PL195574B1 - Dry powder active agent pulmonary delivery - Google Patents

Abstract

The present invention is directed to particulate compositions and methods for delivering an active agent to the lung of a human patient. The active agent formulation is in dry powder form and exhibits (i) low moisture sorption, and (ii) a resistance to hygrosscopic growth, particularly under simulated lung conditions.

Description

Description of the invention

The invention relates to particles for administering an active ingredient to the alveoli, a method for producing these particles and the use of a hygroscopic growth inhibitor.

Pulmonary administration of the active ingredients has been found to be an effective route of administration for the local and systemic administration of drugs. Pulmonary active ingredient preparations are intended for administration to a patient and are in the form of an inhaled drug dispersion so that the active ingredient contained in the dispersion can reach the lungs. Certain medications administered into the lungs have been found to be easily absorbed via the alveolar area directly into the bloodstream. However, the percentage of inhaled medication that actually reaches deep into the lungs is quite small. When delivered to the lungs, drug losses averaged about 30% in the device and about 35% in the oropharynx (upper respiratory tract). Of the remaining 35%, about 20% of the drug is lost in the conductive airways and about 15% is absorbed in the alveolar area. As pointed out by Gonda et al. in Critical Reviews in Therapeutic Drug Carrier Systems, Vol. 6, ed. 4 (1990) pp. 273-313, drug absorption in the distal airways and alveoli should be faster than in the upper airways because the diffusion barriers are thinner and the surface area is larger in these regions. However, since only a small fraction of the inhaled drug actually reaches the vesicle surface, a new approach is needed to increase the amount of drug that will eventually reach the circulatory system.

In one attempt to solve this problem, U.S. Patent No. 5,506,203 describes the use of permeation enhancers to increase absorption by the epithelial cell layer in the lower respiratory tract and, consequently, increase the amount of the drug reaching the circulatory system. The inhaled compounds are administered as particles less than 10 mm in diameter. Permeation enhancers used are surfactants, fatty acid salts, bile acid salts and their derivatives, and others. Similarly, U.S. Patent No. 5,451,569 describes the use of a pulmonary surfactant to improve the absorption of proteins and peptides in the lung.

International publication WO 96/32149 describes the pulmonary administration of aerosolized drugs which are in the form of dispersible dry powders to eliminate the need for permeation enhancers. Such drugs are readily absorbed in the lungs without the need for permeation enhancers. Similar attempts to increase the bioavailability of inhaled drugs are described in the international publication WO 97/44013. According to this publication, aerodynamically light particles (with a density of less than 0.4 g / cm ³ and a large mean diameter greater than 5 mm) are used to improve the delivery of a therapeutic or diagnostic agent to the alveolar region of the lungs. To further improve the bioavailability of the drug, the international publication WO 98/31346 discloses the incorporation of a surfactant into aerodynamically light particles to facilitate the absorption of the agent and increase its bioavailability for pulmonary delivery.

U.S. Patent No. 3,155,573 discloses a deep lung powder after inhalation containing a drug and a dextran carrier. This powder contains at least 80% of particles with a size of 2-6 mm.

WO 96/19197 describes a pharmaceutical aerosol formulation containing an HFA propellant, a pharmaceutically active polypeptide, and a surfactant which is a C8-C16 fatty acid or a salt thereof, a bile salt, a phospholipid or an alkyl saccharide.

EP 611567 relates to an ultrafine particle inhalation powder containing a drug and hydroxypropyl cellulose or hydroxypropyl methylcellulose. This powder contains at least 80% of particles 0.5-10 mm in size.

Apart from the problem of poor absorption of active substances administered to the lungs by epithelial cells in the lower respiratory tract, another factor causing only a small amount of inhaled drug to penetrate deep into the lungs is hygroscopic growth. Due to their solubility in water, aerosol-forming particles are subject to increased deposition in the upper respiratory tract due to hygroscopic growth (Hickey, et al. Journal of Pharmaceutical Sciences, Vol. 79, No. 11, pp. 1009-1014). To investigate the growth rate of the powders in humid environments, fatty acid coated disodium fluorescein powders were prepared by the coacervation adsorption technique. The coated powders showed a MMAD of about 4-7 mm and a reduced growth rate as compared to the uncoated powders.

PL 195 574 B1

Despite these many attempts to solve the problem, the percentage of drug overall reaching the alveolar surface after inhalation is still quite low. Thus, new and increased efforts are needed to enable an increase in the amount of inhaled drug deposited deep into the lungs which would also increase the bioavailability of inhaled active ingredients.

Not only are particle size and density parameters important for increasing the bioavailability of drugs administered to the alveolar region of the lungs, but also their ability to absorb water as they travel through the lung to the alveoli. It has been found that coating the particle by itself is not sufficient to minimize water absorption in the lung, rather it is the whole particle that must have hygroscopic growth inhibitory properties in order to maintain an adequate particle size distribution in the aerosol as it travels through the lung to help it reach the alveolar surface without early deposition in the upper lung.

The invention relates to particles for administering an active ingredient to the alveoli of a human patient, characterized in that they contain the active ingredient and at least about 40% by weight of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-sulfobutyl ether. cyclodextrins, hydroxyethyl starch, dextranomer, and maltodextrins, which hygroscopic growth inhibitor is incorporated into the particles, wherein the particles exhibit a drop in dose emitted under simulated lung conditions of no greater than about 25%.

Preferably, the particles contain a hygroscopic growth inhibitor selected from the group consisting of hydroxyethyl starch, dextranomer and maltodextrins.

Preferably, the particles contain a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin and b-cyclodextrin sulfobutyl ether.

Preferably, the particles contain hydroxyethyl starch as the hygroscopic growth inhibitor.

Preferably, the particles contain a hygroscopic growth inhibitor in an amount sufficient for the particles to exhibit a moisture uptake rate of no greater than about 0.50% as a function of relative humidity.

Preferably, the particles contain a hygroscopic growth inhibitor in an amount sufficient for the particles to have a total water uptake of no greater than about 30% by weight at a relative humidity of 80%.

Preferably the particles have an emitted dose under ambient conditions of at least 60%.

Preferably, the particles contain about 40-99% by weight of the hygroscopic growth inhibitor.

In particular, the particles contain about 40-60% by weight of the hygroscopic growth inhibitor.

Preferably, the particles are deposited deep into the lungs by more than 20% of the nominal dose when administered to the lungs.

Preferably the particles contain a hygroscopic growth inhibitor which is effective in increasing the bioavailability of the active ingredient when administered to the lungs by at least 5% compared to the bioavailability of the active ingredient contained in the same particles containing the hygroscopic growth inhibitor and delivered to the lungs.

Preferably, the particles contain a protein or a polypeptide as active ingredient.

In particular, the particles contain insulin or calcitonin as the active ingredient.

Preferably, the particles have been spray dried.

Preferably, the particles of the invention as described above and below are in the form of an aerosol for use in administering the active ingredient to the lungs of a human patient.

Preferably, the particles of the invention as described above and below are used in administering the active ingredient to the lungs of a human patient using a dry powder inhaler.

The invention also relates to particles for administering an active ingredient to the alveoli of a human patient, characterized in that they contain the active ingredient and at least about 40% by weight of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-sulfobutyl ether. cyclodextrins, hydroxyethyl starch, dextranomer, and maltodextrins are incorporated into the particles, wherein the particles have a sorption index less than about 6.5.

Preferably, the particles contain a hygroscopic growth inhibitor selected from the group consisting of hydroxyethyl starch, dextranomer and maltodextrins.

Preferably, the particles contain a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin and b-cyclodextrin sulfobutyl ether.

Preferably, the particles contain hydroxyethyl starch as the hygroscopic growth inhibitor.

PL 195 574 B1

Preferably, the particles have an emitted ambient dose of at least 60%.

Preferably, the particles contain about 40-99% by weight of the hygroscopic growth inhibitor.

In particular, the particles contain about 40-60% by weight of the hygroscopic growth inhibitor.

Preferably, the particles are deposited deep into the lungs by more than 20% of the nominal dose when administered to the lungs.

Preferably, the particles contain a hygroscopic growth inhibitor which is effective in increasing the bioavailability of the active ingredient when administered to the lungs by at least 5% compared to the bioavailability of the active ingredient contained in the same particles not containing the hygroscopic growth inhibitor and delivered to the lungs.

Preferably, the particles contain a protein or a polypeptide as active ingredient.

In particular, the particles contain insulin or calcitonin as the active ingredient.

Preferably, the particles have been spray dried.

The invention also relates to particles for administering an active ingredient to the alveoli of a human patient, characterized in that they contain the active ingredient and at least about 40% by weight of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, sulfobutyl ether b. cyclodextrins, hydroxyethyl starch, dextranomer and maltodextrins, incorporated into the particles, which particles maintain an aerosol particle size distribution below 3 mm MMAD when administered to the alveoli.

The invention further relates to a process for preparing particles for administering an active ingredient to the alveoli of a human patient comprising preparing a mixture of (i) at least about 40% by weight (solid) of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl - b-cyclodextrin, b-cyclodextrin sulfobutyl ether, hydroxyethyl starch, dextranomer and maltodextrins, (ii) an active ingredient, and (iii) a solvent;

spray-drying this mixture to obtain homogeneous particles of the hygroscopic growth inhibitor and the active ingredient, wherein the particles exhibit a drop in dose emitted under simulated lung conditions of no more than about 25%.

Preferably a hygroscopic growth inhibitor selected from the group consisting of hydroxyethyl starch, dextranomer and maltodextrins is used.

Preferably a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin and b-cyclodextrin sulfobutyl ether is used.

Preferably, hydroxyethyl starch is used as the hygroscopic growth inhibitor.

Preferably, water is used as the solvent.

Preferably, the homogeneous particles contain about 40-99% by weight of the hygroscopic growth inhibitor, and more preferably about 40-60% by weight of the hygroscopic growth inhibitor.

Preferably, a protein or a polypeptide is used as the active ingredient, in particular insulin or calcitonin.

The invention also relates to the use of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether, hydroxyethyl starch, dextranomer and maltodextrins for the preparation of particles which contain the active ingredient as defined above for administering the active ingredient to the lungs of a patient. human by inhalation of aerosolized active particles.

Preferably the active ingredient is administered using a dry powder inhaler.

The invention also relates to the use of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether, hydroxyethyl starch, dextranomer and maltodextrins for the preparation of particles for lung administration of the active ingredient and deposition into the depth of the lungs by injection of at least about 40% by weight of this hygroscopic growth inhibitor for inhalable dry powder particles containing the active ingredient such that after aerosolization and inhalation, at least 20% of the nominal dose is deposited deep into the lungs.

The particles according to the invention, intended for the administration of the active ingredient into the alveoli of a patient, are prepared by preparing a mixture of the hygroscopic growth inhibitor, the active ingredient and the solvent. The mixture is then spray dried to obtain homogeneous particles containing the hygroscopic growth inhibitor and the active ingredient. The resulting particle size distribution remains less than 3 mm MMAD when administered by inhalation

PL 195 574 B1 deep into the lungs. For the resulting particles, the drop in the emitted dose is no more than 25% under simulated lung conditions. The moisture sorption index for the spray-dried particles is less than about 6.5.

The particles of the invention form a powder for pulmonary administration. These particles contain the active ingredient and the hygroscopic growth inhibitor, and the particle size distribution is less than 3 mm of MMAD when administered to the alveoli. It is surprising that such particles provide increased bioavailability of the active ingredient compared to active ingredient particles without the presence of a hygroscopic growth inhibitor or having a hygroscopic growth inhibitor only adsorbed on their surface. It is believed that by dispersing the hygroscopic growth inhibitor into the particle, rather than merely coating it on the surface, as the particle surface erodes or dissolves as it passes through the airways, new inner layers of the hygroscopic growth inhibitor are exposed, providing the particles with a new layer capable of inhibiting growth. hygroscopic.

As used herein, the following terms have the meanings indicated.

The "active ingredient" as described herein means an agent, drug, compound, substance composition or mixture providing some pharmacological action, often beneficial, which can be demonstrated in vivo or in vitro. These can be foods, food supplements, nutrients, drugs, vaccines, vitamins, and other beneficial agents. As used herein, the terms further refer to any physiologically or pharmacologically active substance exerting a local or systemic effect in a patient.

The term "dry powder" refers to a powder composition that contains well-dispersed solid particles, which are free flowing and capable of (i) being dispersed readily in an inhalation device and (ii) inhalable by a patient such that some of the particles reach the surface. the lungs, which allows the alveoli to penetrate the lungs. Such a powder is considered to be "inhalable or suitable for pulmonary administration." The dry powder typically has less than about 10% moisture, preferably less than 5% moisture, and more preferably less than about 3% moisture.

"Hygroscopic growth inhibitor" (HGI) means any substance which, when incorporated into the particles of the invention at an appropriate concentration, reduces the rate and / or degree of water uptake. Substances suitable for use as hygroscopic growth inhibitors when incorporated into the particles of the invention at a suitable concentration effectively inhibit particle growth due to hygroscopicity under conditions commonly found in the lung by at least 5%, preferably by at least 10%, and more preferably by at least 15%. %, compared to particles containing the same relative amounts of particle components but no HGI.

Hygroscopic growth of particles is generally described in terms of the hygroscopic growth ratio, that is, the ratio of the MMAD of the particles under conditions commonly found in the lung, to the MMAD of the dry particles prior to inhalation. As an example, a particle having a hygroscopic growth ratio of 1 does not change size upon inhalation and exposure to the environmental conditions of the lungs. The hygroscopic growth of the particles is determined experimentally by treating the powders in an environmental chamber simulating lung conditions, i.e. 32-37 ° C and 95-99.5% relative humidity. More specifically, a certain dose of the particles is aerosolized in a growth chamber as described above. The aerosol is then directed to a cascade impact mill to determine the mass median aerodynamic diameter of the particles.

Alternatively, the MMAD of a particular powder composition can be calculated under simulated lung conditions to determine the equilibrium growth ratio. The MMAD of aerosolized powder particles in the lung is determined by calculating the solids concentration (powder to water ratio) at which the aqueous solution of the powder becomes isotonic, i.e. the concentration at which the liquid droplet equilibrates in the lung, which in turn allows the calculation of MMAD of this isotonic drop.

The MMAD of the isotonic drop is then divided by the experimentally determined MMAD of the powder under ambient conditions to give the hygroscopic growth ratio.

Particles containing HGI and having a MMAD less than 3 mm under the simulated lung conditions described above are within the scope of the invention.

“The simulated lung conditions are 32-37 ° C and 95-99.5% relative humidity.

"The sorption index, or" SI, is the sum of the weight gain of a dry powder consisting of particles according to the invention in percent by weight determined at a relative humidity of 10%, 20%, 30% and 40% (25 ° C) , divided by 4. The sorption index is determined using a gravimetric sorption analyzer such as the DVS-1000, manufactured by Moisture Measurements Sys6

PL 195 574 B1 (London, UK) or a moisture balance device, manufactured by VTI Corporation (Hialeah, FL).

"Active ingredient particles means the active ingredient as above defined in the form of particles suitable for pulmonary administration. The particles form a dry powder. It should be understood that more than one active ingredient may be incorporated into an aerosolized formulation of active ingredient and that the term "agent in no way excludes the use of two or more of such agents.

Particles containing "incorporated hygroscopic growth inhibitor" are particles with HGI distributed throughout the particle and not just present as a coating on the surface.

By "pulmonary bioavailability in the lung" is meant the amount of active ingredient which, when deposited in the lungs, is absorbed and becomes available in the circulatory system of a mammal, compared to the amount that is absorbed into the blood from the subcutaneous injection site (% absorption /% deposition) . Representative model systems for determining lung bioavailability include rat, dog, and non-human primates. Relative lung bioavailability can be determined by direct administration into the trachea or by inhalation.

The emitted dose or ED gives an indication of the distribution of the dry powder in a suitable inhalation device after actuation, ie after dispersion. ED is defined as the ratio of the dose emitted to the nominal dose (that is, the mass of the powder per unit dose when placed in a suitable inhalation device prior to its actuation). ED is an experimentally determined parameter and is usually determined using an in vitro measurement system that mimics the administration of the drug to a patient. To determine the ED value, a nominal dry powder dose is placed in a suitable dry powder inhaler which disperses the powder upon actuation. The resulting aerosol cloud is then vacuum pulled from the device and captured on a weighed filter connected to the mouthpiece of the device. The amount of powder reaching the filter is the emitted dose. For example, for a 5 mg dry powder dosage form placed in an inhaler after the powder has dispersed 4 mg of powder is recovered on the weighed filter as described above, the emitted dose for this dry powder composition is: 4 mg (emitted dose) / 5 mg (nominal dose) x 100 = 80%.

For heterogeneous powders, ED values are indicative of drug degradation in the inhalation device after actuation rather than dry powder, and are based on drug weight rather than total powder weight.

“The decrease in the dose emitted under simulated lung conditions represents the ED value at ambient conditions (%) minus the ED value at 32-37 ° C and 95-99.5% relative humidity.

"The dispersible powder is a powder having an ED value of at least about 30%, more preferably 40-50%, and even more preferably at least about 50-60%.

"Mass median diameter or" MMD is a measure of mean particle size, since the powders composed of the particles according to the invention are generally polydisperse (i.e. composed of differently sized fractions of particles). The MMD values reported herein are determined by centrifuge sedimentation, although any of the commonly used mean particle size measurement methods (such as electron microscopy, light scattering, laser diffraction) may be used.

"Mass median aerodynamic diameter or" MMAD is a measure of the aerodynamic size of the dispersed particles. The aerodynamic diameter is used to describe an aerosolized powder in terms of its settling behavior and is the diameter of a unit density sphere having the same settling rate in air as the particle. The aerodynamic diameter captures the particle shape, density, and physical size of the particle. The term MMAD as used herein refers to the midpoint or median of the aerodynamic particle size distribution of the aerosolized powder as defined by cascading impacts, unless otherwise stated.

"Pharmaceutically acceptable excipient or pharmaceutically acceptable carrier refers to an excipient or carrier that can be incorporated into the particles of the invention and then into the lungs together with the particles without significant deleterious toxicological effects on the patient, and particularly on the patient's lungs."

"A pharmacologically effective amount or" physiologically effective amount of a bioactive agent "is the amount of active ingredient present in the particulate dry powder composition described herein and needed to achieve the desired level of the bioactive agent in the bloodstream of the treated patient, to achieve the expected physiological response when such composition is administered. to the lungs. The exact amount will depend on many factors, e.g., the bioactive agent, the specific activity of the composition,

The drug delivery device used, the physical characteristics of the powder, its intended use, and the factors taken into account for each patient, will be readily determined by one skilled in the art based on the information provided in this specification.

The particles of the invention are intended to resist the hygroscopic growth that normally occurs when dry powder formulations are administered into the lungs, thereby ensuring that more inhaled particles reach deep into the lungs. This property of the particles, i.e. resistance to hygroscopic growth, is achieved by the incorporation of a hygroscopic growth inhibitor, i.e. an agent whose presence in the particles effectively reduces the rate and / or degree of water uptake of the particles, especially when exposed to the environmental conditions of the lungs.

Active ingredients for incorporation in the particulate compositions described herein include antibiotics, antiviral agents, antiepileptic agents, analgesics, anti-inflammatory agents, and bronchodilators. Active substances can be inorganic or organic compounds including, but not limited to, drugs that act on peripheral nerves, adrenergic receptors, cholinergic receptors, skeletal muscles, cardiovascular system, smooth muscles, circulatory system, synaptic sites, neuroeffect nodes, endocrine and endocrine systems, immune system, reproductive system, bones, autacoid systems, digestive and excretory systems, histamine system of the central nervous system. Suitable agents may be selected from, e.g., polysaccharides, steroids, hypnotics and sedatives, psychological activators, tranquilizers, anticonvulsants, muscle relaxants, anti-parkinsonian agents, analgesics, anti-inflammatory agents, muscle contractions, antibacterial agents, antimalarials, hormonal agents. including contraceptives, sympathomimetics, polypeptides and proteins capable of producing physiological effects, diuretics, lipid regulating agents, anti-androgenic agents, anti-parasitic agents, anti-cancer agents, hypoglycemics, nutrients and additives, growth additives, fats, anti-inflammatory agents intestines, electrolytes, vaccines, and diagnostics.

Examples of active ingredients suitable for use in the invention include, but are not limited to, calcitonin, erythropoietin (EPO), factor VIII, factor IX, ceredase, cerezyme, cyclosporin, granulocyte colony stimulating factor (GCSF), a-1 protease inhibitor, elkatonin, colony stimulating factor. granulocyte macrophage (GMCSF), growth hormone, human growth hormone (HGH), growth hormone releasing hormone (GHRH), heparin, low molecular weight heparin (LMWH), interferon a, interferon b, interferon g, interleukin-2, releasing hormone luteinizing hormone (LHRH), insulin, somatostatin, somatostatin analogues including octreotide, vasopressin analog, follicle stimulating hormone (FSH), insulin-like growth factor, insulinotropin, interleukin-1 receptor antagonist, interleukin-3, interleukin-6, interleukin-4, interleukin-4 macrophage colony (M-CSF), nerve growth factor, parathyroid hormone (PTH), thymosin a-1, inhibitor IIb / IIIa, antitrypsin a-1, V LA-4, respiratory syncytial virus antibody, cystic fibrosis transmembrane regulator gene (CFTR), deoxyribonuclease (Dnaase), bactericidal permeation protein (BPI), anti-CMV antibody, interleukin-1 receptor, 13-cis retinoic acid, pentamidine isethionate albuterol sulfate, metaproterenol sulfate, beclomethasone dipropionate, triamcinolone acetamide, budesonide acetonide, fluticasone, ipratropium bromide, flunisolide, sodium cromoline, ergotamine tartrate, and analogs, agonists and antagonists of the above substances. Active agents can further include nucleic acids, present as naked nucleic acid molecules, viral vectors, bound viral particles, plasmid DNA or RNA, or other nucleic acid constructs of a type suitable for transfecting or transforming cells, particularly cells of the alveolar region of the lungs. The active ingredients may be in various forms, water-soluble or insoluble, charged or uncharged molecules, components of molecular complexes or pharmacologically acceptable salts. The active substances can be naturally occurring molecules or they can be produced recombinantly, or they can be analogs of naturally occurring or recombinantly produced proteins with one or more amino acids added or deleted. In addition, the active ingredient may include live attenuated or killed viruses suitable for use as vaccines.

The amount of active ingredient in the aerosolized particles will be that amount necessary to deliver a therapeutically effective amount of the active ingredient per unit dose to obtain the desired result. In practice, it will vary widely depending upon the particular agent, its bioactivity, the severity of the condition being treated, the patient population, the dosage regimen and the desired agent.

The therapeutic effect. The particles will typically contain from 1 wt. % to about 99 wt.% % of active ingredient, usually about 2 to 95 wt.%. % of active ingredient, and more usually about 5-85 wt.%. active substance. These particles are particularly suitable for active ingredients which must be delivered at doses of 0.001-100 mg / day, preferably 0.01-50 mg / day.

An essential feature of the particles is that they contain a hygroscopic growth inhibitor. Hygroscopic Growth Inhibitor (HGI) is effective in reducing the rate and / or the extent to which moisture is absorbed by the particles upon inhalation, thereby allowing the particles to retain a MMAD of less than 3mm when delivered to the alveoli.

A substance suitable for use as an HGI is first identified by pre-selection to determine its moisture uptake profile after spray drying; materials with low absorption, such as those of Figure 1, are preferred in the uses of the invention. These HGI substances are then tested for suitability by preparing particles containing an appropriate amount of HGI (typically greater than about 5-10% by weight of the composition). In some cases, the HGI may not only be part of the mass of the powder but also form an additional coating on the surface of the particles. Moisture isotherms are then established for the active ingredient particles containing HGI and for control particles containing the same relative amounts of ingredients in the absence of HGI to determine whether the presence of HGI is effective in reducing the rate or rate of water absorption by the powder. Typically, high and low HGI concentrations are tested to determine useful incorporation ranges for the particulate powders of the invention.

Substances that are useful as hygroscopic growth inhibitors include, but are not limited to: double chain phospholipids, cyclodextrins and their derivatives, hydroxyethyl starch (HES), dextran, dextranomer, maltodextrins, starches, hydroxypropyl methyl cellulose (HPMC), cellulose ethyl ether, and other cellulose derivatives, such as those described in "Cellulosics: Chemical, Biochemical and Material Aspects (Ellis Horwood Series in Polymer Science and Technology) JF, B.Sc. Kennedy, G.O., B.Sc. Phillips, P.A. Williams (publisher) and in Comprehensive Cellulose Chemistry by D. Klemm (publisher), Bertram Philipp, T. Heinze (1998). In some cases, the active ingredient may also act as an inhibitor of hygroscopic growth. The active substances that act as HGI include insulin, salmon calcitonin and PTH.

Double chain phospholipids for use in the present invention include phosphatidylcholines such as 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1 , 2-distearoyl-sn-glycero-3-phosphocholine (DSPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC ) etc. Also suitable for use as hygroscopic growth inhibitors are phosphatidylethanolamines such as 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE), 1,2-di-oleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and similarly derivatized phosphatidylglycerins and phosphatidic acids.

Cyclodextrins are another group of compounds that are useful as hygroscopic growth inhibitors. Cyclodextrins, cyclic oligosaccharides having a truncated cone shape and having a hydrophobic center cavity, consist of more than 6 D-glucose residues. The cyclodextrins to be used according to the invention are respectively a-cyclodextrin (6 glucose residues), b-cyclodextrin (7 glucose residues) and g-cyclodextrin (8 glucose residues) according to the number of glucose residues, as well as derivatives thereof such as 2-hydroxypropyl -b-cyclodextrin (2-HPbC) and b-cyclodextrin sulfonyl butyl ether. 2-HPbC is a particularly preferred excipient as illustrated by its moisture sorption profile in Figure 1. With a target relative humidity of 80%, 2-HPbC showed a weight change of only about 16% due to water uptake over a period of about 8 hours. Cyclodextrin shows a similar profile. The favorable moisture sorption properties of the exemplary b-cyclodextrin (2-SBEbC) sulfobutyl ether formulation are shown in Figure 4. Thus, these substances (i) are quite resistant to water uptake and (ii) have a low water uptake rate making them suitable for suitable substances for incorporation into the powders of the particles according to the invention.

Dextrans which are polysaccharides containing glucose monomers are also useful as hygroscopic growth inhibitors. Dextrans to be used in the present invention have a molecular weight in the range of about 10,000-100,000. Dextran 10, dextran 40, dextran 70 and dextran 75 are preferred. Dextran derivatives such as dextranomer (dextran 2,3-dihydroxypropyl 2-hydroxy-1,3-propanediyl ethers), maltodextran and sodium dextran sulfate can also be used. The resistance of dextrans to moisture uptake is illustrated in a moisture sorption equilibration experiment, which demonstrated that at 70% relative humidity, spray-dried dextran absorbs

Only 19% water, while at 80% relative humidity the extran showed a water sorption of 24% by weight as illustrated in Example 3 and shown in Fig. 1.

Derivatized celluloses such as hydroxypropyl methylcellulose (HPMC), cellulose ethyl hydroxyethyl ether and hydroxypropyl cellulose with a molecular weight of 10,000-400,000 are also useful as hygroscopic growth inhibitors.

Derivatized starches can also be used as hygroscopic growth inhibitors. A particularly preferred hygroscopic growth inhibitor is hydroxyethyl starch (HES) with a molecular weight of about 70,000-400,000 (see e.g. Fig. 2). For a review of HES, see Intensive Care Med (1999) 25: 258-268.

Maltodextrin, hydrolyzed starch and its commercially available derivatives are suitable for use as hygroscopic growth inhibitors. Maltodextrin 40 with an average molecular weight of about 3600 is preferred.

The HGI useful in the particles and the method of the invention provides effective minimization of hygroscopic growth, yet (1) no toxicity at the concentrations used and (2) good powder properties, i.e. no sticky or waxy solids consistency. The toxicity of a given substance can be tested by known methods such as the MTT test, e.g. as described in Int. J. Pharm. 65 (1990) pp. 249-259.

The hygroscopic growth inhibitor is present in the particles in an amount sufficient to minimize hygroscopic particle growth or to prevent hygroscopic particle growth so that the particles retain a particle size below 3 mm after aerosol delivery to the alveoli. The optimal ratio of active ingredient to HGI can be ensured for a given HGI by testing various ratios in an in vitro model such as described herein. For example, the active ingredient is typically combined with an HGI such as hydroxyethyl starch in the following weight ratios: 10/90, 25/75, 50/50, 75/25, and 90/10 to determine which ratios give a significant reduction in degree or rate. uptake of water in powders. Based on these data, the optimal concentration of HGI can be determined. Different HGI, in combination with different active ingredients and optionally additional excipients, will have different optimal concentrations, so that each HGI must be tested separately.

Generally, the particles contain at least about 5-20 wt.% HGI, preferably at least about 20 to 40 wt.% HGI, and more preferably at least about 40-60 wt.% HGI or more. The amount of HGI necessary to reduce the moisture absorption properties of the powder will be lower in situations where the active ingredient is a protein or a polypeptide, since the proteins and polypeptides also inhibit hygroscopic growth. In cases where the active ingredient is not a protein or polypeptide, the particles preferably contain at least about 40% HGI, with the amount of HGI in the particles ranging from about 40% to 99% by weight. The presence of HGI in the particles maximizes the deposition of the aerosolized particles in the lower respiratory tract, particularly on the alveolar surfaces, as opposed to the mouth, throat and upper respiratory tract, thereby increasing the bioavailability of the active ingredient delivered to the lungs.

In addition to the hygroscopic growth inhibitor, the active ingredients in the particles of the invention may optionally be combined with pharmaceutical carriers or excipients which are suitable for administration to the respiratory tract and the lungs. Such carriers may simply serve as fillers when it is desired to reduce the concentration of the active ingredient in the powder that is administered to a patient. However, carriers can also serve to further improve the dispersibility of the powder in a powder dispersing device, ensuring more efficient and reproducible administration of the active ingredient and improving the handling characteristics of the active ingredient (e.g., flowability and consistency) to facilitate preparation and filling of the powder. In particular, excipients can often improve the physical and chemical stability of particles to further minimize residual moisture content and inhibit moisture uptake, and to improve particle size, aggregation, surface properties (i.e., puckering), ease of inhalation, and targeting the resulting particles deep into the lungs.

These excipients, if present, are typically present in the composition in amounts of about 1-50% by weight and include, but are not limited to, proteins, peptides, amino acids, and carbohydrates (e.g., sugars, including monosaccharides, di-, tri-, tetra- and oligosaccharides; derivatized sugars such as alditols, aldonic acids, esterified sugars etc / and polysaccharides or sugar polymers), which may be present alone or in combination. Exemplary protein excipients include serum albumin such as human serum albumin (HSA), recombinant human albumin (rHA), gelatin, casein, etc. Representative amino acid / polypeptide components that may also have a buffering effect, including

These include alanine, glycine, arginine, betaine, histidine, glutamic acid, aspartic acid, cysteine, lysine, leucine, isoleucine, valine, methionine, phenylalanine, aspartame, di- and tripeptides, such as trileucine excipients, etc. for use according to the invention include, for example, monosaccharides such as fructose, maltose, galactose, glucose, D-mannose, sorbose; disaccharides such as lactose, sucrose, trehalose, cellobiose and the like; polysaccharides such as raffinose, melezitose etc .; and alditols such as mannitol, xylitol, maltitol, lactitol, xylitol, sorbitol (glucitol), myo-inositol, etc.

The compositions may also contain a buffer or a pH adjuster. Representative buffers include organic acid salts such as salts of citric acid, ascorbic acid, gluconic acid, carbonic acid, tartaric acid, succinic acid, acetic acid, or phthalic acid; Tris, tromethamine hydrochloride or phosphate buffers. The compositions may contain additional excipients / adjuvants such as Ficolls (polymeric sugar), flavors, antibacterials, sweeteners, antioxidants, antistatic agents, surfactants (e.g. polysorbates such as "TWEEN 20 and" TWEEN 80). and chelating agents (e.g., EDTA). Other pharmaceutical excipients and / or adjuvants suitable for use in the matrix compositions described herein are listed in "Remington: The Science & Practice of Pharmacy, 4th Ed." 19, Williams & Williams, (1995) and in "Physician's Desk Reference, ed. 52, Medical Economics, Montvale, NJ (1998). Preferred excipients for use in the formulations described herein are mannitol, raffinose and sodium citrate, leucine, isoleucine, valine, sucrose, raffinose, trileucin and mannitol.

Dry powder formulations of the active ingredient are prepared by spray drying under conditions which permit the production of a substantially amorphous powder. Spray drying of the formulations is carried out, for example, as generally described in "Spray Drying Handbook, 2nd Ed." 5, K. Masters, John Wiley & Sons, Inc., NY, NY (1991) and WO 97/41833.

Solutions, emulsions or suspensions are prepared containing the active ingredient, a hygroscopic growth inhibitor and optionally other excipients. Spray drying solutions or suspensions will typically contain from about 0.1 to 10% by weight per volume solids. Solutions usually have a pH of about 3-9 and this will depend on the effect of the pH on the stability of the active ingredient. PH readings close to neutral are advantageous because such pH values can help maintain the physiological compatibility of the powder when dissolved in the lungs. The pre-spray-dried preparations can optionally contain additional water-miscible solvents such as alcohols or acetone. Representative alcohols are lower alcohols such as methanol, ethanol, propanol, isopropanol and the like. The resulting solutions will typically contain a concentration of the active ingredient from 0.01% (w / v) to about 2% (w / v). typically 0.1-1% (w / v).

The solutions are then spray dried in an ordinary spray dryer, such as commercially available from suppliers such as Niro A / S (Denmark), Buchi (Switzerland) etc., to obtain a stable, dry powder. Optimum conditions for spray drying the formulations will depend on the ingredients of the formulation and are usually experimentally determined. The gas used to spray the dry substance is usually air, although inert gases such as nitrogen or argon are also suitable. Moreover, the inlet and outlet temperatures of the gas used to dry the spray-dried substance are such that it does not cause deactivation / decomposition of the active substance in the spray-dried substance. Such temperature is usually experimentally determined, although generally the inlet temperature will be about 50-200 ° C while the outlet temperature will be about 30-150 ° C.

Alternatively, the dry powders may be prepared by freeze drying, vacuum drying, freeze spray drying, supercritical liquid processing, or other evaporative drying methods. In some cases, it may be desirable to produce a dry powder formulation in a mold exhibiting improved handling / processing characteristics, e.g., reduced static charge, better flow, less caking, etc., by preparing a composition composed of fine particle aggregates, i.e., matrix aggregates or agglomerates as described above. dry powder particles, these aggregates being readily disintegrated into fine powder particles upon administration to the lungs as described in U.S. Patent No. 5,654,007. Alternatively, the powders may be prepared by agglomerating the powder ingredients, sieving the material to form agglomerates, beads to form a more spherical agglomerate and sieving to obtain a uniform product size as described in WO 95/09616. Dry powders can also be prepared by mixing, grinding, sieving or jet milling the ingredients of the formulation as a dry powder. The resulting powder is usually substantially amorphous.

The dry powders are preferably kept under dry conditions (i.e., relatively low humidity) during manufacture, processing and storage.

The powder particles are able to maintain an aerodynamic diameter below 3 mm when administered to the alveoli. As can be seen from Example 1, the powders without the hygroscopic growth inhibitor and with an initial MMAD of 3.5 mm performed as powders with a MMAD of 5-6 mm. Calculations showed that with an equilibrium in the lungs, the MMAD of the powder particles will increase to 9 mm. From these data, it was found that the incorporation of a hygroscopic growth inhibitor into the powder formulations containing the particles according to the invention was effective in significantly reducing the rate and / or degree of hygroscopic growth of dry powder particles, thereby increasing not only the bioavailability of the active ingredient contained in the powder particles, but also the dispersibility of such preparations.

For powders composed of the particles of the invention, the MMAD of the particles will in most cases be less than about 3 mm prior to pulmonary administration. Typically the particles will grow to some extent upon pulmonary administration, although less than without a hygroscopic growth inhibitor, and will typically have a hygroscopic growth ratio of less than about 2.5, preferably less than about 2.0, even more preferably from about 1.5 to about 1.5. 2.0 and most preferably less than 1.5. The hygroscopic growth ratio can be determined experimentally by comparing the MMAD of the powder particles determined under ambient conditions with the MMAD determined under simulated lung conditions in an environmental chamber (MMAD lung / MMADenvironment). Alternatively, the MMAD of the particles under pulmonary conditions can be calculated as follows. First, the isotonicity of each of the components is determined based on the molecular weight value of all the components of the particles. Then these isotonicity values are added to determine the isotonicity of the particle. From this value, the volume of solution required to make isotonic is calculated; this volume is taken to be the volume of the sphere. From this sphere volume, the diameter of the sphere is calculated and the calculated MMAD of the particle under lung conditions is determined. The thus calculated MMAD can then be used to determine the hygroscopic growth ratio as described above.

The moisture uptake characteristics of the particles are typically determined in moisture sorption experiments. Moisture sorption data for powders can be determined by a number of methods such as moisture sorption balance or thermal activity monitoring (TAM). Moisture sorption balances are determined by measuring the loss or weight gain as a function of increasing or decreasing relative humidity at a constant temperature. The carrier gas introduced at a known relative humidity is produced by mixing wet and dry gas streams. Then this gas is applied to the sample placed in a non-hygroscopic vessel mounted on a microbalance. Depending on the morphology of the sample, it can absorb, adsorb or desorb moisture. This sorption is detected on the microbalance as a mass gain or loss. A computer program is used to collect data points (time, temperature, relative humidity and mass in general) over the duration of the experiment and at user-defined equilibrium points.

The powders of the particles of the invention may also be characterized by the sorption index, SI, which is the sum of the percentage weight gain of the powder determined at 10%, 20%, 30% and 40% relative humidity, divided by 4. The sorption index is determined using a gravimetric sorption analyzer. such as DVS-1000, manufactured by Surface Measurements Systems (London, UK), or by a moisture balance using an instrument such as the MB 300G, manufactured by VTI Corporation (Hialeah, FL). Powders will typically have a sorption index less than about 7.5, preferably less than about 7.0, more preferably less than about 6.5, and most preferably less than 6.0. Powders showing such SI values are presented in Example 2.

Preferred powders are those that take up water slowly, i.e., less than about 0.75% moisture per unit relative humidity, preferably less than about 0.50% moisture per unit relative humidity, more preferably less than about 0.35% moisture per unit humidity. relative humidity, and most preferably less than about 0.25% moisture per unit relative humidity (e.g., see Fig. 1). According to another measure, the particles absorb less than about 60% moisture (wt), preferably less than 30% moisture, more preferably less than 25% moisture, even more preferably less than 20% moisture, and most preferably about 10-20% water by weight under humid conditions at 80% relative humidity. . Figures 1 and 2 show how the powders containing the hygroscopic growth inhibitor show, compared to the HGI-free powder formulations, a reduced water uptake rate (indicated by lower slopes compared to the control formulation) and a lower overall degree of moisture uptake.

PL 195 574 B1

According to Fig. 1, under 80% relative humidity, the spray-dried control powder containing 20% insulin, 59% sodium citrate, 18% mannitol and 2.6% glycine absorbed 60% by weight of moisture, while under the same conditions the spray-dried dextran. hydroxypropyl methylcellulose, hydroxypropyl-b-cyclodextrin, and hydroxyethyl starch absorbed 24%, 16%, 16%, and 24% moisture, respectively, illustrating the excellent ability of these substances to inhibit hygroscopic growth. Similarly, according to Fig. 2, under 80% relative humidity, the control absorbed 60% moisture, while under the same conditions spray-dried powders containing 20% insulin, 40% hydroxyethyl starch, 2.6% glycine, 18% mannitol, 19% citrate. sodium and 100% hydroxyethyl starch absorbed 50% and 24% moisture, respectively. Moreover, in both figures, the water uptake rate was substantially slower for the HGI substances compared to the control substances.

The powders of the present invention may also be characterized by retaining good dispersibility when exposed to hot and humid conditions, such as those of the lung environment. These powders will generally exhibit a drop in Dose Emitted (ED) at 32 ° C and 95% RH (compared to ED at ambient conditions) of no more than about 30% (meaning an EDmotage difference of 30 or less) , preferably no more than about 20-25%, more preferably no more than 15%, and most preferably no more than about 10%.

Example 2 illustrates powder formulations whose EDs, when assessed in an environmental chamber, only decrease by about 10-15% (60% maltodextrin formulations). Powder formulations containing 60% hydroxyethyl starch also showed good ED under lung conditions. As can be seen from the data in Table 1, increasing the amount of hydroxyethyl starch from 40% to 60% (samples 2/3 versus 4/5) was effective in reducing the decrease in ED in the environmental chamber. On average, these formulations showed an ED decrease of about 20% under pulmonary conditions, while maintaining an ED value of about 55%.

The emitted dose (ED) of HGI-containing powders under ambient conditions is greater than 30%, and usually greater than 40%. More preferably the emitted dose of the powders is greater than 50% and often greater than 60%. Powders usually have a high proportion of small aerosol particles and are therefore extremely effective when administered as an aerosol as they (i) reach the alveolar region of the lungs, (ii) diffuse into the interstitial tissue, and (iii) pass further into the bloodstream through the endothelium.

The dry powders will generally have a total moisture content at ambient conditions of less than about 10% by weight, usually less than about 5% by weight, and preferably less than about 3% by weight. These low moisture solids tend to be more stable than corresponding high moisture solids.

Dry powder formulations containing HGI are preferably administered using a suitable dry powder inhaler (DPI), an inhalation device that uses the patient's inspiration to transport the dry powder drug to the lungs. Preferred are Inhale Therapeutic Systems dry powder inhalers as described in U.S. Patent Nos. 5,458,135, 5,740,794, and 5,785,049.

In this type of device, the dry powder is contained in a container having a perforated bottom or other access surface, preferably a blister pack or cartridge, the container may contain a single dose or multiple unit doses. Convenient methods of filling a series of cavities with measured doses of dry powder medicament are described in, e.g., Parks, D.J. and others in WO 97/41031, (1997).

Also suitable for delivering dry powders are dry powder inhalers of the type described in US Patent Nos. 3,996,950 and 4,013,075, wherein a measured dose of the dry powder for administration to a patient is contained in a hard gelatin capsule.

Other devices for dispersing dry powder for pulmonary administration are those described, for example, in European Patent Nos. 129985, 472598 and 467172 and in US Patent No. 5,522,385. Inhalers such as Astra are also suitable for administering matrix dry powders. Draco "TURBUHALER. This type of device is described in detail in U.S. Patent Nos. 4,668,218, 4,667,668 and 4,805,811. Apparatus employing a plunger providing an air flow entraining the drug powdered, lifting the drug from the support sieve after air is passed through the sieve or the air with the drug is also suitable. in the form of a powder in the mixing chamber for delivering the powder to a patient through the mouthpiece of the device as described in US Patent No. 5,388,572.

HGI-containing dry powders can also be administered using a metered dose inhaler (MDI) containing a solution or suspension of the drug in a pharmaceutically inert liquid propellant, e.g., a chlorofluorocarbon or a fluorocarbon, as described in U.S. Patent Nos. 5,320,094 and 5,672,581.

Prior to use, HGI-containing dry powders are typically stored under ambient conditions, and preferably at a temperature of about 25 ° C or less, with a relative humidity (RH) of about 30 to 60%. More favorable relative humidity conditions, for example, less than about 30%, may be achieved by including the dehydrating agent in the outer packaging of the dosage form. The inhalable dry powders not only have good aerosolization characteristics, but also good stability.

When aerosolized for direct pulmonary administration, the active ingredient contained in dry powder formulations will show increased bioavailability in the lung due to the presence of HGI in the powder particles, allowing more inhaled particles to reach deep into the lungs without first settling in the upper airways due to hygroscopic growth. Such HGI-containing formulations thus allow for the administration of smaller amounts of drug per unit dose and may even eliminate the need for multiple inhalations per day. In addition, the presence of HGI provides improved stability to powder formulations by reducing or preventing moisture uptake, which increases the shelf life and transport stability of the dry powder formulations.

The figures of the drawing are described below.

Figure 1 shows the moisture sorption profiles of various spray-dried powder formulations, with moisture uptake (% by weight) on the vertical axis and% relative humidity on the horizontal axis. (Circles: 20% insulin, 59% sodium citrate, 18% mannitol, 2.6% glycine; Squares: 100% dextran (10K); Diamonds: 100% hydroxypropylmethylcellulose; X: 100% hydroxypropyl-b-cyclodextrin, and ±: 100% low molecular weight hydroxyethyl starch);

Figure 2 shows the moisture sorption profiles for 3 different spray-dried powder formulations. (Circles: 20% insulin, 59% sodium citrate, 18% mannitol, 2.6% glycine; Squares: 20% insulin, 2.6% glycine, 40% hydroxyethyl starch, 18% mannitol, 19% sodium citrate; Diamonds: 100 % hydroxyethyl starch). Adding one or more HGI to a particular formulation reduces its moisture sorption;

Figure 3 shows the TAM (thermal activity monitoring) results for various dry insulin powder formulations, illustrating the effectiveness of two exemplary hygroscopic growth inhibitors in significantly reducing the hydration capacity of these powders;

Figure 4 is a plot of moisture sorption for the three spray dried formulations illustrating the effectiveness of formulations containing a hygroscopic growth inhibitor in reducing both the rate and total water uptake. (Circles: 20% insulin, 59% sodium citrate, 18% mannitol, 2.6% glycine; Squares: 100% spray-dried hydroxypropyl-b-cyclodextrin; Diamonds: 20% insulin, 20% leucine, 50% b- butyl sulfonyl ether cyclodextrins, 10% sodium citrate); and

Figure 5 is a moisture sorption plot that compared five different spray dried formulations. The graph further illustrates the ability of HGI-containing formulations to significantly reduce water rate and uptake compared to non-HGI formulations. (Wheels: 20% insulin, 20% leucine, 50% hydroxyethyl starch, 10% sodium citrate; Squares: 20% insulin, 5% leucine, 50% hydroxyethyl starch, 25% sodium citrate: Diamonds: 100% hydroxyethyl starch; X: 20% insulin , 59% sodium citrate, 18% mannitol, 2.6% glycine; +: 20% leucine, 50% hydroxyethyl starch, 30% sodium citrate).

The following examples illustrate the invention.

Materials and methodology

Salmon calcitonin (sCalcitonin) was purchased from Bach (Torrance, CA). Human Serum Albumin (HSA) was purchased from Miles Inc. (Kankakee, IL). Sodium citrate dihydrate was obtained from J.T. Baker (Phillipsburg, NJ). L, α-dipalmitoylphosphatidylcholine (DPPC) was obtained from Avanti Polar Lipids, Alabama.

PL 195 574 B1

P r z k ł a d 1

Particles containing the following active ingredient were prepared to test moisture uptake and hygroscopic growth properties.

A. Manufacture of powder

Powdered salmon calcitonin was prepared as follows. Bulk sCalcitonin was dissolved in sodium citrate buffer containing mannitol and HSA to give an aqueous solution with a final solids concentration of 7.5 mg / ml and pH 6.7 0.3. The solution was then filtered through a 0.22 mm filter and then spray dried using a Buchi 190 miniature spray dryer (Buchi Labortechnik AG, Meierseggstrasse, Switzerland). The spray dryer was operated with an inlet temperature of 110-120 ° C, a liquid flow rate of 5 ml / min, and an outlet temperature of 70-80 ° C to give a fine white amorphous powder.

Similarly, powders containing DPPC hygroscopic growth inhibitors (HGI), cyclodextrin, hydroxyethyl starch, dextran, dextranomer, maltodextran, hydroxypropyl cellulose, hydroxypropyl methyl cellulose and cellulose ethyl hydroxyethyl ether were prepared.

The composition of the powder without HGI is 5% sCalcitonin / 6.25% HSA / 73.75% mannitol / 15% citrate (by weight). The HGI powder contains the same relative amounts of sCalcitonin / HSA / mannitol / citrate, but also contains from about 10% to 90% by weight of the hygroscopic growth inhibitor.

The resulting powders are stored in well-covered containers in a dry environment (<10% RH) prior to analysis for hygroscopic growth.

B. Powder analysis

The particle size distribution of the sCalcitonin powder was measured using a liquid sediment centrifuge on a Horiba CAPA-700 particle size analyzer, after dispersing the powders in Sedisperse A-11 (Micrometrics, Norcross, GA).

The moisture content of the sCalcitonin powder was measured by the Karl Fischer method using a Mitsubishi CA-06 moisture meter.

The aerosol particle size distribution was determined using a cascade impact mill (Graseby Andersen, Smyrna, GA) at a flow rate of 28 L / min, excluding powder loss in the inlet manifold and stage 0 flow plate.

Emitted doses (ED) were determined using an Inhale Therapeutic Systems aerosol device, similar to that described in WO96 / 09085. The emitted dose is defined as the percentage of the nominal dose contained in the blister pack reaching the mouthpiece of the aerosol device and captured on a glass fiber filter (Gelman, 47 mm diameter) through which air (30 l / min) was extracted for 2.5 seconds after the device was started . The ED is calculated by dividing the weight of the powder collected on the filter by the weight of the powder in the blister wrap.

The ED of 5% of the sCalcitonin powders was 52.6-53.9%.

The MMAD of the 5% sCalcitonin powders was about 3.5-3.6 mm.

This analysis was performed similarly for sCalcitonin powders containing DPPC.

C. Particle Growth

The following study was performed to test the bioavailability of sCalcitonin formulations delivered to the lungs as a dry powder spray.

SCalcitonin particles without HGI were administered to 16 healthy volunteers. Each patient received a dose of a dry powder spray. The aerosol dose was approximately 2.5 mg of a powder containing approximately 750 IU (125 mg) of salmon calcitonin labeled with ^99m Tc pertechnetan (10 MBq). The particles were aerosolized using the Inhale Therapeutic Systems aerosol generating equipment described above.

The dose of sCalcitonin delivered to the lung and periphery of the lung (deep into the lung) was determined by a modified known method using a gamma camera. Quantitative evaluation of sCalcitonin reaching the circulatory system was obtained by radioimmunoassay of human serum samples collected 6 hours after administration ("Ultra-Sensitive Radioimmunoassay kit for the Quantitative Radioimmunoassay for the Quantitative Determination of salmon calcitonin in serum and Plasma, Diagnostic Systems Laboratories Inc.)

Bioavailability was determined by comparing the dose-adjusted AUC (area under the curve) estimates using the peripheral (alveolar) dose. Simple trapezoidal integration was used to determine AUC. Relative bioavailability was determined for subcutaneous injection. Statistical analysis of the gamma camera deposition data and the relative bioavailability data was performed

Using the Wilcoxon signed-rank pairs of observations test. The Wilcoxon test is a non-parametric test suitable for small samples. A p value of £ 0.05 was considered significant.

The size distribution of the powder without HGI before and after radiolabelling was substantially unchanged. When examining areas of spatial deposition patterns after inhalation, 21.6% of the inhaled dose of powder was found to have reached the rim of the lung (45.6% had reached the entire lung, including the rim of the lung), while the loss in the mouth and oropharynx was 54.4 %.

The bioavailability of salmon calcitonin powder with respect to subcutaneous injection was 28.0% of the dose delivered to the periphery of the lung. Despite the value of 3.5 MMAD obtained for the aerosol particle size distribution, this powder acted as a powder with an MMAD of 5-6 mm. This can be attributed to the hygroscopic growth of the particles as they pass through the respiratory tract due to the hygroscopic nature of the formulation.

The confirmation of this mechanism was obtained by calculating the aerodynamic equilibrium increase ratio for the preparation, which was 2.53. This ratio indicates that under airway conditions the particles grow, and at equilibrium from an initial MMAD value of 3.5 mm the aerosol particles grow to 9 mm MMAD (i.e., the particles grow 2.53 times their original aerodynamic diameter). The equilibrium growth ratios are determined by calculating the solids concentration (powder to water ratio) at which the aqueous solution of the powder becomes isotonic, i.e. the concentration at which the liquid droplet equilibrates in the lungs, which then allows the MMAD of the isotonic droplet to be calculated. The growth ratio is:

^{MMAD of} isotonic droplet / ^MMAD of surrounding powder particles

Thus, sCalcitonin powders which retain a MMAD of 3.0 mm when administered to alveoli are prepared by guiding one or more HGI into particles at a concentration of about 1090%, and particularly 10, 20, 30, 40, 50, 60, 70, 80 and 90% by weight of HGI. The resulting powders are then tested as described above to determine their hygroscopic growth, if any, upon exposure to the environmental conditions of the lungs. The powders according to the invention are those showing inhibition or reduction of hygroscopic growth, in particular those which allow a particle size distribution to be less than 3.0 mm MMAD when administered to the periphery of the lung, which increases peripheral deposition and increases the lung bioavailability of the lung delivered active ingredient.

P r z k ł a d 2

Powder measurements in an environmental chamber

Spray dried powders containing one or more hygroscopic growth inhibitors were prepared as described in Example 1. The relative weight percentages of the powder ingredients are shown in Table 1.

To evaluate the hygroscopic behavior of the aerosol powders, the dry inhalation powders were placed in an environmental chamber (Enviro-Chamber) that simulates physiological conditions in human lungs (32 ° C and 95% RH). The chamber was monitored with a pre-calibrated humidity and temperature probe (Digi-sense). Pre-collected data from this pre-calibrated probe showed that a relative humidity of 95% and a temperature of 32 ° C existed in the Enviro-Chamber for an extended period of time.

The emitted dose and particle size were measured under standard (24 ° C and 40%) and humid conditions (32 ° C and> 95% relative humidity). Sampling under standard conditions was performed inside an environmental chamber with the system off. Data collected under standard conditions was used as a baseline control. Membrane filters (47 mm) were used for ED collection and an Andersen cascade impact mill for particle size distribution measurements.

PL 195 574 B1

T a b e l a 1

Sample No. Lot no Recipe ED, n = 28 environment ED chamber E Indicator sorption 1 R98403 60% maltodextrin 20% insulin 2.6% glycine 4.3% mannitol 13.09% citrate 0.013% citric acid, pH 7.3 76.94 67.12 5.3 2 R98403 same 78.51 65.31 5.3 3 R98414 40% HES-hmw 20% insulin 2.6% glycine 10% mannitol 27.4% citrate pH 7.3 72.63 47.52 6.4 4 R98414 same 77.23 49.39 6.4 5 R99041 60% HES-hmw 20% insulin 2.6% glycine 4.3% mannitol 13.09% citrate 0.013% citric acid pH 7.3 75.83 54.55 6 R99041 same 74.23 55.48

* HES-hmw = hydroxyethyl starch

The results in Table 1 show that the HGI containing powders are highly dispersible under ambient conditions and retain good dispersibility under simulated lung conditions. The results also show how formulations can be optimized by selecting the amount of HGI, as seen for samples 3/4 compared to samples 5/6, where increasing the percentage of hydroxyethyl starch from 40% to 60% was effective in reducing the drop in ED under high humidity conditions (EDenvironment - EDlung). This is illustrated by the resistance of HGI-containing powders to water uptake and their ability to be free-flowing, even under extremely humid conditions.

The MMAD of R98403 powder (samples 1 and 2 above) was determined under moderate temperature and humidity conditions (21.1 ° C and 40% RH). The results are given in Table 2.

T a b e l a 2

Fill weight (mg) (dosage form) MMAD (mm) % <5 mm % <3.3 mm 5 2.9 84 59 5 2.9 84 59 2 2.3 96 77 2 2.4 94 74

As is evident from the above results, this exemplary powder retains a low MMAD even under conditions of elevated temperature and humidity.

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The spray dried powders were prepared as described in Example 1. Moisture sorption profiles were determined for these spray dried powders containing HGI using a gravimetric sorption analyzer, DVS-1, manufactured by VTI Corporation- (Hialeah, FL). The spray dried powders had the following composition (weight percent).

A. 20% insulin, 59% sodium citrate, 18% mannitol, 2.6% glycine

B. 100% dextran

C. 100% hydroxypropyl methylcellulose

D. 100% hydroxypropyl-b-cyclodextrin

E. 100% hydroxyethyl starch (low molecular weight equal to 200,000)

F. 20% insulin, 40% hydroxyethyl starch, 2.6% glycine, 18% mannitol, 19% sodium citrate

G. 20% insulin, 20% leucine, 50% b-cyclodextrin sulfonyl butyl ether, 10% sodium citrate.

H. 20% insulin, 20% leucine, 50% hydroxyethyl starch, 10% sodium citrate

I. 20% insulin, 5% leucine, 50% hydroxyethyl starch, 25% sodium citrate

J. 20% leucine, 50% hydroxyethyl starch, 30% sodium citrate

The moisture sorption profiles for powders A, B, C, D and E are shown graphically in Fig. 1.

The moisture sorption profiles for powders A, F and E are shown in Fig. 2.

The moisture sorption profiles for powders A, D and G are shown in Fig. 4.

The moisture sorption profiles for the powders H, I, E, A and J are shown in Fig. 5.

As can be seen from each of the figures, when the addition of a hygroscopic growth inhibitor to a particular formulation effectively and noticeably reduced its moisture sorption properties, it thereby reduced the hygroscopic growth of the particles as they migrated through the airways into the lungs.

P r z k ł a d 4

The hydration properties of various spray-dried powder insulin formulations were compared by TAM (thermal activity monitoring) using the Thermal Activity Monitor, Model 2277 (Thermometric, Sweden). The run conditions were as follows: ramp mode using RH perfusion units; Relative humidity is ramped up steadily from 0% to 90% at a rate of 3% per hour at 25 ° C with a nitrogen flow of 1.48 Ncm ³ / min. The composition of the dry powders used was as follows.

A. 20% insulin, 59% sodium citrate, 18% mannitol, 2.6% glycine

B. 60% (by weight) insulin, 2.6% glycine, 10% mannitol, 27.4% sodium citrate, 2.6% glycine.

C. 40% HES-hmw, 20% insulin, 2.6% glycine, 10% mannitol, 27.4% citrate

D. 60% maltodextrin, 20% insulin, 2.6% glycine, 4.3% mannitol, 13.09% citrate, 0.13% citric acid.

The TAM results for each formulation are shown in Figure 3. From Figure 3, it can be seen that the incorporation of HGI into the 20% insulin formulations resulted in a significant decrease in the degree and rate of moisture absorption compared to the HGI-free 20% insulin formulation, demonstrating the efficacy of these examples. HGI in reducing the degree of hygroscopic growth of these particles.

Claims (52)

Patent claims Particles for administering the active ingredient to the alveoli of a human patient, comprising the active ingredient and at least about 40% by weight of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether , hydroxyethyl starch, dextranomer, and maltodextrins, which hygroscopic growth inhibitor is incorporated into the particles, wherein the particles exhibit a dose emitted drop under simulated lung conditions of no greater than about 25%. 2. Particles according to claim 1 The method of claim 1, wherein the hygroscopic growth inhibitor is selected from the group consisting of hydroxyethyl starch, dextranomer and maltodextrins. 3. Particles according to claim 1 The method of claim 1, wherein the hygroscopic growth inhibitor is selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin and b-cyclodextrin sulfobutyl ether. 4. Particles according to claim 1 The method of claim 1, wherein the hygroscopic growth inhibitor is hydroxyethyl starch. PL 195 574 B1 5. Particles according to claim 1 The method of claim 1, wherein the hygroscopic growth inhibitor is present in an amount sufficient for the particles to exhibit a moisture uptake rate of no greater than about 0.50% as a function of relative humidity. 6. Particles according to claim 1 The method of claim 1, wherein the hygroscopic growth inhibitor is present in an amount sufficient for the particles to exhibit a total water uptake of no greater than about 30% by weight at a relative humidity of 80%. 7. Particles according to claim 1 The method of claim 1, characterized in that they have an ambient dose emitted at least 60%. 8. Particles according to claim 1 The composition of claim 1, containing about 40-99% by weight of the hygroscopic growth inhibitor. 9. Particles according to claim 1 The method of claim 8, containing about 40-60% by weight of the hygroscopic growth inhibitor. 10. Particles according to claim 1 The method of claim 1, wherein more than 20% of the nominal dose is deposited deep into the lungs when administered to the lungs. 11. The particles according to claim 1 The method of claim 1, wherein the hygroscopic growth inhibitor is effective to increase the bioavailability of the active ingredient when administered to the lungs by at least 5% compared to the bioavailability observed with the active ingredient contained in the same particles without the hygroscopic growth inhibitor and delivered to the lungs. 12. Particles as claimed in claim 1, A method according to claim 1, characterized in that the active ingredient is a protein or a polypeptide. 13. Particles as claimed in claim 1, The pharmaceutical composition according to claim 12, characterized in that the active ingredient is insulin. 14. Particles as claimed in claim 1, The pharmaceutical composition according to claim 12, characterized in that the active ingredient is calcitonin. 15. Particles as claimed in claim 1, 2. The process of claim 1, wherein they have been spray-dried. 16. Particles as claimed in claim 1, 2. A formulation as claimed in claim 1 in the form of an aerosol for use in administering the active ingredient to the lungs of a human patient. 17. Particles as claimed in claim 1, The method of claim 1, for use in administering the active ingredient to the lungs of a human patient using a dry powder inhaler. 18. Particles for administering the active ingredient to the alveoli of a human patient, comprising the active ingredient and at least about 40% by weight of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether , hydroxyethyl starch, dextranomer, and maltodextrins incorporated into the particles, wherein the particles have a sorption index less than about 6.5. 19. Particles according to claim 1 The process of claim 18, wherein the hygroscopic growth inhibitor is selected from the group consisting of hydroxyethyl starch, dextranomer and maltodextrins. 20. Particles as claimed in claim 1, The process of claim 18, wherein the hygroscopic growth inhibitor is selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin and b-cyclodextrin sulfobutyl ether. 21. Particles as claimed in claim 1, The process of claim 18, wherein the hygroscopic growth inhibitor is hydroxyethyl starch. 22. Particles as claimed in claim 1, The method of claim 18, characterized in that they have an ambient dose emitted at least 60%. 23. Particles according to claim 1 The composition of claim 18, comprising about 40-99% by weight of the hygroscopic growth inhibitor. 24. Particles as claimed in claim 24 The composition of claim 23, comprising about 40-60% by weight of the hygroscopic growth inhibitor. 25. Particles as claimed in claim 1, The method of claim 18, wherein more than 20% of the nominal dose is deposited deep into the lungs when administered to the lungs. 26. Particles as claimed in claim 1, The method of claim 18, comprising a hygroscopic growth inhibitor which is effective to increase the bioavailability of the active ingredient when administered to the lungs by at least 5% compared to the bioavailability observed with the active ingredient contained in the same particles not containing the hygroscopic growth inhibitor and delivered to the lungs. 27. Particles as claimed in claim 1, The pharmaceutical composition according to claim 18, characterized in that the active ingredient is a protein or a polypeptide. 28. Particles as claimed in claim 28 27. A preparation according to the invention, characterized in that the active ingredient is insulin. 29. Particles as claimed in claim 1 27. A method according to claim 27, characterized in that the active ingredient is calcitonin. 30. Particles as claimed in claim 1, 18. The apparatus of claim 18, wherein the apparatus has been spray dried. PL 195 574 B1 31. Particles as claimed in claim 1, The method of claim 18, in the form of an aerosol for use in administering the active ingredient to the lungs of a human patient. 32. Particles as claimed in claim 1, The method of claim 18 for use in administering the active ingredient to the lungs of a human patient using a dry powder inhaler. 33. Particles for administering the active ingredient to the alveoli of a human patient, comprising the active ingredient and at least about 40% by weight of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether , hydroxyethyl starch, dextranomer, and maltodextrins, incorporated into the particles, which particles maintain an aerosol particle size distribution below 3 mm MMAD when administered to the alveoli. 34. Particles as claimed in claim 1, The method of claim 33, wherein the aerosol is for use in administering the active ingredient to the lungs of a human patient. 35. Particles according to claim 35 The method of claim 33 for administering the active ingredient to the lungs of a human patient using a dry powder inhaler. 36. A process for the preparation of particles for administering an active ingredient to the alveoli of a human patient comprising preparing a mixture of (i) at least about 40% by weight (solid) of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b, cyclodextrin, b-cyclodextrin sulfobutyl ether, hydroxyethyl starch, dextranomer and maltodextrins, (ii) an active ingredient, and (iii) a solvent; spray-drying this mixture to obtain homogeneous particles of the hygroscopic growth inhibitor and the active ingredient, wherein the particles exhibit a drop in dose emitted under simulated lung conditions of no more than about 25%. 37. The method according to p. The process of claim 36, wherein the hygroscopic growth inhibitor is selected from the group consisting of hydroxyethyl starch, dextranomer and maltodextrins. 38. The method according to p. The process of claim 36 wherein the hygroscopic growth inhibitor is used is selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin and b-cyclodextrin sulfobutyl ether. 39. The method of p. The process of claim 36, wherein the hygroscopic growth inhibitor is hydroxyethyl starch. 40. The method according to p. The process of claim 36, wherein the solvent is water. 41. The method according to p. The method of claim 36, wherein the homogeneous particles contain about 40-99% by weight of the hygroscopic growth inhibitor. 42. The method of p. The method of claim 41, wherein the homogeneous particles contain about 40-60% by weight of the hygroscopic growth inhibitor. 43. The method according to p. A method according to claim 36, characterized in that the active ingredient is a protein or a polypeptide. 44. The method of p. 43. A method according to claim 43, characterized in that the active ingredient is insulin. 45. The method of p. A process as claimed in 43, characterized in that the active ingredient is calcitonin. 46. Use of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether, hydroxyethyl starch, dextranomer and maltodextrins to prepare particles which contain an active ingredient as defined in claim 1. For administering the active ingredient to the lungs of a human patient by inhalation of the aerosolized active particles. 47. Use according to claim 1 46, wherein the active ingredient is administered using a dry powder inhaler. 48. Use of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether, hydroxyethyl starch, dextranomer and maltodextrins to prepare particles which contain an active ingredient as defined in claim 1. For administering the active ingredient to the lungs of a human patient by inhalation of the aerosolized active particles. 49. 48, wherein the active ingredient is administered using a dry powder inhaler. 50. Use of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether, hydroxyethyl B, dextranomer and maltodextrins for the preparation of particles which contain an active ingredient as defined in claim 1 33 for administering the active ingredient to the lungs of a human patient by inhalation of the aerosolized active particles. 51. Use according to claim 1 50, wherein the active ingredient is administered using a dry powder inhaler. 52. Use of a hygroscopic growth inhibitor selected from the group consisting of b-cyclodextrin, hydroxypropyl-b-cyclodextrin, b-cyclodextrin sulfobutyl ether, hydroxyethyl starch, dextranomer and maltodextrins for the preparation of particles for lung administration of the active ingredient and deposition into the depth of the lungs by introduction of at least about 40% by weight of this hygroscopic growth inhibitor for inhalable dry powder particles containing the active ingredient such that after aerosolization and inhalation of the particles, at least 20% of the nominal dose is deposited deep into the lungs.