WO2010056065A2 - Method for preparing microspheres and microspheres produced thereby - Google Patents

Method for preparing microspheres and microspheres produced thereby Download PDF

Info

Publication number
WO2010056065A2
WO2010056065A2 PCT/KR2009/006690 KR2009006690W WO2010056065A2 WO 2010056065 A2 WO2010056065 A2 WO 2010056065A2 KR 2009006690 W KR2009006690 W KR 2009006690W WO 2010056065 A2 WO2010056065 A2 WO 2010056065A2
Authority
WO
WIPO (PCT)
Prior art keywords
water
formate
acid
naoh
organic solvent
Prior art date
Application number
PCT/KR2009/006690
Other languages
French (fr)
Other versions
WO2010056065A3 (en
WO2010056065A9 (en
Inventor
Hong Kee Sah
Original Assignee
Ewha University-Industry Collaboration Foundation
Sk Chemicals Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to EP09826297.5A priority Critical patent/EP2376071A4/en
Application filed by Ewha University-Industry Collaboration Foundation, Sk Chemicals Co., Ltd. filed Critical Ewha University-Industry Collaboration Foundation
Priority to BRPI0921048-2A priority patent/BRPI0921048B1/en
Priority to AU2009314787A priority patent/AU2009314787B2/en
Priority to CN200980144588.5A priority patent/CN102209531B/en
Priority to CA2743600A priority patent/CA2743600C/en
Priority to MX2011004994A priority patent/MX2011004994A/en
Priority to JP2011536249A priority patent/JP5588993B2/en
Publication of WO2010056065A2 publication Critical patent/WO2010056065A2/en
Publication of WO2010056065A9 publication Critical patent/WO2010056065A9/en
Publication of WO2010056065A3 publication Critical patent/WO2010056065A3/en
Priority to US13/106,400 priority patent/US8697127B2/en
Priority to IL212875A priority patent/IL212875A/en
Priority to ZA2011/04399A priority patent/ZA201104399B/en

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/14—Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles
    • A61K9/16—Agglomerates; Granulates; Microbeadlets ; Microspheres; Pellets; Solid products obtained by spray drying, spray freeze drying, spray congealing,(multiple) emulsion solvent evaporation or extraction
    • A61K9/1682—Processes
    • A61K9/1694—Processes resulting in granules or microspheres of the matrix type containing more than 5% of excipient
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/13—Amines
    • A61K31/135—Amines having aromatic rings, e.g. ketamine, nortriptyline
    • A61K31/137—Arylalkylamines, e.g. amphetamine, epinephrine, salbutamol, ephedrine or methadone
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/21—Esters, e.g. nitroglycerine, selenocyanates
    • A61K31/27—Esters, e.g. nitroglycerine, selenocyanates of carbamic or thiocarbamic acids, meprobamate, carbachol, neostigmine
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/335—Heterocyclic compounds having oxygen as the only ring hetero atom, e.g. fungichromin
    • A61K31/337—Heterocyclic compounds having oxygen as the only ring hetero atom, e.g. fungichromin having four-membered rings, e.g. taxol
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/40—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having five-membered rings with one nitrogen as the only ring hetero atom, e.g. sulpiride, succinimide, tolmetin, buflomedil
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/41—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having five-membered rings with two or more ring hetero atoms, at least one of which being nitrogen, e.g. tetrazole
    • A61K31/4196—1,2,4-Triazoles
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/495—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with two or more nitrogen atoms as the only ring heteroatoms, e.g. piperazine or tetrazines
    • A61K31/496—Non-condensed piperazines containing further heterocyclic rings, e.g. rifampin, thiothixene or sparfloxacin
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/495—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with two or more nitrogen atoms as the only ring heteroatoms, e.g. piperazine or tetrazines
    • A61K31/505—Pyrimidines; Hydrogenated pyrimidines, e.g. trimethoprim
    • A61K31/519—Pyrimidines; Hydrogenated pyrimidines, e.g. trimethoprim ortho- or peri-condensed with heterocyclic rings
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/54—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with at least one nitrogen and one sulfur as the ring hetero atoms, e.g. sulthiame
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/54—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with at least one nitrogen and one sulfur as the ring hetero atoms, e.g. sulthiame
    • A61K31/5415—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with at least one nitrogen and one sulfur as the ring hetero atoms, e.g. sulthiame ortho- or peri-condensed with carbocyclic ring systems, e.g. phenothiazine, chlorpromazine, piroxicam
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/55—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having seven-membered rings, e.g. azelastine, pentylenetetrazole
    • A61K31/551—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having seven-membered rings, e.g. azelastine, pentylenetetrazole having two nitrogen atoms, e.g. dilazep
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/55—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having seven-membered rings, e.g. azelastine, pentylenetetrazole
    • A61K31/551—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having seven-membered rings, e.g. azelastine, pentylenetetrazole having two nitrogen atoms, e.g. dilazep
    • A61K31/5513—1,4-Benzodiazepines, e.g. diazepam or clozapine
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/56—Compounds containing cyclopenta[a]hydrophenanthrene ring systems; Derivatives thereof, e.g. steroids
    • A61K31/57—Compounds containing cyclopenta[a]hydrophenanthrene ring systems; Derivatives thereof, e.g. steroids substituted in position 17 beta by a chain of two carbon atoms, e.g. pregnane or progesterone
    • 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
    • A61K47/30—Macromolecular organic or inorganic compounds, e.g. inorganic polyphosphates
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/14—Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles
    • A61K9/16—Agglomerates; Granulates; Microbeadlets ; Microspheres; Pellets; Solid products obtained by spray drying, spray freeze drying, spray congealing,(multiple) emulsion solvent evaporation or extraction
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/14—Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles
    • A61K9/16—Agglomerates; Granulates; Microbeadlets ; Microspheres; Pellets; Solid products obtained by spray drying, spray freeze drying, spray congealing,(multiple) emulsion solvent evaporation or extraction
    • A61K9/1605—Excipients; Inactive ingredients
    • A61K9/1629—Organic macromolecular compounds
    • A61K9/1635—Organic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/14—Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles
    • A61K9/16—Agglomerates; Granulates; Microbeadlets ; Microspheres; Pellets; Solid products obtained by spray drying, spray freeze drying, spray congealing,(multiple) emulsion solvent evaporation or extraction
    • A61K9/1605—Excipients; Inactive ingredients
    • A61K9/1629—Organic macromolecular compounds
    • A61K9/1641—Organic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poloxamers
    • A61K9/1647—Polyesters, e.g. poly(lactide-co-glycolide)
    • 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
    • A61P25/18—Antipsychotics, i.e. neuroleptics; Drugs for mania or schizophrenia
    • 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
    • A61P29/00—Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
    • 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
    • A61P43/00—Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
    • 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
    • A61P5/34—Gestagens

Definitions

  • the present invention relates to a method for preparing microspheres and microspheres prepared thereby, more particularly to a method for preparing a polymeric microsphere, including preparing an emulsion including a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent and adding to the prepared emulsion a base or an acid to remove the water-insoluble organic solvent from the emulsion, a polymeric microsphere prepared thereby, and a composition for drug delivery including the microsphere.
  • microspheres are usually in a size of ⁇ m unit, and can be administered to a human or animal by intramuscular or subcutaneous injection. Further, microspheres can be produced to have a variety of drug release rates, so that the period of drug delivery can be controlled.
  • poly-d,l-lactide-co-glycolide has been most widely used as a high molecular compound.
  • PLGA is a biocompatible high molecular compound that is hydrolyzed in vivo to be converted into nontoxic lactic acid and glycolic acid. Therefore, pharmaceutical industries have made extensive studies on the development of drug formulation using PLGA, and examples of current available microsphere product produced by using PLGA include Risperdal Consta, Sandostatin LAR, Vivitrol, and Lupron Depot. Each of them is administered to a patient once to control the release of risperidone, octreotide acetate, naltrexone, and leuprolide acetate from 2 weeks to 4 months.
  • Such polymeric microspheres loaded with drugs can be conventionally produced by a solvent evaporation method or a solvent extraction method using an organic solvent such as methylene chloride and ethyl acetate.
  • a drug is dispersed or dissolved in an organic solvent in which a high molecular compound is dissolved, and then emulsified in a dispersion medium such as water to produce an oil-in-water(O/W) emulsion. Then the organic solvent in the emulsion is diffused into a dispersion medium and evaporated across the air/water interface to form the polymeric microspheres loaded with drugs. At this time, in order to accelerate the diffusion of organic solvent into the dispersion medium, a method such as organic solvent extraction using reduced pressure, increased temperature, and an excessive amount of water is used.
  • a dispersion organic solvent that is generally used to dissolve the high molecular PLGA is methylene chloride, which dissolves a PLGA copolymer well using various molecular weights and lactide:glycolide ratios and because it does not mix well with water due to the low water solubility of 1.32% by weight.
  • methylene chloride is a suitable solvent for the production of oil-in-water emulsion.
  • Due to the low boiling point of 39.8°C a small amount of methylene chloride molecules that diffused from emulsion liquid droplets into water are evaporated across the water/air interface. Such process is continuously repeated to remove methylene chloride from emulsion droplets, thereby forming microspheres. Finally, the residual methylene chloride present in microspheres is easily dried and removed due to its low boiling point.
  • methylene chloride is the most optimal solvent used for the production of emulsion in that it is very volatile, not mixed well with water, and has a lower boiling point than water
  • methylene chloride has the following problems: (a) it is a carcinogen proved by experiments; (b) it destroys theozone layer in the atmosphere to generate a toxic environment, causing an increase in human skin cancer; (c) it is one of the 38 toxic and hazardous substances announced by the agency for toxic substances and disease registry within the US Department of Health and Human Services; (d) a lot of time is required to completely remove methylene chloride in the emulsion droplets,since it has a low water solubility of about 1.32% by weight and only a small amount of methylene chloride is dissolved in water and evaporates.
  • the solvent extraction method used to produce polymeric microspheres loaded with drugs is a method for effectively extracting the organic solvent in the emulsion droplets by using a large amount of solubilizing solvent.
  • the solubilizing solvent that is generally used is water, and the degree of water solubility of the organic solvent greatly affects the amount of water needed.
  • methylene chloride has water solubility of 1.32% by weight, whereby a very large amount of water is needed for extracting methylene chloride in the emulsion.
  • ethyl acetate which has higher water solubility than methylene chloride, is mainly used. Since ethyl acetate has the water solubility of 8.7% by weight, it can be extracted by using a relatively small amount of water, as compared to methylene chloride, and it is advantageously a nonhalogenated organic solvent. However, its boiling point is 77°C and much higher than 39.8°C, which is that of methylene chloride. Thus, ethyl acetate has a drawback that the residual solvent is hard to remove when dried. Furthermore, a high molecular PLGA compound with a specific molecular weight and lactide:glycolide ratio has a characteristic of not dissolving easily in ethyl acetate.
  • 4,389,840 discloses a method for producing microspheres, in which a drug and a high molecular PLGA are dissolved in methylene chloride and then emulsified in water to produce oil in water-type emulsion, then 40 to 60% by weight of methylene chloride is removed by the evaporation process, and the residual methylene chloride is extracted using a large amount of water to produce microspheres.
  • the microspheres tend to coalesce during the drying process.
  • the microspheres may not be dispersed separately after the drying process, a problem may occur during injection and the reproducibility of drug release may decrease. Further, if the amount of the remaining solvent exceeds an allowable limit, it will be difficult to get the regulatory approval.
  • a polymer microsphere can be simply prepared by preparing an emulsion including a water-insoluble organic solvent and a dispersion solvent, and chemically decomposing the organic solvent using a base or an acid to converting it into a water-soluble solvent, so that the organic solvent remaining in the emulsion droplet is continuously diffused toward the aqueous phase, thereby effectively inducing the decomposition and hardening the emulsion droplet into a microsphere.
  • an object of the present invention is to provide a novel method for preparing a polymer microsphere by adding a base or an acid to an emulsion including a polymer, a drug, a water-insoluble organic solvent and a dispersion solvent to remove the water-insoluble organic solvent.
  • the present invention provides a method for preparing a polymeric microsphere, including:
  • the present invention further provides a polymeric microsphere prepared by the preparation method of the present invention.
  • the present invention further provides a composition for drug delivery comprising the polymer microsphere as an effective ingredient.
  • the method for preparing a polymeric microsphere of the present invention may include (a) preparing an oil-in-water (O/W), oil-in-oil (O/O) or water-in-oil-in-water (W/O/W) emulsion including a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent; and
  • An oil-in-water (O/W), oil-in-oil (O/O) or water-in-oil-in-water (W/O/W) emulsion comprising a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent is prepared.
  • the emulsion may be prepared by a method commonly used in the art. More specifically, in order to prepare an oil-in-water (O/W) type or oil-in-oil (O/O) type emulsion, a dispersed phase comprising a polymer compound, a drug and a water-insoluble organic solvent is added to a dispersion solvent.
  • O/W oil-in-water
  • O/O oil-in-oil
  • aqueous solution in which a drug is dissolved is emulsified in a water-insoluble organic solvent in which a polymer compound is dissolved, so as to form a W/O (water-in-oil) type emulsion, and then added to the dispersion solvent to produce a W/O/W (water-in-oil-in-water) type emulsion.
  • the polymer compound for preparing the polymeric microsphere may be used without limitation if it is well known in the art, however, preferably, it may be polylactic acid, polylactide, polylactic-co-glycolic acid, polylactide-co-glycolide(PLGA), polyphosphazine, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, a copolymer of lactic acid and caprolactone, polycaprolactone, polyhydroxyvalerate, polyhydroxybutyrate, polyamino acid, a copolymer of lactic acid and amino acid, and a mixture thereof.
  • the drug used in the present invention may include all of hydrophilic drugs and hydrophobic drugs and it may be used without limitation if it is able to be encapsulated to polymeric microshperes.
  • examples of the drug include progesterone, haloperidol, thiothixene, olanzapine, clozapine, bromperidol, pimozide, risperidone, ziprasidone, diazepma, ethyl loflazepate, alprazolam, nemonapride, fluoxetine, sertraline, venlafaxine, donepezil, tacrine, galantamine, rivastigmine, selegiline, ropinirole, pergolide, trihexyphenidyl, bromocriptine, benztropine, colchicine, nordazepam, etizolam, bromazepam, clotiazepam, mexazolum, buspirone, go
  • the water-insoluble organic solvent used in the present invention may be used without limitation if it is well known in the art, as long as it is capable of dissolving the polymer which is used for the preparation of the polymeric microspheres, being hydrolyzed by an acid or a base, and being hydrolyzed into water-soluble products.
  • compounds having backbone of amide, ester, anhydride and halogen acid are known to be easily hydrolyzed by an acid or a base.
  • the water-insoluble organic solvent of the present invention may be compounds having backbone of acid halogen, compounds having backbone of anhydride, compounds having backbone of phosphoric anhydride, compounds having backbone of ester, compounds having backbone of carboxylic esters, compounds having backbone of phosphoric esters, compounds having backbone of sulfuric acid esters, compounds having backbone of nitric esters, compounds having backbone of boric acid, compounds having backbone of amide and compounds having backbone of carboxylic amides, preferably, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl formate, ethyl formate, isopropyl formate, propyl formate, butyl formate, methyl dichloroacetate, methyl chloroacetate, ethyl chloroacetate, ethyl dichloroacetate, methyl fluoroacetate, methyl difluoroacetate,
  • the water-insoluble organic solvent is selected from the group consisting of ethyl acetate, methyl acetate, methyl formate, ethyl formate, isopropyl formate, propyl formate, acetic anhydride or propionic anhydride.
  • the water-insoluble organic solvent may control solubility of the drug to be encapsulated in the microsphere or control the hardening speed of the emulsion droplet, as desired, by using a co-solvent prepared by mixing one or more different organic solvents.
  • the dispersion solvent used in the present invention includes an aqueous dispersion solvent containing an emulsifier or non-aqueous dispersion solvent, and the aqueous dispersion solvent is used for the preparation of an O/W type and W/O/W type emulsion, the non-aqueous dispersion solvent is used for the preparation of an O/O type emulsion.
  • an aqueous solution containing hydrophilic emulsifier such as polyvinyl alcohol or polysorbates (for example, polysorbate 20, polysorbate 60, polysorbate 65, polysobate 80, polysorbate 85) or a co-solvent thereof can be used.
  • non-aqueous dispersion solvent silicone oil, vegetable oil, toluene, or xylene containing lipophilic emulsifier such as glycerin esters of fatty acids or lecithin can be used.
  • concentration of the emulsifier in the dispersion solvent may be 0.05 to 15% (w/v).
  • the polymer may be included in an amount of 1 to 500 parts by weight, preferably 1 to 50 parts by weight, based on 1 part by weight of the drug.
  • the concentration of the polymer in the emulsion may be 3 to 30 % (w/v).
  • the volume ratio of the dispersed phase or the W/O (water-in-oil) type emulsion to the dispersion solvent may be 1:1-100, preferably 1:3-15.
  • the volume ratio of the aqueous solution in which the drug is dissolved, to the water-insoluble organic solvent in which the polymer is dissolved may be 1:1-50, preferably 1:2-20.
  • a base or an acid solution is added to the O/W, W/O/W or O/O emulsion prepared in (a) to remove the water-insoluble organic solvent from the emulsion.
  • the removal of the water-insoluble organic solvent from the emulsion by adding a base or acid solution is preferably accomplished by hydrolysis.
  • Hydrolysis refers to a reaction which is decomposed into two products by adding water.
  • Compounds having backbone of ester are hydrolyzed into carboxylic acid and alcohol
  • compounds having backbone of anhydride are hydrolyzed into carboxylic acids
  • compounds having backbone of amide are hydrolyzed into carboxylic acid and amine
  • compounds having backbone of acid halogen are hydrolyzed into carboxylic acid and halogen acid (such as HF, HCl, HBr, HI).
  • the water-insoluble organic solvent diffused (or dissolved) in small quantity in a layer e.g., an aqueous layer (water phase)
  • a layer e.g., an aqueous layer (water phase)
  • the water-insoluble organic solvent is diffused into the aqueous layer by that amount.
  • the water-insoluble organic solvent is removed from the emulsion, thereby resulting in hardening of the emulsion droplet into a microsphere.
  • a desired polymer microsphere including the drug can be prepared.
  • the removal of the water-insoluble organic solvent from the emulsion includes, in addition to complete or substantial (to an extent not to be detected) removal of the water-insoluble organic solvent, reduction of the amount of the water-insoluble organic solvent as compared to before the addition of the acid or base.
  • the interaction between the emulsion droplet particles may be reduced and the desired microsphere may be obtained without coalescence.
  • the acid catalyzes the reaction and the base is consumed during the reaction. If amount of the acid or base be added in less molar or more molar than that of the water-insoluble organic solvent, the reaction can always occur.
  • the base solution may be added in such an amount that the molar ratio of the water-insoluble organic solvent to the base solution is 1:0.1-10, more preferably 1:0.1-5, further more preferably 1:0.2-3, the most preferably 1:0.2-1.5.
  • the base may be NaOH, LiOH, KOH, NH 4 OH, Cu(OH) 2 and Fe(OH) 3
  • the acid may be HCl, HNO 3 , H 2 SO 4, CH 3 COOH, H 3 BO 3 and H 2 CO 3
  • the base or acid is also referred to as a decomposition reagent.
  • the polymeric microsphere prepared by the method of the present invention has an average particle size of 0.1 to 3500 ⁇ m, preferably 10 to 350 ⁇ m, and may comprise a variety amount of drug, as required.
  • a drug-containing polymeric microsphere may be prepared quickly and simply without the solvent evaporation or solvent extraction process, thereby reducing water consumption and minimizing wastewater generation.
  • the polymer microsphere of the present invention is capable of effectively delivering the drug included in the polymer microsphere. Therefore, the present invention provides a composition for drug delivery comprising the polymer microsphere prepared by the preparation method of the present invention as an effective ingredient.
  • composition for drug delivery of the present invention may be applied to various diseases depending on the drug included therein.
  • nucleotide or protein processing may be referred to the following literature [Maniatis et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1982); Sambrook et al., Molecular Cloning: A Laboratory Manual, 2d Ed., Cold Spring Harbor Laboratory Press (1989); Deutscher, M., Guide to Protein Purification Methods Enzymology, vol. 182. Academic Press. Inc., San Diego, CA (1990)].
  • GC analysis was carried out in order to investigate whether ethyl acetate, ethyl formate, propyl formate, and isopropyl formate are decomposed by an acid or base in an aqueous phase.
  • no reagent was added to the aqueous phase (blank)
  • some of ethyl acetate, ethyl formate, propyl formate or isopropyl formate was transported into the aqueous phase, thereby increasing their concentration in the aqueous phase until saturation.
  • their concentration is saturated, their transportation into the aqueous phase does not occur.
  • the acid or base was added, hydrolysis continued to occur, thereby increasing the concentration of the hydrolyzed product such as ethanol continuously.
  • progesterone, anastrazole, olanzapine, risperidone, aripiprazole, docetaxel, piroxicam, rivastigmine or tolterodine was selected as target drugs, and microparticles in which the target drugs are encapsulated were prepared at various conditions. And it was observed that their properties, encapsulation ratio, residual amount of organic solvent, or the like. As a result, spherical microparticles encapsulating the target drug were prepared well, and they had high encapsulation ratio. Besides, the residual amount of organic solvent was very low level.
  • GC gas chromatography
  • Fig. 2 shows a change of ethanol and ethyl acetate concentrations in the aqueous phase depending on time.
  • A Ethanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M NaOH was added.
  • B Ethyl acetate concentration in the aqueous phase when no NaOH was added, and 2 mL or 5 mL of 10 M NaOH was added.
  • Fig. 5 shows a change of ethanol concentration in the aqueous phase depending on time.
  • A Ethanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M NaOH was added.
  • B Ethanol concentration in the aqueous phase when 2 mL or 6 mL of 10 M HCl was added.
  • Fig. 7 shows a change of propanol/propyl formate concentrations in the aqueous phase depending on time.
  • A Propanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M NaOH was added.
  • B Propyl formate concentration in the aqueous phase when no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M NaOH was added.
  • Fig. 9 shows a change of propanol/propyl formate concentrations in the aqueous phase depending on time.
  • A Propanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M HCl was added.
  • B Propyl formate concentration in the aqueous phase when no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M HCl was added.
  • Fig. 11 shows a change of isopropanol/isopropyl formate concentrations in the aqueous phase depending on time.
  • A Isopropanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M NaOH was added.
  • B Isopropyl formate concentration in the aqueous phase when no decomposition reagent was added to the aqueous phase, and 2 mL or 6 mL of 10 M HCl was added.
  • Fig. 13 shows a change of isopropanol concentration in the aqueous phase. It shows that, when 2 mL or 5 mL of 10 M HCl was added, isopropyl formate was decomposed and changed into isopropanol.
  • Fig. 14 shows a change of emulsion depending on time when a propionic anhydride/aqueous phase system (A) is stirred without adding an acid or base, (B) is stirred after adding 2 mL of strong HCl, and (C) is stirred after adding 3 mL of 10 M NaOH.
  • A propionic anhydride/aqueous phase system
  • B is stirred after adding 2 mL of strong HCl
  • C is stirred after adding 3 mL of 10 M NaOH.
  • Fig. 15 shows light micrographs of 7E microparticles prepared by using isopropyl formate as an organic solvent and using NaOH at various concentrations as a decomposition reagent.
  • A NaOH was not added (0 mL).
  • B -(F): 1, 2, 3, 4 and 5 mL of 10 M NaOH was added, respectively. When NaOH was not added, the emulsion droplets coalesced to form a polymeric film.
  • Fig. 16 shows electron micrographs of 7E microparticles prepared by using NaOH as an ethyl acetate decomposition reagent.
  • (a) Inside and outside of the microparticles prepared by using 60 mg of progesterone.
  • (b) Inside and outside of the microparticles prepared by using 250 mg of progesterone.
  • Fig. 17 shows electron micrographs of 7E microparticles prepared by using NaOH as an ethyl formate decomposition reagent.
  • (a) Inside and outside of the microparticles prepared by using 60 mg of progesterone.
  • (b) Inside and outside of the microparticles prepared by using 250 mg of progesterone.
  • Fig. 18 shows electron micrographs of microparticles prepared by using 0.25 g of 4A PLGA and NaOH as an ethyl acetate decomposition reagent.
  • (a) Inside and outside of the microparticles prepared by using 60 mg of progesterone.
  • (b) Inside and outside of the microparticles prepared by using 250 mg of progesterone.
  • Fig. 19 shows electron micrographs of microparticles prepared by using 0.25 g of 4A PLGA and NaOH as an ethyl formate decomposition reagent.
  • (a) Inside and outside of the microparticles prepared by using 60 mg of progesterone.
  • (b) Inside and outside of the microparticles prepared by using 250 mg of progesterone.
  • Fig. 20 shows electron micrographs showing outside of microparticles prepared by using 10 M NaOH as an isopropyl formate decomposition reagent.
  • 10 M NaOH as an isopropyl formate decomposition reagent.
  • a), (b), (c), (d), (e) and (f) 0, 60, 100, 160, 200 and 250 mg of progesterone was used, respectively.
  • Fig. 21 shows electron micrographs showing inside of microparticles prepared by using 10 M NaOH as an isopropyl formate decomposition reagent.
  • 10 M NaOH as an isopropyl formate decomposition reagent.
  • a), (b), (c), (d), (e) and (f) 0, 60, 100, 160, 200 and 250 mg of progesterone was used, respectively.
  • Fig. 22 shows electron micrographs of microparticles prepared by using propyl formate as an organic solvent and 2 mL of HCl as a decomposition reagent.
  • Fig. 23 shows a thermogravimetric analysis result of microparticle samples. It can be seen that the amount of the volatile residual organic solvent is extremely slight in the microparticles comprising progesterone, and is smaller than that of the microparticles not containing progesterone.
  • Fig. 24 shows electron micrographs of microparticles prepared by using 60 mg of anastrazole, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl acetate decomposition reagent.
  • Fig. 25 shows electron micrographs of microparticles prepared by using 60 mg of anastrazole, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl formate decomposition reagent.
  • Fig. 26 shows HPLC chromatograms of various samples under an anastrazole encapsulation ratio analysis condition.
  • e Anastrazole standard solution prepared by using 50% acetonitrile aqueous solution. It can be seen that a very small amount of ethyl acetate is detected from the two microparticle samples and no anastrazole modification product is detected.
  • Fig. 27 shows electron micrographs of microparticles prepared by using 60 mg of olanzapine, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl acetate decomposition reagent.
  • Fig. 28 shows electron micrographs of microparticles prepared by using 60 mg of risperidone, 0.25 g of 4A and NaOH as an ethyl formate decomposition reagent.
  • Fig. 29 shows electron micrographs of microparticles prepared by using 40 mg of aripiprazole, 0.25 g of 4A and NaOH as an ethyl formate decomposition reagent.
  • the present invention provides a novel method for preparing a polymeric microsphere comprising the step of removing a water-insoluble organic solvent using a base or an acid, a polymeric microsphere prepared by the method, and a composition for drug delivery comprising the polymeric microsphere.
  • a drug-containing polymer microsphere may be prepared quickly and simply without the solvent evaporation or solvent extraction process, thereby reducing water consumption and minimizing wastewater generation.
  • Fig. 1 shows gas chromatography (GC) chromatograms of an aqueous phase sample depending on time of an ethyl acetate/aqueous phase system following slow stirring.
  • GC gas chromatography
  • Fig. 2 shows a change of ethanol and ethyl acetate concentrations in the aqueous phase depending on time.
  • Fig. 3 shows GC chromatograms of an aqueous phase sample depending on time of an ethyl formate/aqueous phase system following slow stirring.
  • Fig. 4 shows GC chromatograms of an aqueous phase sample depending on time of an ethyl formate/aqueous phase system following slow stirring.
  • Fig. 5 shows a change of ethanol concentration in the aqueous phase depending on time.
  • Fig. 6 shows GC chromatograms of an aqueous phase sample depending on time of a propyl formate/aqueous phase system following slow stirring.
  • Fig. 7 shows a change of propanol/propyl formate concentrations in the aqueous phase depending on time.
  • Fig. 8 shows GC chromatograms of an aqueous phase sample depending on time of a propyl formate/aqueous phase system following slow stirring.
  • Fig. 9 shows a change of propanol/propyl formate concentrations in the aqueous phase depending on time.
  • Fig. 10 shows GC chromatograms of an aqueous phase sample depending on time of an isopropyl formate/aqueous phase system following slow stirring.
  • Fig. 11 shows a change of isopropanol/isopropyl formate concentrations in the aqueous phase depending on time.
  • Fig. 12 shows GC chromatograms of an aqueous phase sample depending on time of an isopropyl formate/aqueous phase system following slow stirring.
  • Fig. 13 shows a change of isopropanol concentration in the aqueous phase depending on time.
  • Fig. 14 shows a change of emulsion depending on time when a propionic anhydride/aqueous phase system (A) is stirred without adding an acid or base, (B) is stirred after adding 2 mL of strong HCl, and (C) is stirred after adding 3 mL of 10 M NaOH.
  • Fig. 15 shows light micrographs of 7E microparticles prepared by using isopropyl formate as an organic solvent and using NaOH at various concentrations as a decomposition reagent.
  • A NaOH was not added (0 mL).
  • B -(F): 1, 2, 3, 4 and 5 mL of 10 M NaOH was added, respectively.
  • Fig. 16 shows electron micrographs of 7E microparticles prepared by using NaOH as an ethyl acetate decomposition reagent.
  • Fig. 17 shows electron micrographs of 7E microparticles prepared by using NaOH as an ethyl formate decomposition reagent.
  • Fig. 18 shows electron micrographs of microparticles prepared by using 0.25 g of 4A PLGA and NaOH as an ethyl acetate decomposition reagent.
  • Fig. 19 shows electron micrographs of microparticles prepared by using 0.25 g of 4A PLGA and NaOH as an ethyl formate decomposition reagent.
  • Fig. 20 shows electron micrographs showing outside of microparticles prepared by using 10 M NaOH as an isopropyl formate decomposition reagent.
  • Fig. 21 shows electron micrographs showing inside of microparticles prepared by using 10 M NaOH as an isopropyl formate decomposition reagent.
  • Fig. 22 shows electron micrographs of microparticles prepared by using propyl formate as an organic solvent and 2 mL of HCl as a decomposition reagent.
  • Fig. 23 shows a thermogravimetric analysis result of microparticle samples.
  • Fig. 24 shows electron micrographs of microparticles prepared by using 60 mg of anastrazole, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl acetate decomposition reagent.
  • Fig. 25 shows electron micrographs of microparticles prepared by using 60 mg of anastrazole, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl formate decomposition reagent.
  • Fig. 26 shows HPLC chromatograms of various samples under an anastrazole encapsulation ratio analysis condition.
  • Fig. 27 shows electron micrographs of microparticles prepared by using 60 mg of olanzapine, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl acetate decomposition reagent.
  • Fig. 28 shows electron micrographs of microparticles prepared by using 60 mg of risperidone, 0.25 g of 4A and NaOH as an ethyl acetate decomposition reagent.
  • Fig. 29 shows electron micrographs of microparticles prepared by using 40 mg of aripiprazole, 0.25 g of 4A and NaOH as an ethyl acetate decomposition reagent.
  • GC analysis was performed with GC-2010 (Shimadzu, Japan). Zebron ZB-624 (Phenomenex, USA)analysis column using 6%-cyanopropylphenyl-94%-methylpolysiloxane as stationary phase was used. The quantity of ethyl acetate, and ethanol which is the decomposition products of ethyl acetate, was measured using isopropanol as internal standard.
  • GC analysis was performed with GC-2010 (Shimadzu, Japan). Zebron ZB-624 (Phenomenex, USA) analysis column using 6%-cyanopropylphenyl-94%-methylpolysiloxane as stationary phase was used. The quantity of ethyl formate, and ethanol which is the decomposition products of ethyl formate, was measured using methanol as internal standard.
  • GC analysis was performed with GC-2010 (Shimadzu, Japan). Zebron ZB-624 (Phenomenex, USA) analysis column using 6%-cyanopropylphenyl-94%-methylpolysiloxane as stationary phase was used. The quantity of propyl formate, and propanol which is the decomposition products of propyl formate, was measured using ethanol as internal standard.
  • GC analysis was performed with GC-2010 (Shimadzu, Japan). Zebron ZB-624 (Phenomenex, USA) analysis column using 6%-cyanopropylphenyl-94%-methylpolysiloxane as stationary phase was used. The quantity of isopropyl formate, and isopropanol which is the decomposition products of isopropyl formate, was measured using ethanol as internal standard.
  • PLGA 50:50(i.v. 0.46 dL/g in CHCl 3, its abbreviation refers to 4A)
  • PLGA 50:50(i.v. 0.18 dL/g in CHCl 3, its abbreviation refers to 2A).
  • microparticles encapsulating progesterone were prepared using ethyl formate instead of ethyl acetate and using 6 mL of 10 M NaOH or 5 mL of 10 M HCl as a decomposition reagent.
  • microspheres encapsulating progesterone were prepared well.
  • ethyl acetate or ethyl formate was used as an organic solvent, inside and outside shapes of the microparticles were similar.
  • Example ⁇ 7-1> Some of the microparticles prepared in Example ⁇ 7-1> were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with methanol, the solution was filtered to remove the PLGA precipitate. Some of the filtrate (20 ⁇ l) was subjected to HPLC (Shimadzu LC-20AD, Luna 5 m C18(2) column) for measurement of progesterone concentration. Theoretical drug load (%) and actual drug load (%) were calculated from the following equations, and their ratio was defined as drug encapsulation ratio (%).
  • Theoretical drug load (%) (Weight of drug used (mg) / [Weight of PLGA used (mg) + Weight of drug used (mg)]) x 100
  • Drug encapsulation ratio (%) (Actual drug load (%) / Theoretical drug load (%)) x 100
  • 0.25 g of 7E was dissolved in 4 mL of isopropyl formate or propyl formate. After adding and dissolving progesterone (60 or 250 mg) therein, the resultant dispersed phase was added to 40 mL of 0.5% PVA aqueous solution and stirred to prepare an o/w emulsion. After adding 4 mL of 10 M NaOH to the emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was added. After stirring and filtration, microparticles were recovered. The microparticles were redispersed in 16 mL of 0.5% PVA solution and stirred, after adding distilled water to make 80 mL. After filtration, the microparticles were in a vacuum dryer.
  • Progesterone encapsulation ratio of the microparticles prepared in Example ⁇ 7-3> was measured as in Example ⁇ 7-2>.
  • microparticles prepared using isopropyl formate as an organic solvent in Example ⁇ 7-3> were stored for 3 days in vacuum state and the quantity of isopropyl formate remaining in the microparticle was measured.
  • microparticles (about 30 mg) were accurately weighed and completely dissolved in 2 mL of methylene chloride. After diluting 5 times with butanol, the precipitated PLGA was removed by filtration. The concentration of isopropyl formate in the filtrate was measured by GC analysis in the same manner as in Example 4.
  • the microparticles prepared in the present invention showed very low residual content of isopropyl formate.
  • the residual content of the solvent was inversely proportional to the quantity of progesterone encapsulated in the microparticles.
  • microparticles prepared in Example ⁇ 7-3> using isopropyl formate, 0.25 g of 7E and 250 mg of progesterone
  • microparticles not including progesterone were analyzed using a thermogravimetric analyzer (TGA 2050). Nitrogen was used as a purge gas. Change in weight of the microparticles was automatically recorded while increasing temperature at a rate of 10 °C/min.
  • Each of 7E, 4A and 2A polymers was dissolved in 4 mL of ethyl acetate. Then, 60 mg of anastrazole was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. 5 mL of 10 M NaOH was added to the resultant o/w emulsion. After adding 40 mL of distilled water and stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
  • microparticles encapsulating progesterone were prepared using ethyl formate instead of ethyl acetateand using 6 mL of 10 M NaOH.
  • microspheres according to the method of the present invention were prepared well.
  • Example ⁇ 8-1> Some of the microparticles prepared in Example ⁇ 8-1> were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with 50% acetonitrile, the solution was filtered using a 0.45 ⁇ m syringe filter to remove the PLGA precipitate. Some of the filtrate (20 ⁇ l) was subjected to HPLC (Shimadzu LC-20AD, Luna 5 m C18(2) column) for measurement of anastrazole concentration. Drug encapsulation ratio (%) was calculated using the equations given in Example ⁇ 7-2>.
  • the microparticles according to the method of the present invention showed high encapsulation ratio and good batch reproducibility, with similar encapsulation ratios between batches.
  • anastrazole encapsulation ratio was slightly lower than when ethyl acetate was used.
  • Example ⁇ 8-1> In order to indirectly estimate whether decomposition or modification products of anastrazole are produced during the preparation of microparticles using ethyl acetate/PLGA (75:25)/NaOH as in Example ⁇ 8-1>, various samples were prepared (as in Example ⁇ 8-1>) and their chromatograms were analyzed.
  • 0.15 g of 7E and 0.1 g of 4A or 2A was dissolved in 4 mL of ethyl acetate. Then, 60 mg of olanzapine was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. After adding 5 mL of 10 M NaOH to the resultant o/w emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was further added and, after stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
  • microspheres according to the method of the present invention were prepared well.
  • microparticles including olanzapine were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with ethanol, the solution was filtered using a 0.45 ⁇ m syringe filter to remove the PLGA precipitate. Some of the filtrate (20 ⁇ l) was subjected to HPLC (Shimadzu LC-20AD, Luna 5 m C18(2) column) for measurement of olanzapine concentration. Drug encapsulation ratio (%) was calculated using the equations given in Example ⁇ 7-2>.
  • the microparticles prepared according to the method of the present invention showed high olanzapine encapsulation ratio and good batch reproducibility, with similar encapsulation ratios between batches.
  • Encapsulation ratio of 7E/4A formulation was 83.5 ⁇ 4.4%, and that for 7E/2A was 79.8 ⁇ 2.7%.
  • 0.25 g of 4A was dissolved in 4 mL of ethyl formate. Then, 60 mg of risperidone was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. After adding 5 mL of 8 M NaOH to the resultant o/w emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was further added and, after stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
  • microspheres according to the method of the present invention were prepared well.
  • microparticles including risperidone were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with ethanol, the solution was filtered to remove the PLGA precipitate. Some of the filtrate (20 ⁇ l) was subjected to HPLC (Shimadzu LC-20AD) for measurement of risperidone concentration. Drug encapsulation ratio (%) was calculated using the equations given in Example ⁇ 7-2>.
  • the microparticles prepared according to the method of the present invention showed high risperidone encapsulation ratio and good batch reproducibility, with similar encapsulation ratios between batches. Average encapsulation ratio of 3 batches was 75.0 ⁇ 1.4%.
  • 0.25 g of 4A was dissolved in 4 mL of ethyl formate. Then, 60 mg of aripiprazole was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. After adding 5 mL of 8 M NaOH to the resultant o/w emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was further added and, after stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
  • microspheres according to the method of the present invention were prepared well.
  • microparticles including aripiprazole were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with ethanol, the solution was filtered to remove the PLGA precipitate. Some of the filtrate (20 ⁇ l) was subjected to HPLC (Shimadzu LC-20AD) for measurement of aripiprazole concentration. Drug encapsulation ratio (%) was calculated using the equations given in Example ⁇ 7-2>.
  • the microparticles prepared according to the method of the present invention showed high aripiprazole encapsulation ratio and good batch reproducibility, with similar encapsulation ratios between batches. Average encapsulation ratio of 3 batches was 72.3 ⁇ 2.0%.
  • microparticles were recovered by filtration.
  • the microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
  • microparticles including each of docetaxel, piroxicam, rivastigmine or tolterodine were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with ethanol, the solution was filtered to remove the PLGA precipitate. Some of the filtrate (20 ⁇ l) was subjected to HPLC (Shimadzu LC-20AD) for measurement of docetaxel, piroxicam, rivastigmine or tolterodine concentration, respectively. Drug encapsulation ratio (%) was calculated using the equations given in Example ⁇ 7-2>.
  • the microparticles prepared according to the method of the present invention showed high drug encapsulation ratio.
  • the present invention provides a novel method for preparing a polymeric microsphere comprising the step of removing a water-insoluble organic solvent using a base or an acid, a polymeric microsphere prepared by the method, and a composition for drug delivery comprising the polymeric microsphere.
  • a drug-containing polymer microsphere may be prepared quickly and simply without the solvent evaporation or solvent extraction process, thereby reducing water consumption and minimizing wastewater generation. Therefore, the present invention can be effectively used in pharmaceutical and/or medical industry.

Landscapes

  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Veterinary Medicine (AREA)
  • Medicinal Chemistry (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Epidemiology (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Engineering & Computer Science (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Organic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Emergency Medicine (AREA)
  • Neurology (AREA)
  • Neurosurgery (AREA)
  • Biomedical Technology (AREA)
  • Psychiatry (AREA)
  • Endocrinology (AREA)
  • Diabetes (AREA)
  • Pain & Pain Management (AREA)
  • Rheumatology (AREA)
  • Hospice & Palliative Care (AREA)
  • Inorganic Chemistry (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Medicinal Preparation (AREA)
  • Manufacturing Of Micro-Capsules (AREA)
  • Processes Of Treating Macromolecular Substances (AREA)
  • Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
  • Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)

Abstract

The present invention relates to a method for preparing microspheres and microspheres prepared thereby, more particularly to a method for preparing a polymeric microsphere, including preparing an emulsion including a polymer compound, a drug, a water- insoluble organic solvent and a dispersion solvent and adding to the prepared emulsion a base or an acid to remove the water-insoluble organic solvent from the emulsion, a polymeric microsphere prepared thereby, and a composition for drug delivery including the microsphere. According to the present invention, a drug-containing polymer microsphere may be prepared quickly and simply without the solvent evaporation or solvent extraction process, thereby reducing water consumption and minimizing wastewater generation.

Description

METHOD FOR PREPARING MICROSPHERES AND MICROSPHERES PRODUCED THEREBY
The present invention relates to a method for preparing microspheres and microspheres prepared thereby, more particularly to a method for preparing a polymeric microsphere, including preparing an emulsion including a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent and adding to the prepared emulsion a base or an acid to remove the water-insoluble organic solvent from the emulsion, a polymeric microsphere prepared thereby, and a composition for drug delivery including the microsphere.
Conventional injectable formulations such as solution, suspension, and emulsion are quickly removed from the body after administration, and therefore frequent administration is essentially needed for treatment of chronic diseases. Microencapsulation has been developed to solve the problem, and referred to a production process for encapsulating drugs in microspheres (hereinafter, the term microsphere will include nanospheres) consisting of high molecular compounds. Microspheres are usually in a size of ㎛ unit, and can be administered to a human or animal by intramuscular or subcutaneous injection. Further, microspheres can be produced to have a variety of drug release rates, so that the period of drug delivery can be controlled. Therefore, evenif a therapeutic drug is administered only once, its effective concentration can be maintained over a long period of time, and the total administration amount of therapeutic drug can be minimized to improve the drug compliance in patients. Accordingly, world famous pharmaceutical companies are very interested in the production of polymeric microsphere loaded with drugs.
In the production of polymeric microspheres by microencapsulation, poly-d,l-lactide-co-glycolide (PLGA) has been most widely used as a high molecular compound. PLGA is a biocompatible high molecular compound that is hydrolyzed in vivo to be converted into nontoxic lactic acid and glycolic acid. Therefore, pharmaceutical industries have made extensive studies on the development of drug formulation using PLGA, and examples of current available microsphere product produced by using PLGA include Risperdal Consta, Sandostatin LAR, Vivitrol, and Lupron Depot. Each of them is administered to a patient once to control the release of risperidone, octreotide acetate, naltrexone, and leuprolide acetate from 2 weeks to 4 months.
Such polymeric microspheres loaded with drugs can be conventionally produced by a solvent evaporation method or a solvent extraction method using an organic solvent such as methylene chloride and ethyl acetate.
First, the solvent evaporation method will be briefly described (see US PatentNos. 6,471,996, 5,985,309, and 5,271,945). A drug is dispersed or dissolved in an organic solvent in which a high molecular compound is dissolved, and then emulsified in a dispersion medium such as water to produce an oil-in-water(O/W) emulsion. Then the organic solvent in the emulsion is diffused into a dispersion medium and evaporated across the air/water interface to form the polymeric microspheres loaded with drugs. At this time, in order to accelerate the diffusion of organic solvent into the dispersion medium, a method such as organic solvent extraction using reduced pressure, increased temperature, and an excessive amount of water is used. A dispersion organic solvent that is generally used to dissolve the high molecular PLGA is methylene chloride, which dissolves a PLGA copolymer well using various molecular weights and lactide:glycolide ratios and because it does not mix well with water due to the low water solubility of 1.32% by weight. Thus, methylene chloride is a suitable solvent for the production of oil-in-water emulsion. Further, due to the low boiling point of 39.8℃, a small amount of methylene chloride molecules that diffused from emulsion liquid droplets into water are evaporated across the water/air interface. Such process is continuously repeated to remove methylene chloride from emulsion droplets, thereby forming microspheres. Finally, the residual methylene chloride present in microspheres is easily dried and removed due to its low boiling point.
Likewise, even though methylene chloride is the most optimal solvent used for the production of emulsion in that it is very volatile, not mixed well with water, and has a lower boiling point than water, methylene chloride has the following problems: (a) it is a carcinogen proved by experiments; (b) it destroys theozone layer in the atmosphere to generate a toxic environment, causing an increase in human skin cancer; (c) it is one of the 38 toxic and hazardous substances announced by the agency for toxic substances and disease registry within the US Department of Health and Human Services; (d) a lot of time is required to completely remove methylene chloride in the emulsion droplets,since it has a low water solubility of about 1.32% by weight and only a small amount of methylene chloride is dissolved in water and evaporates. For example, in US Pat No. 6,884,435, the emulsion is stirred overnight to remove methylene chloride from the emulsion, and conditions such as increased temperature or reduced pressure in a reactor are introduced to shorten the production time of microspheres (see US Pat Nos. 3,691,090, 3,891,570, 6,270,700, and 6,572,894).
On the other hand, the solvent extraction method used to produce polymeric microspheres loaded with drugs is a method for effectively extracting the organic solvent in the emulsion droplets by using a large amount of solubilizing solvent. When the organic solvent is extracted from the emulsion droplets, the dissolved high molecular compounds are hardened to convert the emulsion droplets into microspheres. The solubilizing solvent that is generally used is water, and the degree of water solubility of the organic solvent greatly affects the amount of water needed. For example, methylene chloride has water solubility of 1.32% by weight, whereby a very large amount of water is needed for extracting methylene chloride in the emulsion. However, a large amount of wastewater containing methylene chloride is produced, in which the treatment of the wastewater becomes a problematic issue. Therefore, in the solvent extraction method, ethyl acetate, which has higher water solubility than methylene chloride, is mainly used. Since ethyl acetate has the water solubility of 8.7% by weight, it can be extracted by using a relatively small amount of water, as compared to methylene chloride, and it is advantageously a nonhalogenated organic solvent. However, its boiling point is 77℃ and much higher than 39.8℃, which is that of methylene chloride. Thus, ethyl acetate has a drawback that the residual solvent is hard to remove when dried. Furthermore, a high molecular PLGA compound with a specific molecular weight and lactide:glycolide ratio has a characteristic of not dissolving easily in ethyl acetate.
Therefore, technologies simultaneously employing the solvent evaporation method and solvent extraction method are disclosed in US Pat Nos. 4,389,840, 4,530,840, 6,544,559, 6,368,632, and 6,572,894. That is, in the methods, the emulsion is produced, and then the organic solvent is partially removed by the evaporation process, and the residual organic solvent is removed by the solvent extraction method. For example, US Pat No. 4,389,840 discloses a method for producing microspheres, in which a drug and a high molecular PLGA are dissolved in methylene chloride and then emulsified in water to produce oil in water-type emulsion, then 40 to 60% by weight of methylene chloride is removed by the evaporation process, and the residual methylene chloride is extracted using a large amount of water to produce microspheres.
However, since all of the organic solvents used in the known methods do not have sufficient high water solubility, excessively large amounts of water (over 10 times more than water solubility of organic solvent) should be used. Thus, a large-volume reactor is needed, and a large amount of wastewater containing organic solvent is produced, as a result, the cost for wastewater treatment is increased. Further, there is a problem that the residual organic solvent present in the microspheres is not effectively removed.
In particular, when a large amount of organic solvent remains in the microspheres, the microspheres tend to coalesce during the drying process. As a result, since the microspheres may not be dispersed separately after the drying process, a problem may occur during injection and the reproducibility of drug release may decrease. Further, if the amount of the remaining solvent exceeds an allowable limit, it will be difficult to get the regulatory approval.
The inventors of the present invention have researched to develop a method capable of solving the aforesaid problem and preparing a polymer microsphere including a drug in a simple and easy way. As a result, we have found that a polymer microsphere can be simply prepared by preparing an emulsion including a water-insoluble organic solvent and a dispersion solvent, and chemically decomposing the organic solvent using a base or an acid to converting it into a water-soluble solvent, so that the organic solvent remaining in the emulsion droplet is continuously diffused toward the aqueous phase, thereby effectively inducing the decomposition and hardening the emulsion droplet into a microsphere.
Accordingly, an object of the present invention is to provide a novel method for preparing a polymer microsphere by adding a base or an acid to an emulsion including a polymer, a drug, a water-insoluble organic solvent and a dispersion solvent to remove the water-insoluble organic solvent.
To achieve the object, the present invention provides a method for preparing a polymeric microsphere, including:
(a) preparing an oil-in-water (O/W), oil-in-oil (O/O) or water-in-oil-in-water (W/O/W) emulsion including a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent and
(b) adding to the emulsion prepared in (a) a base solution or an acid solution to remove the water-insoluble organic solvent from the emulsion.
The present invention further provides a polymeric microsphere prepared by the preparation method of the present invention.
To achieve the object, the present invention further provides a composition for drug delivery comprising the polymer microsphere as an effective ingredient.
Hereinafter, the present invention will be described in more detail.
The method for preparing a polymeric microsphere of the present invention may include (a) preparing an oil-in-water (O/W), oil-in-oil (O/O) or water-in-oil-in-water (W/O/W) emulsion including a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent; and
(b) adding to the emulsion prepared in (a) a base solution or an acid solution to remove the water-insoluble organic solvent from the emulsion.
Each step of the method for producing polymeric microspheres according to the present invention will be described in detail as follows.
(a): Preparation of emulsion
An oil-in-water (O/W), oil-in-oil (O/O) or water-in-oil-in-water (W/O/W) emulsion comprising a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent is prepared.
The emulsion may be prepared by a method commonly used in the art. More specifically, in order to prepare an oil-in-water (O/W) type or oil-in-oil (O/O) type emulsion, a dispersed phase comprising a polymer compound, a drug and a water-insoluble organic solvent is added to a dispersion solvent. And, in order to prepare a water-in-oil-in-water (W/O/W) emulsion, an aqueous solution in which a drug is dissolved, is emulsified in a water-insoluble organic solvent in which a polymer compound is dissolved, so as to form a W/O (water-in-oil) type emulsion, and then added to the dispersion solvent to produce a W/O/W (water-in-oil-in-water) type emulsion.
The polymer compound for preparing the polymeric microsphere may be used without limitation if it is well known in the art, however, preferably, it may be polylactic acid, polylactide, polylactic-co-glycolic acid, polylactide-co-glycolide(PLGA), polyphosphazine, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, a copolymer of lactic acid and caprolactone, polycaprolactone, polyhydroxyvalerate, polyhydroxybutyrate, polyamino acid, a copolymer of lactic acid and amino acid, and a mixture thereof.
The drug used in the present invention may include all of hydrophilic drugs and hydrophobic drugs and it may be used without limitation if it is able to be encapsulated to polymeric microshperes. Examples of the drug include progesterone, haloperidol, thiothixene, olanzapine, clozapine, bromperidol, pimozide, risperidone, ziprasidone, diazepma, ethyl loflazepate, alprazolam, nemonapride, fluoxetine, sertraline, venlafaxine, donepezil, tacrine, galantamine, rivastigmine, selegiline, ropinirole, pergolide, trihexyphenidyl, bromocriptine, benztropine, colchicine, nordazepam, etizolam, bromazepam, clotiazepam, mexazolum, buspirone, goserelin acetate, somatotropin, leuprolide acetate, octreotide, cetrorelix, sandostatin acetate, gonadotropin, fluconazole, itraconazole, mizoribine, cyclosporin, tacrolimus, naloxone, naltrexone, cladribine, chlorambucil, tretinoin, carmusitne, anagrelide, doxorubicin, anastrozole, idarubicin, cisplatin, dactinomycin, docetaxel, paclitaxel, raltitrexed, epirubicin, letrozole, mefloquine, primaquine, oxybutynin, tolterodine, allylestrenol, lovostatin, simvastatin, provastatin, atrovastatin, alendronate, salcatonin, raloxifene, oxadrolone, conjugated estrogen, estradiol, estradiol valerate, estradiol benzoate, ethinyl estradiol, etonogestrel, levonorgestrel, tibolone, norethisterone and piroxicam and it also may be macro molecules such as proteins or nucleic acid.
The water-insoluble organic solvent used in the present invention may be used without limitation if it is well known in the art, as long as it is capable of dissolving the polymer which is used for the preparation of the polymeric microspheres, being hydrolyzed by an acid or a base, and being hydrolyzed into water-soluble products. In general, compounds having backbone of amide, ester, anhydride and halogen acid are known to be easily hydrolyzed by an acid or a base.
Compounds having backbone of anhydride are hydrolyzed to produce water-soluble carboxylic acids, and compounds having backbone of ester are hydrolyzed into carboxylic acid and alcohol. Compounds having backbone of acid halogen are hydrolyzed into carboxylic acid and halogen acid(HF, HCl, Hbr, HI etc). Since compounds having backbone of amide are hydrolyzed into carboxylic acid and amine, if the produced amine is water-soluble, the corresponding amide may be included in the water-insoluble organic solvent of the present invention.
The water-insoluble organic solvent of the present invention may be compounds having backbone of acid halogen, compounds having backbone of anhydride, compounds having backbone of phosphoric anhydride, compounds having backbone of ester, compounds having backbone of carboxylic esters, compounds having backbone of phosphoric esters, compounds having backbone of sulfuric acid esters, compounds having backbone of nitric esters, compounds having backbone of boric acid, compounds having backbone of amide and compounds having backbone of carboxylic amides, preferably, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl formate, ethyl formate, isopropyl formate, propyl formate, butyl formate, methyl dichloroacetate, methyl chloroacetate, ethyl chloroacetate, ethyl dichloroacetate, methyl fluoroacetate, methyl difluoroacetate, ethyl fluoroacetate, ethyl difluoroacetate, maleic anhydride, acetic anhydride, propionic anhydride, phosphoric anhydride, acetamide, propionamide, butylamide and carboxyl amide.
More specifically, it is preferable that the water-insoluble organic solvent is selected from the group consisting of ethyl acetate, methyl acetate, methyl formate, ethyl formate, isopropyl formate, propyl formate, acetic anhydride or propionic anhydride.
Further, if necessary, the water-insoluble organic solvent may control solubility of the drug to be encapsulated in the microsphere or control the hardening speed of the emulsion droplet, as desired, by using a co-solvent prepared by mixing one or more different organic solvents.
The dispersion solvent used in the present invention includes an aqueous dispersion solvent containing an emulsifier or non-aqueous dispersion solvent, and the aqueous dispersion solvent is used for the preparation of an O/W type and W/O/W type emulsion, the non-aqueous dispersion solvent is used for the preparation of an O/O type emulsion. As the aqueous dispersion solvent, an aqueous solution containing hydrophilic emulsifier such as polyvinyl alcohol or polysorbates (for example, polysorbate 20, polysorbate 60, polysorbate 65, polysobate 80, polysorbate 85) or a co-solvent thereof can be used. As the non-aqueous dispersion solvent, silicone oil, vegetable oil, toluene, or xylene containing lipophilic emulsifier such as glycerin esters of fatty acids or lecithin can be used. The concentration of the emulsifier in the dispersion solvent may be 0.05 to 15% (w/v).
The polymer may be included in an amount of 1 to 500 parts by weight, preferably 1 to 50 parts by weight, based on 1 part by weight of the drug. The concentration of the polymer in the emulsion may be 3 to 30 % (w/v).
The volume ratio of the dispersed phase or the W/O (water-in-oil) type emulsion to the dispersion solvent may be 1:1-100, preferably 1:3-15. And, the volume ratio of the aqueous solution in which the drug is dissolved, to the water-insoluble organic solvent in which the polymer is dissolved, may be 1:1-50, preferably 1:2-20.
(b): Removal of water-insoluble organic solvent from emulsion
A base or an acid solution is added to the O/W, W/O/W or O/O emulsion prepared in (a) to remove the water-insoluble organic solvent from the emulsion.
In the present invention, the removal of the water-insoluble organic solvent from the emulsion by adding a base or acid solution is preferably accomplished by hydrolysis. Hydrolysis refers to a reaction which is decomposed into two products by adding water. Compounds having backbone of ester are hydrolyzed into carboxylic acid and alcohol, compounds having backbone of anhydride are hydrolyzed into carboxylic acids, compounds having backbone of amide are hydrolyzed into carboxylic acid and amine and compounds having backbone of acid halogen are hydrolyzed into carboxylic acid and halogen acid (such as HF, HCl, HBr, HI). Through this reaction, the water-insoluble organic solvent diffused (or dissolved) in small quantity in a layer (e.g., an aqueous layer (water phase)) is converted into a water-soluble organic solvent which is completely dissolved in water, and the water-insoluble organic solvent is diffused into the aqueous layer by that amount. As this process continues, the water-insoluble organic solvent is removed from the emulsion, thereby resulting in hardening of the emulsion droplet into a microsphere. As a result, a desired polymer microsphere including the drug can be prepared. The removal of the water-insoluble organic solvent from the emulsion includes, in addition to complete or substantial (to an extent not to be detected) removal of the water-insoluble organic solvent, reduction of the amount of the water-insoluble organic solvent as compared to before the addition of the acid or base. As the emulsion droplet is quickly hardened, the interaction between the emulsion droplet particles may be reduced and the desired microsphere may be obtained without coalescence. The acid catalyzes the reaction and the base is consumed during the reaction. If amount of the acid or base be added in less molar or more molar than that of the water-insoluble organic solvent, the reaction can always occur. However, since addition of too much acid or base may induce problem with respect to the stability of the drug and the polymer, a suitable amount thereof have to be considered. Preferably, the base solution may be added in such an amount that the molar ratio of the water-insoluble organic solvent to the base solution is 1:0.1-10, more preferably 1:0.1-5, further more preferably 1:0.2-3, the most preferably 1:0.2-1.5.
Preferably, the base may be NaOH, LiOH, KOH, NH4OH, Cu(OH)2 and Fe(OH)3, and the acid may be HCl, HNO3, H2SO4, CH3COOH, H3BO3 and H2CO3. In the description, the base or acid is also referred to as a decomposition reagent.
The polymeric microsphere prepared by the method of the present invention has an average particle size of 0.1 to 3500 ㎛, preferably 10 to 350 ㎛, and may comprise a variety amount of drug, as required.
According to the method of the present invention, a drug-containing polymeric microsphere may be prepared quickly and simply without the solvent evaporation or solvent extraction process, thereby reducing water consumption and minimizing wastewater generation.
The polymer microsphere of the present invention is capable of effectively delivering the drug included in the polymer microsphere. Therefore, the present invention provides a composition for drug delivery comprising the polymer microsphere prepared by the preparation method of the present invention as an effective ingredient.
As will be easily understood by those skilled in the art, the composition for drug delivery of the present invention may be applied to various diseases depending on the drug included therein.
The nucleotide or protein processing may be referred to the following literature [Maniatis et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1982); Sambrook et al., Molecular Cloning: A Laboratory Manual, 2d Ed., Cold Spring Harbor Laboratory Press (1989); Deutscher, M., Guide to Protein Purification Methods Enzymology, vol. 182. Academic Press. Inc., San Diego, CA (1990)].
In an example, GC analysis was carried out in order to investigate whether ethyl acetate, ethyl formate, propyl formate, and isopropyl formate are decomposed by an acid or base in an aqueous phase. When no reagent was added to the aqueous phase (blank), some of ethyl acetate, ethyl formate, propyl formate or isopropyl formate was transported into the aqueous phase, thereby increasing their concentration in the aqueous phase until saturation. When their concentration is saturated, their transportation into the aqueous phase does not occur. In contrast, when the acid or base was added, hydrolysis continued to occur, thereby increasing the concentration of the hydrolyzed product such as ethanol continuously.
In another example, it was investigated whether propionic anhydride is hydrolyzed by an acid or a base and is dissolved in the aqueous phase. When no acid or base was added, propionic anhydride mixed with 0.5% polyvinyl alcohol maintained an emulsion state. In contrast, when an acid or a base was added, the emulsion disappeared and a clear and transparent single phase appeared.
In another example, it was demonstrated that, when isopropyl formate is used and a base is used as a decomposition reagent, emulsion droplets can be quickly hardened to form microspheres by adding various amounts of the decomposition reagent to the aqueous phase. In contrast, when no decomposition reagent is added to the aqueous phase, the emulsion droplets were not hardened to form microspheres. Therefore, it can be seen that using of the decomposition reagent is important for the preparation of microspheres.
In another example, progesterone, anastrazole, olanzapine, risperidone, aripiprazole, docetaxel, piroxicam, rivastigmine or tolterodine was selected as target drugs, and microparticles in which the target drugs are encapsulated were prepared at various conditions. And it was observed that their properties, encapsulation ratio, residual amount of organic solvent, or the like. As a result, spherical microparticles encapsulating the target drug were prepared well, and they had high encapsulation ratio. Besides, the residual amount of organic solvent was very low level.
Hereunder is given a description about the attached drawings.
Fig. 1 shows gas chromatography (GC) chromatograms of an aqueous phase sample depending on time of an ethyl acetate/aqueous phase system following slow stirring. Each chromatogram is for the case where no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M NaOH was added (EA = ethyl acetate, IS = internal standard, EtOH = ethanol).
Fig. 2 shows a change of ethanol and ethyl acetate concentrations in the aqueous phase depending on time. (A) Ethanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M NaOH was added. (B) Ethyl acetate concentration in the aqueous phase when no NaOH was added, and 2 mL or 5 mL of 10 M NaOH was added.
Fig. 3 shows GC chromatograms of an aqueous phase sample depending on time of an ethyl formate/aqueous phase system following slow stirring. Each chromatogram is for the case where no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M NaOH was added (EF = ethyl formate, IS = internal standard, EtOH = ethanol).
Fig. 4 shows GC chromatograms of an aqueous phase sample depending on time of an ethyl formate/aqueous phase system following slow stirring. Each chromatogram is for the case where no decomposition reagent was added to the aqueous phase, and 2 mL or 6 mL of 10 M HCl was added (EF = ethyl formate, IS = internal standard, EtOH = ethanol).
Fig. 5 shows a change of ethanol concentration in the aqueous phase depending on time. (A) Ethanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M NaOH was added. (B) Ethanol concentration in the aqueous phase when 2 mL or 6 mL of 10 M HCl was added.
Fig. 6 shows GC chromatograms of an aqueous phase sample depending on time of a propyl formate/aqueous phase system following slow stirring. Each chromatogram is for the case where no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M NaOH was added (PF = propyl formate, IS = internal standard, PrOH = propanol).
Fig. 7 shows a change of propanol/propyl formate concentrations in the aqueous phase depending on time. (A) Propanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M NaOH was added. (B) Propyl formate concentration in the aqueous phase when no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M NaOH was added.
Fig. 8 shows GC chromatograms of an aqueous phase sample depending on time of a propyl formate/aqueous phase system following slow stirring. Each chromatogram is for the case where no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M HCl was added (PF = propyl formate, IS = internal standard, PrOH = propanol).
Fig. 9 shows a change of propanol/propyl formate concentrations in the aqueous phase depending on time. (A) Propanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M HCl was added. (B) Propyl formate concentration in the aqueous phase when no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M HCl was added.
Fig. 10 shows GC chromatograms of an aqueous phase sample depending on time of an isopropyl formate/aqueous phase system following slow stirring. Each chromatogram is for the case where no decomposition reagent was added to the aqueous phase, and 2 mL or 5 mL of 10 M NaOH was added (IF = isopropyl formate, IS = internal standard).
Fig. 11 shows a change of isopropanol/isopropyl formate concentrations in the aqueous phase depending on time. (A) Isopropanol concentration in the aqueous phase when 2 mL or 5 mL of 10 M NaOH was added. (B) Isopropyl formate concentration in the aqueous phase when no decomposition reagent was added to the aqueous phase, and 2 mL or 6 mL of 10 M HCl was added.
Fig. 12 shows GC chromatograms of an aqueous phase sample depending on time of an isopropyl formate/aqueous phase system following slow stirring. Each chromatogram is for the case where 2 mL or 5 mL of 10 M HCl was added to the aqueous phase (IF = isopropyl formate, IS = internal standard).
Fig. 13 shows a change of isopropanol concentration in the aqueous phase. It shows that, when 2 mL or 5 mL of 10 M HCl was added, isopropyl formate was decomposed and changed into isopropanol.
Fig. 14 shows a change of emulsion depending on time when a propionic anhydride/aqueous phase system (A) is stirred without adding an acid or base, (B) is stirred after adding 2 mL of strong HCl, and (C) is stirred after adding 3 mL of 10 M NaOH. When no acid or base was added, two phases were maintained. In contrast, when the acid (B) or the base (C) was added, the emulsion disappeared and a clear and transparent single phase appeared.
Fig. 15 shows light micrographs of 7E microparticles prepared by using isopropyl formate as an organic solvent and using NaOH at various concentrations as a decomposition reagent. (A): NaOH was not added (0 mL). (B)-(F): 1, 2, 3, 4 and 5 mL of 10 M NaOH was added, respectively. When NaOH was not added, the emulsion droplets coalesced to form a polymeric film.
Fig. 16 shows electron micrographs of 7E microparticles prepared by using NaOH as an ethyl acetate decomposition reagent. (a), (c): Inside and outside of the microparticles prepared by using 60 mg of progesterone. (b), (d): Inside and outside of the microparticles prepared by using 250 mg of progesterone.
Fig. 17 shows electron micrographs of 7E microparticles prepared by using NaOH as an ethyl formate decomposition reagent. (a), (c): Inside and outside of the microparticles prepared by using 60 mg of progesterone. (b), (d): Inside and outside of the microparticles prepared by using 250 mg of progesterone.
Fig. 18 shows electron micrographs of microparticles prepared by using 0.25 g of 4A PLGA and NaOH as an ethyl acetate decomposition reagent. (a), (c): Inside and outside of the microparticles prepared by using 60 mg of progesterone. (b), (d): Inside and outside of the microparticles prepared by using 250 mg of progesterone.
Fig. 19 shows electron micrographs of microparticles prepared by using 0.25 g of 4A PLGA and NaOH as an ethyl formate decomposition reagent. (a), (c): Inside and outside of the microparticles prepared by using 60 mg of progesterone. (b), (d): Inside and outside of the microparticles prepared by using 250 mg of progesterone.
Fig. 20 shows electron micrographs showing outside of microparticles prepared by using 10 M NaOH as an isopropyl formate decomposition reagent. In (a), (b), (c), (d), (e) and (f), 0, 60, 100, 160, 200 and 250 mg of progesterone was used, respectively.
Fig. 21 shows electron micrographs showing inside of microparticles prepared by using 10 M NaOH as an isopropyl formate decomposition reagent. In (a), (b), (c), (d), (e) and (f), 0, 60, 100, 160, 200 and 250 mg of progesterone was used, respectively.
Fig. 22 shows electron micrographs of microparticles prepared by using propyl formate as an organic solvent and 2 mL of HCl as a decomposition reagent. (a): Microparticles prepared by using 0.25 g of 7E polymer only. (b): Microparticles prepared by using 0.25 g of 7E polymer and 250 mg of progesterone.
Fig. 23 shows a thermogravimetric analysis result of microparticle samples. It can be seen that the amount of the volatile residual organic solvent is extremely slight in the microparticles comprising progesterone, and is smaller than that of the microparticles not containing progesterone.
Fig. 24 shows electron micrographs of microparticles prepared by using 60 mg of anastrazole, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl acetate decomposition reagent.
Fig. 25 shows electron micrographs of microparticles prepared by using 60 mg of anastrazole, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl formate decomposition reagent.
Fig. 26 shows HPLC chromatograms of various samples under an anastrazole encapsulation ratio analysis condition. (a): Mixture solution of tetrahydrofuran and 50% acetonitrile aqueous solution. (b): Solution prepared by spiking ethyl acetate in sample (a). (c): Filtrate by an experimental condition of blank microparticles not containing drug. (d) Filtrate by an experimental condition of microparticles containing anastrazole. (e): Anastrazole standard solution prepared by using 50% acetonitrile aqueous solution. It can be seen that a very small amount of ethyl acetate is detected from the two microparticle samples and no anastrazole modification product is detected.
Fig. 27 shows electron micrographs of microparticles prepared by using 60 mg of olanzapine, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl acetate decomposition reagent.
Fig. 28 shows electron micrographs of microparticles prepared by using 60 mg of risperidone, 0.25 g of 4A and NaOH as an ethyl formate decomposition reagent.
Fig. 29 shows electron micrographs of microparticles prepared by using 40 mg of aripiprazole, 0.25 g of 4A and NaOH as an ethyl formate decomposition reagent.
The present invention provides a novel method for preparing a polymeric microsphere comprising the step of removing a water-insoluble organic solvent using a base or an acid, a polymeric microsphere prepared by the method, and a composition for drug delivery comprising the polymeric microsphere. According to the present invention, a drug-containing polymer microsphere may be prepared quickly and simply without the solvent evaporation or solvent extraction process, thereby reducing water consumption and minimizing wastewater generation.
Fig. 1 shows gas chromatography (GC) chromatograms of an aqueous phase sample depending on time of an ethyl acetate/aqueous phase system following slow stirring.
Fig. 2 shows a change of ethanol and ethyl acetate concentrations in the aqueous phase depending on time.
Fig. 3 shows GC chromatograms of an aqueous phase sample depending on time of an ethyl formate/aqueous phase system following slow stirring.
Fig. 4 shows GC chromatograms of an aqueous phase sample depending on time of an ethyl formate/aqueous phase system following slow stirring.
Fig. 5 shows a change of ethanol concentration in the aqueous phase depending on time.
Fig. 6 shows GC chromatograms of an aqueous phase sample depending on time of a propyl formate/aqueous phase system following slow stirring.
Fig. 7 shows a change of propanol/propyl formate concentrations in the aqueous phase depending on time.
Fig. 8 shows GC chromatograms of an aqueous phase sample depending on time of a propyl formate/aqueous phase system following slow stirring.
Fig. 9 shows a change of propanol/propyl formate concentrations in the aqueous phase depending on time.
Fig. 10 shows GC chromatograms of an aqueous phase sample depending on time of an isopropyl formate/aqueous phase system following slow stirring.
Fig. 11 shows a change of isopropanol/isopropyl formate concentrations in the aqueous phase depending on time.
Fig. 12 shows GC chromatograms of an aqueous phase sample depending on time of an isopropyl formate/aqueous phase system following slow stirring.
Fig. 13 shows a change of isopropanol concentration in the aqueous phase depending on time.
Fig. 14 shows a change of emulsion depending on time when a propionic anhydride/aqueous phase system (A) is stirred without adding an acid or base, (B) is stirred after adding 2 mL of strong HCl, and (C) is stirred after adding 3 mL of 10 M NaOH.
Fig. 15 shows light micrographs of 7E microparticles prepared by using isopropyl formate as an organic solvent and using NaOH at various concentrations as a decomposition reagent. (A): NaOH was not added (0 mL). (B)-(F): 1, 2, 3, 4 and 5 mL of 10 M NaOH was added, respectively.
Fig. 16 shows electron micrographs of 7E microparticles prepared by using NaOH as an ethyl acetate decomposition reagent.
Fig. 17 shows electron micrographs of 7E microparticles prepared by using NaOH as an ethyl formate decomposition reagent.
Fig. 18 shows electron micrographs of microparticles prepared by using 0.25 g of 4A PLGA and NaOH as an ethyl acetate decomposition reagent.
Fig. 19 shows electron micrographs of microparticles prepared by using 0.25 g of 4A PLGA and NaOH as an ethyl formate decomposition reagent.
Fig. 20 shows electron micrographs showing outside of microparticles prepared by using 10 M NaOH as an isopropyl formate decomposition reagent.
Fig. 21 shows electron micrographs showing inside of microparticles prepared by using 10 M NaOH as an isopropyl formate decomposition reagent.
Fig. 22 shows electron micrographs of microparticles prepared by using propyl formate as an organic solvent and 2 mL of HCl as a decomposition reagent.
Fig. 23 shows a thermogravimetric analysis result of microparticle samples.
Fig. 24 shows electron micrographs of microparticles prepared by using 60 mg of anastrazole, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl acetate decomposition reagent.
Fig. 25 shows electron micrographs of microparticles prepared by using 60 mg of anastrazole, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl formate decomposition reagent.
Fig. 26 shows HPLC chromatograms of various samples under an anastrazole encapsulation ratio analysis condition.
Fig. 27 shows electron micrographs of microparticles prepared by using 60 mg of olanzapine, 0.15 g of 7E, 0.1 g of 4A and NaOH as an ethyl acetate decomposition reagent.
Fig. 28 shows electron micrographs of microparticles prepared by using 60 mg of risperidone, 0.25 g of 4A and NaOH as an ethyl acetate decomposition reagent.
Fig. 29 shows electron micrographs of microparticles prepared by using 40 mg of aripiprazole, 0.25 g of 4A and NaOH as an ethyl acetate decomposition reagent.
The examples will now be described.
The following examples are for illustrative purposes only and not intended to limit the scope of the present invention.
<Example 1>
Removal of organic solvent (ethyl acetate) using acid or base
It was investigated whether ethyl acetate is decomposed and removed by an acid or a base. When ethyl acetate is decomposed by an acid or a base, water-soluble ethanol and acetic acid are produced. Therefore, concentrations of ethyl acetate and ethanol in the aqueous solution were quantitated by gas chromatography (GC).
40 mL of 0.5% polyvinyl alcohol (PVA) aqueous solution was added to a beaker. After adding 2 mL or 5 mL of 10 M NaOH or 10 M HCl (0 mL for the blank), 4 mL of ethyl acetate was added along the wall. While stirring such that the two phases are not completely mixed, each 200 of sample was taken from the aqueous phase at 3, 15, 25, 35, 45, 60 and 75 minutes for GC analysis.
GC analysis was performed with GC-2010 (Shimadzu, Japan). Zebron ZB-624 (Phenomenex, USA)analysis column using 6%-cyanopropylphenyl-94%-methylpolysiloxane as stationary phase was used. The quantity of ethyl acetate, and ethanol which is the decomposition products of ethyl acetate, was measured using isopropanol as internal standard.
As seen in Fig. 1 and Fig. 2, when no reagent was added to the aqueous phase (blank), some of ethyl acetate was changed to the aqueous phase with time. Its concentration in the aqueous phase increased until it reached a constant value. This means that ethyl acetate was saturated in the aqueous phase. In addition, ethanol was not detected at all in the aqueous phase because ethyl acetate was not decomposed.
In contrast, when 5 mL of 10 M NaOH was added, the concentration of ethanol, which is the hydrolysis product of ethyl acetate, continued to increase. This is because ethanol and sodium acetate are produced as ethyl acetate is hydrolyzed. Further, ethyl acetate dissolved in the aqueous phase was not detected because it was quickly decomposed by NaOH. Upon completion of the reaction, the two phases were completely mixed into one phase.
When 2 mL of 10 M NaOH was added, initially, ethanol was produced as ethyl acetate was decomposed. However, when NaOH was consumed after time passed, ethanol did not increase any more and ethyl acetate dissolved in the aqueous phase was detected.
<Example 2>
Removal of organic solvent (ethyl formate) using acid or base
It was investigated whether ethyl formate is decomposed and removed by an acid or a base. When ethyl formate is decomposed by an acid or a base, water-soluble ethanol and formic acid are produced. Therefore, concentrations of ethyl formate and ethanol in the aqueous solution were quantitated by gas chromatography (GC).
40 mL of 0.5% polyvinyl alcohol(PVA) aqueous solution was added to a beaker. After adding 2 mL or 6 mL of 10 M NaOH or 10 M HCl (0 mL for the blank), 4 mL of ethyl formate was added along the wall. Stirring was performed such that the two phases are not completely mixed, so that some of ethyl formate diffused into the aqueous phase. Each 200 of sample was taken from the aqueous phase at 5, 10, 15, 20, 30, 45 and 60 minutes for GC analysis.
GC analysis was performed with GC-2010 (Shimadzu, Japan). Zebron ZB-624 (Phenomenex, USA) analysis column using 6%-cyanopropylphenyl-94%-methylpolysiloxane as stationary phase was used. The quantity of ethyl formate, and ethanol which is the decomposition products of ethyl formate, was measured using methanol as internal standard.
As seen in Fig. 3 and Fig. 4, when no reagent was added to the aqueous phase, some of ethyl formate was changed into the aqueous phase with time. Its concentration in the aqueous phase increased until it reached a constant value. This means that ethyl formate was saturated in the aqueous phase. In addition, ethanol was not detected at all in the aqueous phase because ethyl formate was not decomposed.
In contrast, when 6 mL of 10 M NaOH was added, the concentration of ethanol, which is the hydrolysis product of ethyl formate, continued to increase. This is because ethanol and sodium formate are produced as ethyl formate is hydrolyzed. Further, ethyl formate dissolved in the aqueous phase was not detected because it was quickly decomposed by NaOH. Upon completion of the reaction, the two phases were completely mixed into one phase.
When 2 mL of 10 M NaOH was added, initially, ethanol was produced as ethyl formate was decomposed. However, as time passed and NaOH was consumed, ethanol did not increase any more and ethyl formate dissolved in the aqueous phase was detected.
When 10 M HCl was used as an ethyl formate decomposition reagent instead of 10M NaOH, as seen in Fig. 4 and Fig. 5B, ethyl formate was effectively decomposed in both cases where 6 mL and 2 mL of HCl were used when the reaction time is prolonged. This is because, whereas NaOH is consumed during the reaction, HCl acts as a catalyst without being consumed.
<Example 3>
Removal of organic solvent (propyl formate) using acid or base
It was investigated whether propyl formate is decomposed and removed by an acid or a base. When ethyl formate is decomposed by an acid or a base, water-soluble propanol and formic acid are produced. Therefore, concentrations of propyl formate and propanol in the aqueous solution were quantitated by gas chromatography (GC).
40 mL of 0.5% polyvinyl alcohol(PVA) aqueous solution was added to a beaker. After adding 2 mL or 6 mL of 10 M NaOH or 10 M HCl (0 mL for the blank), 4 mL of propyl formate was added along the wall. Stirring was performed such that the two phases are not completely mixed, so that some of ethyl formate diffused into the aqueous phase. Each 200 of sample was taken from the aqueous phase at 5, 10, 15, 20, 30, 45, 60, 85, 120 and 160 minutes for GC analysis.
GC analysis was performed with GC-2010 (Shimadzu, Japan). Zebron ZB-624 (Phenomenex, USA) analysis column using 6%-cyanopropylphenyl-94%-methylpolysiloxane as stationary phase was used. The quantity of propyl formate, and propanol which is the decomposition products of propyl formate, was measured using ethanol as internal standard.
As seen in Fig. 6 and Fig. 7, when no reagent was added to the aqueous phase, some of propyl formate was transported into the aqueous phase with time. Its concentration in the aqueous phase increased until it reached a constant value. This means that propyl formate was saturated in the aqueous phase. In addition, propanol was not detected at all in the aqueous phase because propyl formate was not decomposed.
In contrast, when 5 mL of 10 M NaOH was added, the concentration of propanol, which is the hydrolysis product of propyl formate, continued to increase. This is because propanol and sodium formate are produced as propyl formate is hydrolyzed. Further, propyl formate dissolved in the aqueous phase was not detected because it was quickly decomposed by NaOH. Upon completion of the reaction, the two phases were completely mixed into one phase.
When 2 mL of 10 M NaOH was added, initially, ethanol was produced as propyl formate was decomposed. However, as time passed and NaOH was consumed, propanol did not increase any more and propyl formate dissolved in the aqueous phase was detected.
When 10 M HCl was used as a propyl formate decomposition reagent instead of 10 M NaOH, as seen in Fig. 8 and Fig. 9, propyl formate was effectively decomposed in both cases where 6 mL and 2 mL of HCl was used when the reaction time is prolonged. This is because, whereas NaOH is consumed during the reaction, HCl acts as a catalyst without being consumed.
<Example 4>
Removal of organic solvent (isopropyl formate) using acid or base
It was investigated whether isopropyl formate is decomposed and removed by an acid or a base. When isopropyl formate is decomposed by an acid or a base, water-soluble isopropanol and formic acid are produced. Therefore, concentrations of isopropyl formate and isopropanol in the aqueous solution were quantitated by gas chromatography (GC).
40 mL of 0.5% polyvinyl alcohol aqueous solution was added to a beaker. After adding 2 mL or 5 mL of 10 M NaOH or 10 M HCl (0mL for the blank), 4 mL of isopropyl formate was added. While stirring such that the two phases are not completely mixed, so each 200 of sample was taken from the aqueous phase at 3, 15, 25, 35, 45, 60, 75, 90, 120, 150 and 180 minutes for GC analysis.
GC analysis was performed with GC-2010 (Shimadzu, Japan). Zebron ZB-624 (Phenomenex, USA) analysis column using 6%-cyanopropylphenyl-94%-methylpolysiloxane as stationary phase was used. The quantity of isopropyl formate, and isopropanol which is the decomposition products of isopropyl formate, was measured using ethanol as internal standard.
As seen in Fig. 10 and Fig. 11, when no reagent was added to the aqueous phase, some of isopropyl formate was transferred to the aqueous phase with time. Its concentration increased until it reached a constant value. This means that isopropyl formate was saturated in the aqueous phase. In addition, isopropanol was not detected at all in the aqueous phase because isopropyl formate was not decomposed.
In contrast, when 5 mL of 10 M NaOH was added, the concentration of isopropanol, which is the hydrolysis product of isopropyl formate, continued to increase. This is because isopropanol and sodium formate are produced as isopropyl formate is hydrolyzed. Further, isopropyl formate dissolved in the aqueous phase was not detected because it was quickly decomposed by NaOH. Upon completion of the reaction, the two phases were completely mixed into one phase.
When 2 mL of 10 M NaOH was added, initially, ethanol was produced as isopropyl formate was decomposed. However, as time passed and NaOH was consumed, isopropanol did not increase any more and isopropyl formate dissolved in the aqueous phase was detected.
When 10 M HCl was used as a isopropyl formate decomposition reagent instead of 10 M NaOH, as seen in Fig. 12 and Fig. 13, isopropyl formate was effectively decomposed in both the cases where 6 mL and 2 mL of HCl was used when the reaction time is prolonged. This is because, whereas NaOH is consumed during the reaction, HCl acts as a catalyst without being consumed.
<Example 5>
Removal of organic solvent (propionic anhydride) using acid or base
It was investigated whether propionic anhydride is hydrolyzed by an acid or a base. When propionic anhydride is decomposed by an acid or a base, water-soluble propionic acid is produced. Therefore, we confirmed whether the initial two phases were completely mixed into one phase upon completion of the reaction.
40 mL of 0.5% polyvinyl alcohol aqueous solution was added to a beaker. After adding 3 mL of 10 M NaOH (or 2 mL of strong HCl), the stirring speed of the stirrer was set at 550 rpm. After adding 4mL of propionic anhydride, change of phase was observed with time. For control experiment, 4 mL of propionic anhydride was emulsified in 40 mL of 0.5% polyvinyl alcohol aqueous solution without adding NaOH or HCl, and change of phase was observed.
As seen in Fig. 14, when an acid or a base was not added, the hazy emulsion state (actually, two phases) was maintained even after stirring for 20 minutes. This means that the aqueous phase is quickly saturated with some of the propionic anhydride, and the remaining propionic anhydride persists in the emulsion droplets. However, when an acid or a base was added, the emulsion disappeared within 20 minutes and a clear and transparent single phase appeared. This result shows that the water-insoluble propionic anhydride was completely converted into water-soluble propionic acid through acid/base reaction.
<Example 6>
Hardening of microparticles depending on the amount of organic solvent decomposition reagent
The polymer used Example 6 to Example 12 in the present invention is poly-d,l-lactide-co-glycolide(PLGA), specifically, PLGA 75:25 (i.v. = 0.70 dL/g in CHCl3, its abbreviation refers to 7E), PLGA 50:50(i.v. = 0.46 dL/g in CHCl3, its abbreviation refers to 4A), and PLGA 50:50(i.v. = 0.18 dL/g in CHCl3, its abbreviation refers to 2A).
0.25 g of 7E was completely dissolved in 4 mL of isopropyl formate. The resultant dispersed phase was added to a beaker containing 40 mL of 0.5% polyvinyl alcohol aqueous solution and emulsified by stirrer. The resultant emulsion was stirred for 3 minutes and, after adding 0, 1, 2, 3, 4 and 5 mL of 10 M NaOH, further stirred for 15 minutes. Then, some of the sample was taken and observed on a glass slide using an optical microscope.
As seen in Fig. 15, when isopropyl formate was used as an organic solvent, the emulsion droplets remained in the liquid state for 15 minutes when no NaOH was used. Therefore, when stirring was stopped and the sample was placed on the glass slide for optical microscope imaging, the emulsion droplets coalesced into film-shaped aggregates, not microparticles. In contrast, when 1 mL of 10M NaOH was added, the emulsion droplets did not coalesce. Similarly, when 2 mL to 5 mL of NaOH were added, the coalescence of the emulsion droplets could be effectively prevented.
<Example 7>
Preparation of microparticles encapsulating progesterone
<7-1> Preparation of microparticles encapsulating progesterone using ethyl acetate or ethyl formate
0.25 g of 7E or 4A was dissolved in 4 mL of ethyl acetate. After adding and dissolving progesterone (60 or 250 mg) therein, the resultant dispersed phase was added to 40 mL of 0.5% polyvinyl alcohol (PVA) aqueous solution and stirred to prepare an oil-in-water (o/w) emulsion. After adding 5 mL of 10 M NaOH to the emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was added. After stirring and filtration, microparticles were recovered. The microparticles were redispersed in 16 mL of 0.5% PVA solution and stirred, after adding distilled water to make 80 mL. After filtration, the microparticles were dried overnight in a vacuum dryer.
Similarly, microparticles encapsulating progesterone were prepared using ethyl formate instead of ethyl acetate and using 6 mL of 10 M NaOH or 5 mL of 10 M HCl as a decomposition reagent.
As seen in Fig. 16, Fig. 17, Fig. 18 and Fig. 19, microspheres encapsulating progesterone were prepared well. When ethyl acetate or ethyl formate was used as an organic solvent, inside and outside shapes of the microparticles were similar.
<7-2> Measurement of progesterone encapsulation ratio
Some of the microparticles prepared in Example <7-1> were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with methanol, the solution was filtered to remove the PLGA precipitate. Some of the filtrate (20 ㎕) was subjected to HPLC (Shimadzu LC-20AD, Luna 5 m C18(2) column) for measurement of progesterone concentration. Theoretical drug load (%) and actual drug load (%) were calculated from the following equations, and their ratio was defined as drug encapsulation ratio (%).
Theoretical drug load (%) = (Weight of drug used (mg) / [Weight of PLGA used (mg) + Weight of drug used (mg)]) x 100
Actual drug load (%) = (Weight of drug encapsulated in microparticles (mg) / Weight of microparticles used for encapsulation ratio measurement (mg)) x 100
Drug encapsulation ratio (%) = (Actual drug load (%) / Theoretical drug load (%)) x 100
As seen in Table 1 (ethyl acetate) and Table 2 (ethyl formate), most of the added progesterone was encapsulated in the microparticles. The difference in the used organic solvent did not result in a significant difference of progesterone encapsulation ratio. When ethyl formate was used, similar encapsulation ratio was attained with 10 M NaOH and 10 M HCl. All the experiments exhibited batch reproducibility, with similar encapsulation ratios between batches.
Table 1
PLGA / quantity Progesterone(mg) Decomposition reagent Encapsulation ratio (%)
Batch 1 Batch 2 Batch 3
7E / 0.25g 60 10 M NaOH 5 mL 93.8 92.3 96.0
7E / 0.25g 250 10 M NaOH 5 mL 92.8 92.0 97.7
4A / 0.25g 60 10 M NaOH 5 mL 90.5 92.8 95.3
4A / 0.25g 250 10 M NaOH 5 mL 93.2 92.2 98.5
Table 2
PLGA / quantity Progesterone(mg) Decomposition reagent Encapsulation ratio (%)
Batch 1 Batch 2 Batch 3
7E / 0.25g 60 10 M NaOH 6 mL 93.9 94.0 91.6
7E / 0.25g 250 10 M NaOH 6 mL 95.5 98.5 99.7
4A / 0.25g 60 10 M NaOH 6 mL 92.0 93.3 95.6
4A / 0.25g 250 10 M NaOH 6 mL 96.2 93.2 100.7
7E / 0.25g 60 10 M HCl 5 mL 84.1 88.7 86.1
7E / 0.25g 100 10 M HCl 5 mL 89.0 92.8 91.5
7E / 0.25g 160 10 M HCl 5 mL 98.9 102.0 96.9
7E / 0.25g 200 10 M HCl 5 mL 99.2 102.0 95.5
7E / 0.25g 250 10 M HCl 5 mL 101.0 101.0 99.6
<7-3> Preparation of microparticles encapsulating progesterone using propyl formate or isopropyl formate
0.25 g of 7E was dissolved in 4 mL of isopropyl formate or propyl formate. After adding and dissolving progesterone (60 or 250 mg) therein, the resultant dispersed phase was added to 40 mL of 0.5% PVA aqueous solution and stirred to prepare an o/w emulsion. After adding 4 mL of 10 M NaOH to the emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was added. After stirring and filtration, microparticles were recovered. The microparticles were redispersed in 16 mL of 0.5% PVA solution and stirred, after adding distilled water to make 80 mL. After filtration, the microparticles were in a vacuum dryer.
As seen in Fig. 20, Fig. 21 and Fig. 22, when isopropyl formate or propyl formate were used, microspheres encapsulating progesterone were prepared well.
<7-4> Measurement of progesterone encapsulation ratio
Progesterone encapsulation ratio of the microparticles prepared in Example <7-3> was measured as in Example <7-2>.
As seen in Table 3 (propyl formate) and Table 4 (isopropyl formate), most of the added progesterone was encapsulated in the microparticles. The difference in the used organic solvent or the amount of progesterone did not result in a significant difference of progesterone encapsulation ratio.
Table 3
PLGA / quantity Progesterone (mg) Decomposition reagent Encapsulation ratio (%)
7E / 0.25g 60 10 M NaOH 4 mL 90.9 2.1
7E / 0.25g 100 10 M NaOH 4 mL 89.9 1.2
7E / 0.25g 160 10 M NaOH 4 mL 93.0 1.2
7E / 0.25g 200 10 M NaOH 4 mL 91.9 1.2
7E / 0.25g 250 10 M NaOH 4 mL 93.0 1.3
7E / 0.25g 60 10 M HCl 2 mL 83.5 0.9
7E / 0.25g 250 10 M HCl 2 mL 95.3 0.9
Table 4
PLGA / quantity Progesterone (mg) Decomposition reagent Encapsulation ratio (%)
7E / 0.25g 60 10 M NaOH 4 mL 94.6 2.4
7E / 0.25g 100 10 M NaOH 4 mL 92.4 2.0
7E / 0.25g 160 10 M NaOH 4 mL 95.4 0.9
7E / 0.25g 200 10 M NaOH 4 mL 96.1 0.9
250 10 M NaOH 4 mL 97.5 2.5
7E / 0.25g
7E / 0.25g 60 10 M HCl 2 mL 83.0 2.1
7E / 0.25g 250 10 M HCl 2 mL 92.0 2.6
<7-5> Measurement of organic solvent remaining in microparticles
The microparticles prepared using isopropyl formate as an organic solvent in Example <7-3> were stored for 3 days in vacuum state and the quantity of isopropyl formate remaining in the microparticle was measured.
The microparticles (about 30 mg) were accurately weighed and completely dissolved in 2 mL of methylene chloride. After diluting 5 times with butanol, the precipitated PLGA was removed by filtration. The concentration of isopropyl formate in the filtrate was measured by GC analysis in the same manner as in Example 4.
As seen in Table 5, the microparticles prepared in the present invention showed very low residual content of isopropyl formate. This demonstrates that the method for preparing microparticles according to the present invention is remarkably effective in removing the organic solvent since the isopropyl formate transferred from the emulsion droplets to the aqueous phase is effectively and continuously decomposed and removed. The residual content of the solvent was inversely proportional to the quantity of progesterone encapsulated in the microparticles.
Table 5
PLGA / quantity Progesterone (mg) Decomposition reagent Residual content (%)
7E / 0.25g 0 10 M NaOH 5mL 3.15 0.66
7E / 0.25g 60 10 M NaOH 5mL 1.57 0.46
7E / 0.25g 160 10 M NaOH 5mL 1.04 0.16
7E / 0.25g 250 10 M NaOH 5mL 0.62 0.07
<7-6> Thermogravimetric analysis of microparticles
The microparticles prepared in Example <7-3> (using isopropyl formate, 0.25 g of 7E and 250 mg of progesterone) and microparticles not including progesterone were analyzed using a thermogravimetric analyzer (TGA 2050). Nitrogen was used as a purge gas. Change in weight of the microparticles was automatically recorded while increasing temperature at a rate of 10 ℃/min.
As seen in Fig. 23, up to 150 ℃, where progesterone and the drug are considered not to be decomposed, weight loss of the microparticle sample not including progesterone was 3.74%. In contrast, up to 150 ℃, weight loss of the microparticles including 250 mg of progesterone was only 0.75%. This result shows a tendency similar to the measurement of the residual content of isopropyl formate using GC. To conclude, when microparticles are prepared according to the method of the present invention, the used organic solvent is effectively removed from the emulsion droplets and the amount of the organic solvent remaining in the microparticles is very slight.
<Example 8>
Preparation of microparticles encapsulating anastrazole
<8-1> Preparation of microparticles encapsulating anastrazole using ethyl acetate or ethyl formate
Each of 7E, 4A and 2A polymers was dissolved in 4 mL of ethyl acetate. Then, 60 mg of anastrazole was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. 5 mL of 10 M NaOH was added to the resultant o/w emulsion. After adding 40 mL of distilled water and stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
Similarly, microparticles encapsulating progesterone were prepared using ethyl formate instead of ethyl acetateand using 6 mL of 10 M NaOH.
As seen in Fig. 24 and Fig. 25, microspheres according to the method of the present invention were prepared well.
<8-2> Measurement of anastrazole encapsulation ratio
Some of the microparticles prepared in Example <8-1> were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with 50% acetonitrile, the solution was filtered using a 0.45 ㎛ syringe filter to remove the PLGA precipitate. Some of the filtrate (20 ㎕) was subjected to HPLC (Shimadzu LC-20AD, Luna 5 m C18(2) column) for measurement of anastrazole concentration. Drug encapsulation ratio (%) was calculated using the equations given in Example <7-2>.
As seen in Table 6, the microparticles according to the method of the present invention showed high encapsulation ratio and good batch reproducibility, with similar encapsulation ratios between batches. When ethyl formate was used, anastrazole encapsulation ratio was slightly lower than when ethyl acetate was used.
Table 6
PLGA / quantity Organic solvent Encapsulation ratio (%)
Batch 1 Batch 2 Batch 3
7E / 0.15 g + 4A / 0.1 g Ethyl acetate 75.3 73.8 74.7
4A / 0.25 g Ethyl acetate 78.1 74.9 77.6
2A / 0.25 g Ethyl acetate 78.5 75.2 73.7
7E / 0.15 g + 4A 0.1 g Ethyl formate 60.8 65.1 65.5
<8-3> HPLC chromatogram analysis of anastrazole
In order to indirectly estimate whether decomposition or modification products of anastrazole are produced during the preparation of microparticles using ethyl acetate/PLGA (75:25)/NaOH as in Example <8-1>, various samples were prepared (as in Example <8-1>) and their chromatograms were analyzed.
As seen in Fig. 26, when anastrazolewas encapsulated in the microparticles and then recovered, the same anastrazole identical to the standard product was recovered. Therefore, it was confirmed that no decomposition or modification products of anastrazole are produced.
<Example 9>
Preparation of microparticles encapsulating olanzapine
<9-1> Preparation of microparticles encapsulating olanzapine using ethyl acetate
0.15 g of 7E and 0.1 g of 4A or 2A was dissolved in 4 mL of ethyl acetate. Then, 60 mg of olanzapine was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. After adding 5 mL of 10 M NaOH to the resultant o/w emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was further added and, after stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
As seen in Fig. 27, microspheres according to the method of the present invention were prepared well.
<9-2> Measurement of olanzapine encapsulation ratio
Some of the microparticles including olanzapine were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with ethanol, the solution was filtered using a 0.45 ㎛ syringe filter to remove the PLGA precipitate. Some of the filtrate (20 ㎕) was subjected to HPLC (Shimadzu LC-20AD, Luna 5 m C18(2) column) for measurement of olanzapine concentration. Drug encapsulation ratio (%) was calculated using the equations given in Example <7-2>.
As seen in Table 7, the microparticles prepared according to the method of the present invention showed high olanzapine encapsulation ratio and good batch reproducibility, with similar encapsulation ratios between batches. Encapsulation ratio of 7E/4A formulation was 83.5 ± 4.4%, and that for 7E/2A was 79.8 ± 2.7%.
Table 7
PLGA / quantity Organic solvent Encapsulation ratio (%)
Batch 1 Batch 2 Batch 3 Batch 4
7E / 0.15 g + 4A / 0.1 g Ethyl acetate 84.3 82.8 78.1 88.8
7E / 0.15 g + 2A / 0.1 g Ethyl acetate 81.0 81.1 75.8 81.3
<Example 10>
Preparation of microparticles encapsulating risperidone
<10-1> Preparation of microparticles encapsulating risperidone using ethyl formate
0.25 g of 4A was dissolved in 4 mL of ethyl formate. Then, 60 mg of risperidone was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. After adding 5 mL of 8 M NaOH to the resultant o/w emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was further added and, after stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
As seen in Fig. 28, microspheres according to the method of the present invention were prepared well.
<10-2> Measurement of risperidone encapsulation ratio
Some of the microparticles including risperidone were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with ethanol, the solution was filtered to remove the PLGA precipitate. Some of the filtrate (20 ㎕) was subjected to HPLC (Shimadzu LC-20AD) for measurement of risperidone concentration. Drug encapsulation ratio (%) was calculated using the equations given in Example <7-2>.
As seen in Table 8, the microparticles prepared according to the method of the present invention showed high risperidone encapsulation ratio and good batch reproducibility, with similar encapsulation ratios between batches. Average encapsulation ratio of 3 batches was 75.0 ± 1.4%.
Table 8
PLGA / quantity Organic solvent Encapsulation ratio (%)
Batch 1 Batch 2 Batch 3
4A / 0.25 g Ethyl formate 75.2 73.6 76.3
<Example 11>
Preparation of microparticles encapsulating aripiprazole
<11-1> Preparation of microparticles encapsulating aripiprazole using ethyl formate
0.25 g of 4A was dissolved in 4 mL of ethyl formate. Then, 60 mg of aripiprazole was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. After adding 5 mL of 8 M NaOH to the resultant o/w emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was further added and, after stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
As seen in Fig. 29, microspheres according to the method of the present invention were prepared well.
<11-2> Measurement of aripiprazole encapsulation ratio
Some of the microparticles including aripiprazole were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with ethanol, the solution was filtered to remove the PLGA precipitate. Some of the filtrate (20 ㎕) was subjected to HPLC (Shimadzu LC-20AD) for measurement of aripiprazole concentration. Drug encapsulation ratio (%) was calculated using the equations given in Example <7-2>.
As seen in Table 9, the microparticles prepared according to the method of the present invention showed high aripiprazole encapsulation ratio and good batch reproducibility, with similar encapsulation ratios between batches. Average encapsulation ratio of 3 batches was 72.3 ± 2.0%.
Table 9
PLGA / quantity Organic solvent Encapsulation ratio (%)
Batch 1 Batch 2 Batch 3
4A / 0.25 g Ethyl formate 72.2 74.3 70.3
<Example 12>
Preparation of microparticles encapsulating docetaxel, piroxicam, rivastigmine, tolterodine
<12-1> Preparation of microparticles encapsulating docetaxel, piroxicam, rivastigmine or tolterodine
50 mg of docetaxel was dissolved in 4 mL of ethyl acetate, 50 mg of piroxicam was dissolved in 4 mL of ethyl formate, 40 ㎕ of rivastigmine was dissolved in 4 mL of ethyl formate, and 40 mg of tolterodine was dissolved in 4 mL of ethyl formate. Then, 0.25g of 7E was dissolved to prepare a dispersed phase. The solution was added to 40 mL of 0.5% PVA aqueous solution and stirred. After adding 5 mL of 7 M NaOH to the resultant o/w emulsion, followed by reaction for 30 minutes, 40 mL of distilled water was further added and, after stirring, microparticles were recovered by filtration. The microparticles were redispersed in 16 mL of 0.5% PVA aqueous solution. After adding distilled water to make 80 mL, the solution was stirred. After filtration, the microparticles were dried overnight in a vacuum dryer.
<12-2> Measurement of encapsulation ratio of docetaxel, piroxicam, rivastigmine or tolterodine
Some of the microparticles including each of docetaxel, piroxicam, rivastigmine or tolterodine were accurately weighed and dissolved in 4 mL of tetrahydrofuran. After diluting 6 times with ethanol, the solution was filtered to remove the PLGA precipitate. Some of the filtrate (20 ㎕) was subjected to HPLC (Shimadzu LC-20AD) for measurement of docetaxel, piroxicam, rivastigmine or tolterodine concentration, respectively. Drug encapsulation ratio (%) was calculated using the equations given in Example <7-2>.
As seen in Table 10, the microparticles prepared according to the method of the present invention showed high drug encapsulation ratio.
Table 10
Drug Organic solvent Encapsulation ratio (%)
Batch 1 Batch 2 Batch 3
docetaxel Ethyl acetate 83.2 80.2 84.2
piroxicam Ethyl formate 76.2 81.2 79.2
rivastigmine Ethyl acetate 74.2 79.2 78.1
tolterodine Ethyl formate 70.3 77.3 73.2
As described above, the present invention provides a novel method for preparing a polymeric microsphere comprising the step of removing a water-insoluble organic solvent using a base or an acid, a polymeric microsphere prepared by the method, and a composition for drug delivery comprising the polymeric microsphere. According to the present invention, a drug-containing polymer microsphere may be prepared quickly and simply without the solvent evaporation or solvent extraction process, thereby reducing water consumption and minimizing wastewater generation. Therefore, the present invention can be effectively used in pharmaceutical and/or medical industry.

Claims (10)

  1. A method for preparing a polymeric microsphere, including:
    (a) preparing an oil-in-water (O/W), oil-in-oil (O/O) or water-in-oil-in-water (W/O/W) emulsion including a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent and
    (b) adding to the emulsion prepared in (a) a base solution or an acid solution to remove the water-insoluble organic solvent from the emulsion.
  2. The method of claim 1, wherein the polymer compound is one selected from the group consisting of polylactic acid, polylactide, polylactic-co-glycolic acid, polylactide-co-glycolide(PLGA), polyphosphazine, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, a copolymer of lactic acid and caprolactone, polycaprolactone, polyhydroxyvalerate, polyhydroxybutyrate, polyamino acid, a copolymer of lactic acid and amino acid, and a mixture thereof.
  3. The method of claim 1, wherein the drug is one or more selected from the group consisting of progesterone, haloperidol, thiothixene, olanzapine, clozapine, bromperidol, pimozide, risperidone, ziprasidone, diazepma, ethyl loflazepate, alprazolam, nemonapride, fluoxetine, sertraline, venlafaxine, donepezil, tacrine, galantamine, rivastigmine, selegiline, ropinirole, pergolide, trihexyphenidyl, bromocriptine, benztropine, colchicine, nordazepam, etizolam, bromazepam, clotiazepam, mexazolum, buspirone, goserelin acetate, somatotropin, leuprolide acetate, octreotide, cetrorelix, sandostatin acetate, gonadotropin, fluconazole, itraconazole, mizoribine, cyclosporin, tacrolimus, naloxone, naltrexone, cladribine, chlorambucil, tretinoin, carmusitne, anagrelide, doxorubicin, anastrozole, idarubicin, cisplatin, dactinomycin, docetaxel, paclitaxel, raltitrexed, epirubicin, letrozole, mefloquine, primaquine, oxybutynin, tolterodine, allylestrenol, lovostatin, simvastatin, provastatin, atrovastatin, alendronate, salcatonin, raloxifene, oxadrolone, conjugated estrogen, estradiol, estradiol valerate, estradiol benzoate, ethinyl estradiol, etonogestrel, levonorgestrel, tibolone, norethisterone and piroxicam.
  4. The method of claim 1, wherein the water-insoluble organic solvent is water-insoluble compound having one backbone selected from the group consisting of acid halogen, anhydride, phosphoric anhydride, ester, carboxylic esters, phosphoric esters compound, sulfuric acid esters compound, nitric esters compound, boric acid esters, amide and carboxylic amides.
  5. The method of claim 1, wherein the water-insoluble organic solvent is one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl formate, ethyl formate, isopropyl formate, propyl formate, butyl formate, methyl dichloroacetate, methyl chloroacetate, ethyl chloroacetate, ethyl dichloroacetate, methyl fluoroacetate, methyl difluoroacetate, ethyl fluoroacetate, ethyl difluoroacetate, maleic anhydride, acetic anhydride, propionic anhydride, phosphoric anhydride, acetamide, propionamide, butylamide and carboxyl amide
  6. The method of claim 1, wherein the dispersion solvent is aqueous dispersion solvent which is selected from the group consisting of polyvinyl alcohol aqueous solution, aqueous solution of polysorbates or co-solvent thereof, or non-aqueous dispersion solvent which is selected from the group consisting of vegetable oil, toluene, xylene and silicon oil containing emulsifier such as glycerin esters of fatty acids or lecithin.
  7. The method of claim 1, wherein the base is selected from the group consisting of NaOH, LiOH, KOH, NH4OH, Cu(OH)2 and Fe(OH)3.
  8. The method of claim 1, wherein the acid is HCl, HNO3, H2SO4, CH3COOH, H3BO3 and H2CO3.
  9. A polymer microsphere prepared by the method of anyone of selected from the group consisting of claims 1 to 8.
  10. A composition for drug delivery comprising the polymer microsphere of claim 9 as an effective ingredient.
PCT/KR2009/006690 2008-11-14 2009-11-13 Method for preparing microspheres and microspheres produced thereby WO2010056065A2 (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
MX2011004994A MX2011004994A (en) 2008-11-14 2009-11-13 Method for preparing microspheres and microspheres produced thereby.
BRPI0921048-2A BRPI0921048B1 (en) 2008-11-14 2009-11-13 METHOD FOR PREPARING MICROSPHERES, MICROSPHERES PRODUCED BY THIS METHOD, AND DRUG RELEASE COMPOSITION COMPRISING THE SAME
AU2009314787A AU2009314787B2 (en) 2008-11-14 2009-11-13 Method for preparing microspheres and microspheres produced thereby
CN200980144588.5A CN102209531B (en) 2008-11-14 2009-11-13 Method for preparing microspheres and microspheres produced thereby
CA2743600A CA2743600C (en) 2008-11-14 2009-11-13 Method for preparing microspheres and microspheres produced thereby
EP09826297.5A EP2376071A4 (en) 2008-11-14 2009-11-13 Method for preparing microspheres and microspheres produced thereby
JP2011536249A JP5588993B2 (en) 2008-11-14 2009-11-13 Method for producing polymer fine sphere and polymer fine sphere produced by the method
IL212875A IL212875A (en) 2008-11-14 2011-05-12 Method for preparing microspheres and microspheres produced thereby
US13/106,400 US8697127B2 (en) 2008-11-14 2011-05-12 Method for preparing microspheres and microspheres produced thereby
ZA2011/04399A ZA201104399B (en) 2008-11-14 2011-06-13 Method for preparing microspheres and microspheres produced thereby

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR20080113304 2008-11-14
KR10-2008-0113304 2008-11-14

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US13/106,400 Continuation US8697127B2 (en) 2008-11-14 2011-05-12 Method for preparing microspheres and microspheres produced thereby

Publications (3)

Publication Number Publication Date
WO2010056065A2 true WO2010056065A2 (en) 2010-05-20
WO2010056065A9 WO2010056065A9 (en) 2010-09-02
WO2010056065A3 WO2010056065A3 (en) 2010-10-21

Family

ID=42170537

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2009/006690 WO2010056065A2 (en) 2008-11-14 2009-11-13 Method for preparing microspheres and microspheres produced thereby

Country Status (12)

Country Link
US (1) US8697127B2 (en)
EP (1) EP2376071A4 (en)
JP (1) JP5588993B2 (en)
KR (1) KR101181563B1 (en)
CN (1) CN102209531B (en)
AU (1) AU2009314787B2 (en)
BR (1) BRPI0921048B1 (en)
CA (1) CA2743600C (en)
IL (1) IL212875A (en)
MX (1) MX2011004994A (en)
WO (1) WO2010056065A2 (en)
ZA (1) ZA201104399B (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012156561A1 (en) * 2011-05-13 2012-11-22 Conicet - Cons. Nac. De Investigaciones Científicas Y Técnicas Controlled-release injectable microparticle
JP2013531061A (en) * 2010-07-21 2013-08-01 エスケー ケミカルス カンパニー リミテッド Method for producing polymer microspheres and polymer microspheres produced by the method (Method for preparing microspheres and microspheres produced thereby)
CN109432070A (en) * 2018-11-09 2019-03-08 深圳万和制药有限公司 The preparation method and vitaminAD pellet of high uniformity vitaminAD pellet
CN108096212B (en) * 2017-12-25 2020-06-09 河北科技大学 Preparation method of drug microspheres with hydroxyethyl starch 200/0.5 as carrier
RU2731489C1 (en) * 2017-11-30 2020-09-03 Джи2Джибио, Инк. Preparation for injection with delayed release containing donepezil and method for obtaining said preparation
US10800738B2 (en) 2017-12-05 2020-10-13 Sunovion Pharmaceuticals Inc. Crystal forms and production methods thereof
US10835495B2 (en) 2012-11-14 2020-11-17 W. R. Grace & Co.-Conn. Compositions containing a biologically active material and a non-ordered inorganic oxide material and methods of making and using the same
US10874639B2 (en) 2017-12-05 2020-12-29 Sunovion Pharmaceuticals Inc. Nonracemic mixtures and uses thereof
US11160758B2 (en) 2019-06-04 2021-11-02 Sunovion Pharmaceuticals Inc. Modified release formulations and uses thereof
RU2799939C1 (en) * 2019-07-12 2023-07-14 Джи2Джибио, Инк. Long-acting dosage form containing rivastigmine and a method of its manufacture
AU2020312361B2 (en) * 2019-07-12 2024-05-09 G2Gbio, Inc. Long-lasting formulation containing rivastigmine, and method for preparing same

Families Citing this family (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101785515B1 (en) * 2010-11-08 2017-10-16 에스케이케미칼주식회사 Pharmaceutical composition containing microspheres loaded with olanzapine as an active ingredient
KR20120048811A (en) * 2010-11-08 2012-05-16 에스케이케미칼주식회사 Pharmaceutical composition containing microspheres loaded with anastrozole as an active ingredient
US9301920B2 (en) 2012-06-18 2016-04-05 Therapeuticsmd, Inc. Natural combination hormone replacement formulations and therapies
HUE055562T2 (en) 2011-11-23 2021-11-29 Therapeuticsmd Inc Natural combination hormone replacement formulations and therapies
CN103126997B (en) * 2011-12-01 2016-08-03 中国人民解放军军事医学科学院毒物药物研究所 Sustained-release micro-spheres containing risperidone and the like and preparation method thereof
US20150196640A1 (en) 2012-06-18 2015-07-16 Therapeuticsmd, Inc. Progesterone formulations having a desirable pk profile
US20130338122A1 (en) 2012-06-18 2013-12-19 Therapeuticsmd, Inc. Transdermal hormone replacement therapies
US10806740B2 (en) 2012-06-18 2020-10-20 Therapeuticsmd, Inc. Natural combination hormone replacement formulations and therapies
US10806697B2 (en) 2012-12-21 2020-10-20 Therapeuticsmd, Inc. Vaginal inserted estradiol pharmaceutical compositions and methods
US10568891B2 (en) 2012-12-21 2020-02-25 Therapeuticsmd, Inc. Vaginal inserted estradiol pharmaceutical compositions and methods
US10471072B2 (en) 2012-12-21 2019-11-12 Therapeuticsmd, Inc. Vaginal inserted estradiol pharmaceutical compositions and methods
US11246875B2 (en) 2012-12-21 2022-02-15 Therapeuticsmd, Inc. Vaginal inserted estradiol pharmaceutical compositions and methods
US9180091B2 (en) 2012-12-21 2015-11-10 Therapeuticsmd, Inc. Soluble estradiol capsule for vaginal insertion
US11266661B2 (en) 2012-12-21 2022-03-08 Therapeuticsmd, Inc. Vaginal inserted estradiol pharmaceutical compositions and methods
US10537581B2 (en) 2012-12-21 2020-01-21 Therapeuticsmd, Inc. Vaginal inserted estradiol pharmaceutical compositions and methods
KR101453996B1 (en) * 2012-12-27 2014-10-28 이화여자대학교 산학협력단 Method for producing microspheres using methyl propionate
CN103792166B (en) * 2014-01-22 2016-06-01 西安航天化学动力厂 A kind of method measuring spherical ammonium perchlorate particle size
WO2015152299A1 (en) * 2014-03-31 2015-10-08 株式会社日本触媒 Particulate water absorbent and method for producing same
RU2016143081A (en) 2014-05-22 2018-06-26 Терапьютиксмд, Инк. NATURAL COMBINED HORMONE SUBSTITUTION COMPOSITIONS AND THERAPIES
WO2016018993A1 (en) 2014-07-29 2016-02-04 Therapeuticsmd, Inc. Transdermal cream
US10328087B2 (en) 2015-07-23 2019-06-25 Therapeuticsmd, Inc. Formulations for solubilizing hormones
KR20180126582A (en) 2016-04-01 2018-11-27 쎄러퓨틱스엠디, 인코퍼레이티드 Steroid hormone pharmaceutical composition
US10286077B2 (en) 2016-04-01 2019-05-14 Therapeuticsmd, Inc. Steroid hormone compositions in medium chain oils
KR20180058430A (en) 2016-11-24 2018-06-01 가톨릭대학교 산학협력단 Pullulan acetate microsphere containing bioactive substance and preparing method thereof
CN106902387A (en) * 2017-03-18 2017-06-30 浙江臻我生物技术有限公司 A kind of composition for skin filling and preparation method thereof
CN107157957A (en) * 2017-05-25 2017-09-15 长春金赛药业股份有限公司 Progesterone sustained-release micro-spheres and nanoparticle, its preparation method and progesterone are slow-release injected
CN107157956B (en) * 2017-05-25 2021-02-05 长春金赛药业有限责任公司 Skeleton type progesterone sustained release microspheres, preparation method thereof and progesterone sustained release injection
CN108498456B (en) * 2018-05-16 2021-01-01 丽珠医药集团股份有限公司 Aripiprazole sustained-release microspheres and preparation method thereof
CN110840828B (en) * 2018-08-20 2021-12-21 浙江长典药物技术开发有限公司 Preparation method of zinc gluconate oral liquid
JP7296520B2 (en) * 2019-03-19 2023-06-22 株式会社リーゼンバイオテク Biodegradable polymer microparticles containing steroid drug and method for producing the same
EP4053098A4 (en) * 2019-10-31 2023-12-13 Daikin Industries, Ltd. Method for manufacturing fluoroacetic acid ester
US11633405B2 (en) 2020-02-07 2023-04-25 Therapeuticsmd, Inc. Steroid hormone pharmaceutical formulations
CN111728957B (en) * 2020-07-06 2022-04-19 济南大学 Tolterodine long-acting sustained-release microsphere and preparation method thereof
CN111643483B (en) * 2020-07-06 2022-03-29 济南大学 Method for preparing galanthamine sustained-release microspheres
KR102237737B1 (en) * 2020-07-09 2021-04-08 에이치엘비제약 주식회사 Methods for preparation of donepezil loaded sustained-release PLGA microsphere
US20230414601A1 (en) * 2020-11-30 2023-12-28 Lg Chem, Ltd. Injectable composition containing caspase inhibitor, and preparation method therefor
CN114028339B (en) * 2021-09-15 2023-05-02 济南大学 rivastigmine-PLGA long-acting slow-release microsphere for injection and process
CN114081867B (en) * 2021-11-08 2023-12-19 中国药科大学 Method for improving drug loading rate of microspheres
CN114377200B (en) * 2022-01-12 2023-03-24 北京阅色科技发展中心(有限合伙) Biodegradable hydrophilic polymer microsphere for facial injection filling and preparation method thereof
DE102022113551A1 (en) 2022-05-30 2023-11-30 Carl Zeiss Ag Optical fiber with a layer to reduce reflection and retardance

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4389840A (en) 1979-07-10 1983-06-28 Rieter Machine Works Limited Method of automatically doffing the full bobbin packages from, and donning the empty bobbin tubes onto, the spindles of a preparatory spinning machine
US4530840A (en) 1982-07-29 1985-07-23 The Stolle Research And Development Corporation Injectable, long-acting microparticle formulation for the delivery of anti-inflammatory agents
WO1998028357A1 (en) 1996-12-20 1998-07-02 Connaught Laboratories Limited Biodegradable targetable microparticle delivery system
US6368632B1 (en) 1993-11-19 2002-04-09 Janssen Pharmaceutica Microencapsulated 3-piperidinyl-substituted 1,2-benzisoxazoles and 1,2-benzisothiazoles
US6572894B2 (en) 1995-11-24 2003-06-03 Actipac Biosystems Gmbh Process for the production of morphologically uniform microcapsules and microcapsules that are produced according to this process
US6884435B1 (en) 1997-01-30 2005-04-26 Chiron Corporation Microparticles with adsorbent surfaces, methods of making same, and uses thereof

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5792477A (en) * 1996-05-07 1998-08-11 Alkermes Controlled Therapeutics, Inc. Ii Preparation of extended shelf-life biodegradable, biocompatible microparticles containing a biologically active agent
US20040126431A1 (en) * 2000-10-03 2004-07-01 Frederic Lagarce Method for preparing microspheres containing a water-soluble substance
CN1194688C (en) * 2001-07-03 2005-03-30 山东绿叶制药股份有限公司 Slow releasing microspheres of transcutaneous huperzine A and its derivative or salt for injection and its preparing process
CN1398584A (en) * 2002-07-15 2003-02-26 裴福兴 Slow-releasing bFGF-PLGA microball and its prepn and use
JP2008518881A (en) * 2003-07-18 2008-06-05 オークウッド ラボラトリーズ，エル．エル．シー． Prevention of molecular weight reduction, impurity formation and gelation of polymer in polymer composition
JP5302888B2 (en) * 2006-08-31 2013-10-02 エスケー ケミカルズ カンパニー リミテッド Method for producing drug-containing polymer microspheres and drug-containing polymer microspheres produced by the method
CN1947721B (en) * 2006-09-18 2011-01-26 厦门大学 Method for preparing epirubicin slow-release prepn
TWI362947B (en) * 2007-03-08 2012-05-01 Univ Kaohsiung Medical Controlled release pharmaceutical composition and manufacture method thereof
CN100548278C (en) * 2007-05-17 2009-10-14 中国人民解放军军事医学科学院生物工程研究所 A kind of preparation method that improves rate of packaging microspheres of naltrexone

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4389840A (en) 1979-07-10 1983-06-28 Rieter Machine Works Limited Method of automatically doffing the full bobbin packages from, and donning the empty bobbin tubes onto, the spindles of a preparatory spinning machine
US4530840A (en) 1982-07-29 1985-07-23 The Stolle Research And Development Corporation Injectable, long-acting microparticle formulation for the delivery of anti-inflammatory agents
US6368632B1 (en) 1993-11-19 2002-04-09 Janssen Pharmaceutica Microencapsulated 3-piperidinyl-substituted 1,2-benzisoxazoles and 1,2-benzisothiazoles
US6544559B2 (en) 1993-11-19 2003-04-08 Alkermes Controlled Therapeutics Inc. Ii Microencapsulated 3-piperidinyl-substituted 1,2-benzisoxazoles and 1,2-benzisothiazoles
US6572894B2 (en) 1995-11-24 2003-06-03 Actipac Biosystems Gmbh Process for the production of morphologically uniform microcapsules and microcapsules that are produced according to this process
WO1998028357A1 (en) 1996-12-20 1998-07-02 Connaught Laboratories Limited Biodegradable targetable microparticle delivery system
US6884435B1 (en) 1997-01-30 2005-04-26 Chiron Corporation Microparticles with adsorbent surfaces, methods of making same, and uses thereof

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
DEUTSCHER, M.: "Enzymology", vol. 182, 1990, ACADEMIC PRESS, article "Guide to Protein Purification Methods"
MANIATIS ET AL.: "Cold Spring Harbor Laboratory", 1982, COLD SPRING HARBOR, article "Molecular Cloning: A Laboratory Manual"
SAMBROOK ET AL.: "Molecular Cloning: A Laboratory Manual", 1989, COLD SPRING HARBOR LABORATORY PRESS
See also references of EP2376071A4

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013531061A (en) * 2010-07-21 2013-08-01 エスケー ケミカルス カンパニー リミテッド Method for producing polymer microspheres and polymer microspheres produced by the method (Method for preparing microspheres and microspheres produced thereby)
US20130224257A1 (en) * 2010-07-21 2013-08-29 Ewha University - Industry Collaboration Foundation Method for preparing microspheres and microspheres produced thereby
WO2012156561A1 (en) * 2011-05-13 2012-11-22 Conicet - Cons. Nac. De Investigaciones Científicas Y Técnicas Controlled-release injectable microparticle
US10835495B2 (en) 2012-11-14 2020-11-17 W. R. Grace & Co.-Conn. Compositions containing a biologically active material and a non-ordered inorganic oxide material and methods of making and using the same
RU2731489C1 (en) * 2017-11-30 2020-09-03 Джи2Джибио, Инк. Preparation for injection with delayed release containing donepezil and method for obtaining said preparation
US11370753B2 (en) 2017-12-05 2022-06-28 Sunovion Pharmaceuticals Inc. Crystal forms and production methods thereof
US11767293B2 (en) 2017-12-05 2023-09-26 Sunovion Pharmaceuticals Inc. Crystal forms and production methods thereof
US10800738B2 (en) 2017-12-05 2020-10-13 Sunovion Pharmaceuticals Inc. Crystal forms and production methods thereof
US10874639B2 (en) 2017-12-05 2020-12-29 Sunovion Pharmaceuticals Inc. Nonracemic mixtures and uses thereof
US11517558B2 (en) 2017-12-05 2022-12-06 Sunovion Pharmaceuticals Inc. Nonracemic mixtures and uses thereof
CN108096212B (en) * 2017-12-25 2020-06-09 河北科技大学 Preparation method of drug microspheres with hydroxyethyl starch 200/0.5 as carrier
CN109432070A (en) * 2018-11-09 2019-03-08 深圳万和制药有限公司 The preparation method and vitaminAD pellet of high uniformity vitaminAD pellet
US11160758B2 (en) 2019-06-04 2021-11-02 Sunovion Pharmaceuticals Inc. Modified release formulations and uses thereof
US11654113B2 (en) 2019-06-04 2023-05-23 Sunovion Pharmaceuticals Inc. Modified release formulations and uses thereof
RU2799939C1 (en) * 2019-07-12 2023-07-14 Джи2Джибио, Инк. Long-acting dosage form containing rivastigmine and a method of its manufacture
AU2020312361B2 (en) * 2019-07-12 2024-05-09 G2Gbio, Inc. Long-lasting formulation containing rivastigmine, and method for preparing same

Also Published As

Publication number Publication date
JP2012508731A (en) 2012-04-12
US8697127B2 (en) 2014-04-15
WO2010056065A3 (en) 2010-10-21
US20110217341A1 (en) 2011-09-08
WO2010056065A9 (en) 2010-09-02
AU2009314787A1 (en) 2011-07-07
CA2743600A1 (en) 2010-05-20
ZA201104399B (en) 2012-02-29
BRPI0921048A2 (en) 2015-12-29
CN102209531A (en) 2011-10-05
IL212875A0 (en) 2011-07-31
IL212875A (en) 2017-06-29
CA2743600C (en) 2016-11-08
JP5588993B2 (en) 2014-09-10
EP2376071A4 (en) 2014-04-16
KR101181563B1 (en) 2012-09-10
KR20100054750A (en) 2010-05-25
CN102209531B (en) 2014-08-27
MX2011004994A (en) 2011-09-28
BRPI0921048B1 (en) 2022-02-15
AU2009314787B2 (en) 2014-03-06
EP2376071A2 (en) 2011-10-19

Similar Documents

Publication Publication Date Title
WO2010056065A2 (en) Method for preparing microspheres and microspheres produced thereby
WO2016114521A1 (en) Tablet form dutasteride composition having improved stability
WO2016068457A1 (en) Pharmaceutical composition for oral administration comprising taxane
WO2020197185A1 (en) Compositions of dispersed phase for preparation of apixaban-loaded microspheres and biocompatible polymer-based apixaban-loaded microspheres prepared therefrom
WO2013085224A1 (en) Bitter taste masked oral thin film formulation of sildenafil citrate
WO2020197190A1 (en) Method for preparing biocompatible polymer-based apixaban-loaded microspheres
WO2022050783A1 (en) Sustained-release microparticles for sustained release of drug
WO2023080753A1 (en) Pharmaceutical kit for parenteral co-administration
WO2023101348A1 (en) Microparticles containing leuprolide, and preparation method thereof
WO2020130585A1 (en) Sustained-release injection comprising deslorelin, and preparation method therefor
WO2016114602A1 (en) Novel pharmaceutical composition
WO2023038450A1 (en) Pharmaceutical composition comprising large physiologically active substance and excipient
WO2022215899A1 (en) Sustained-release lipid pre-concentrate
WO2023038202A1 (en) Sustained-release microsphere using biodegradable polymer, and method for preparing same
WO2021261926A1 (en) Long-acting injection for dementia treatment
WO2023158228A1 (en) Sustained-release injectable composition containing deslorelin
WO2021206428A1 (en) Rosmarinic acid derivative, rosmarinic acid-derived particles, and composition comprising same for treating inflammatory disease
WO2021242021A1 (en) Controlled release microspheres containing glucagon-like peptide 1 agonist, and method for producing same
WO2022114876A1 (en) Injectable composition containing caspase inhibitor, and preparation method therefor
EP4017517A1 (en) Pharmaceutical formulations comprising sodium palmitoyl-l-prolyl-l-prolyl-glycyl-l-tyrosinate and methods for preparing the same
WO2023200036A1 (en) Method for preparing microparticles containing moxidectin and sustained-release injectable composition comprising microparticles prepared by same preparation method
WO2024101859A1 (en) Sustained-release injectable preparation comprising dexamethasone acetate and preparation method therefor
WO2024219854A1 (en) Method for preparing liraglutide-containing plga microspheres, sustained-release microspheres prepared according to same, and composition for injectable formulation comprising same
WO2012015211A2 (en) Opthalmic formulation containing cyclosporine a
WO2023200035A1 (en) Microparticles containing moxidectin and sustained-release injection composition containing same

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200980144588.5

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09826297

Country of ref document: EP

Kind code of ref document: A2

WWE Wipo information: entry into national phase

Ref document number: MX/A/2011/004994

Country of ref document: MX

WWE Wipo information: entry into national phase

Ref document number: 2743600

Country of ref document: CA

Ref document number: 212875

Country of ref document: IL

WWE Wipo information: entry into national phase

Ref document number: 2011536249

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2009314787

Country of ref document: AU

WWE Wipo information: entry into national phase

Ref document number: 1214/MUMNP/2011

Country of ref document: IN

WWE Wipo information: entry into national phase

Ref document number: 2009826297

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2009314787

Country of ref document: AU

Date of ref document: 20091113

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: PI0921048

Country of ref document: BR

Kind code of ref document: A2

Effective date: 20110513