07-14 |
| AU2004275594A1 (en) | 2005-04-07 |
| WO2005030257A2 (en) | 2005-04-07 |
| EP1670516A2 (en) | 2006-06-21 |
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