FI106926B - Process for forming a composition which is released over a long period - Google Patents

Description

106926

METHOD FOR MAKING A LONG-TERM COMPOSITION

The present invention relates to a process for forming a sustained release composition comprising octreotide or a salt or derivative thereof in a biodegradable and biocompatible polymeric carrier.

Often, peptide drugs have poor bioavailability after oral or gastrointestinal administration, e.g. due to their short biological half-life due to their metabolic instability. Additionally, when administered orally or nasally, they often have poor absorption through the mucous membranes. It is difficult to achieve a therapeutically relevant concentration in the blood over a longer period. It has been proposed to administer peptide drugs externally as a depot composition in a biodegradable polymer, for example as microparticles or implants, allowing for their sustained release after a residence time in a polymer that protects the peptide against the enzymatic and hydrolytic effects of the biological medium.

Although some gastrointestinal peptide drug depot formulations in the polymer in the form of microparticles or implants are known, in practice, very few peptide release profiles are achieved. In order <to achieve continuous peptide release such that. ···. Serum levels of the drug are therapeutically active and special measures must be taken to avoid excessive drug serum concentrations that cause unwanted pharmacological side reactions.

The release pattern of the peptide drug depends on a number of factors, for example the type of peptide and, for example, its presence in free or other forms, for example as a salt, which may affect its water solubility. Another important factor is the choice of polymer from the extensive list of possibilities described in the literature.

Each type of polymer has a specific rate of biodegradation. Free carboxyl groups may be formed which affect the pH in the polymer and thus contribute to the water solubility of the peptide and hence its release pattern.

Other factors that may influence the release pattern of the depot composition include the concentration of the drug in its polymeric carrier, its mode of distribution in the polymer, particle size, and its shape in the implant. In addition, the composition is affected by its location in the affected body.

To date, the somatostatin composition in sustained release form for non-gastrointestinal administration has not been marketed, perhaps due to the lack of a composition with a satisfactory serum level profile.

Polymeric polymer compositions are known in the art and are designed to provide sustained, sustained, or delayed drug release.

U.S. Patent No. 3,773,919 comprises controlled release drug release compositions wherein the drug, for example, a water-soluble peptide, is dispersed in a biodegradable and biocompatible linear polylactide or polylactide co-glycolide dipolymer.

However, drug release models have not been described and there is no reference to somatostatin. U.S. Patent · ... “4293539 describes bactericidal compositions in microparticulate form.

,. · U.S. Patent 4,675,189 describes long-term. ti release formulations containing the LHRN analog. 35 decapeptide naphtarelin and related LHRN analogs and polylactide-co-glycolide polymer. The release pattern is not described.

106926

The long-term release of biological drugs, enzymes and vaccines from microparticles is described by T. Chang, J. Bioeng., Vol. 1, p. 25 32, 1976. Lactic acid polymers / copolymers and 5 lactide / glycolide copolymers and related compositions for use in surgical applications for sustained release and biodegradation are described in U.S. Patents 3991776; 4076798 and 4118470.

European Patent Application 0203031 describes a group of somatostatin octapeptide analogues, for example, compound RC-160 of the formula: * * D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH 2 having the bridge -Cys sections, columns 15 through 16.

The possibility that somastatin is microencapsulated with a polyactide-co-glycolide polymer is mentioned in claim 18, but no guidance on how to achieve sustained therapeutically active serum levels has been given.

US Patent No. 4,011,312 discloses that continued release of an antimicrobial drug, for example, from water-soluble B polymyxin, a low molecular weight (less than 2000) polylactide-co-glycolide binder, and a relatively high glycolide-containing implant form, can be achieved by ... .; are placed in the cow's udders. The drug is released over a short period of time due to the high glycolide content and low molecular weight of the polymer, both of which stimulate rapid biodegradation of the polymer and thus affect the rapid release of the drug. The relatively high drug content • · · '... · also contributes to the rapid release of the drug.

Somastotins and drug release patterns were not described.

35 European Patent No. 5,8481 describes the stimulation of sustained release of a water-soluble peptide from a polylactide polymer implant by reducing the molecular weight of at least 4,106,926 parts of the polarer molecules, adding glycolide units to the polymer molecule, increasing the polymeric implant area. Although somatostatin is mentioned as water-soluble peptides, somatostatin release patterns have not been described and it is not indicated how all of these parameters are combined to achieve, for example, continuous serum levels of somatostatin for at least one week, for example one month.

European Patent No. 92918 discloses that sustained release of peptides, preferably hydrophilic peptides, over an extended period of time can be achieved when the peptide is incorporated into a conventional hydrophobic polymeric binder, for example, a poly-lactide made more water absorbable by attaching a hydrophilic moiety to its molecule, e.g. , polyvinyl alcohol, dextran, polymethacrylamide. The hydrophilic effect on the amphipathic polymer is administered to all ethylene oxide groups in the case of the polyethylene glycol unit, the free hydroxyl groups in the case of the polyvinyl alcohol or dextran unit, or the amide groups in the case of the polymethacrylamide unit. Due to the presence of a hydrophilic unit in the polymer molecules, the implant obtains hydrogel properties after water sorption. Somatostatin is mentioned as a hydrophilic peptide, but the release profile is not described, and no reference is made to the type of polymer that is preferred for this peptide, or to the molecular weight and how many hydrophilic groups it would have. be.

UK Patent GB 21454222 B describes that <type> of many types of drugs, for example vitamin A. The sustained release of enzymes, antibiotics, and antigens can be achieved over an extended period of time when the drug is incorporated, for example, into a microparticle implant of a polyol polymer such as glucose or mannitol, and having one or more, preferably at least 3, polylactide ester group. The polylactide ester groups si-5 preferably contain, for example, glycolide units.

Peptides such as somatostatin are not mentioned as drugs and serum drug levels are not shown.

The present invention relates to a process for forming a sustained release composition of octreotide or a salt or derivative of the somatostatin analog, for example, a microparticulate composition which provides a satisfactory plasma level of the drug and is encapsulated in a biodegradable, biocompatible polymer. The polymeric binder may be a synthetic or naturally occurring polymer.

The microparticles may be prepared by conventional techniques, for example, an organic phase separation technique in which the polymer is co-precipitated with a drug, followed by curing of the product obtained using phase separation or triple emulsion.

If desired, the sustained release composition may be in implant form.

The present invention encompasses a process for preparing a sustained release composition in which the octre or the salt or derivative thereof is in a biodegradable and biocompatible polymeric carrier, wherein

♦ tl J

A) mixing the drug compound or a solution thereof in methanol or water or a buffer having a pH of 3-8 polylactic acid with methylene chloride;

Da • 35 b) spraying the resulting solution or emulsion of the drug compound in a polymer solution under warm air flow, Ä 106926 6 c) collecting the resulting microparticles or microspheres and washing them with a buffer solution of pH 3.0 to 8.0 or distilled water, and d) drying them in vacuo at 20 ° C to 40 ° C.

The present invention also encompasses a process for forming a sustained release composition comprising octreotide or a salt thereof in a 40/60 to 6% O polyolactide-co-glycol diester, the polyol unit being either a (C 3-6) carbon-10 chain-containing alcohol. having from 3 to 6 hydroxyl groups and a mono- or disaccharide, and the esterified polyols have at least 3 polylactide-co-glycolide chains, wherein a) a mixture of octreotide or a solution thereof in methanol or water or a buffer of pH 3-8 polylactide-co-glycolide ester with a methylene chloride solution; and (b) spraying the resulting octreotide suspension solution or emulsion in a polylactide-co-glycolide solution in a warm air stream;

c) recovering the resulting microparticles or microspheres and washing them with a buffer solution at pH

is 3.0 to 8.0 or distilled water, and: d) dried in vacuo at 20 ° C to 40 ° C.

25 We have found that the new salt of octreotide is a pamoate, which is very stable in such • ·. ·; ·. compositions. Methods for the preparation of octreotide dipoamate are allowed to react with octreotide with embonic acid (or its reactive derivative).

30 The depot composition as defined above is administered to a subject in need of extra-gastrointestinal care, particularly in the treatment of hyperacidity or breast cancer.

The drug used in the process of the invention is preferably water-soluble, for example a peptide.

The peptide used in the method and composition of the present invention may be a synthetic analog of somatostatin.

Naturally occurring somatostatin is a tetra-5 decapeptide of the formula:

Ala-Gly-Cys-Lys-Asn-Phe-Phe-Trp

I I

Cys-Ser-Thr-Phe-Thr-Lys 10 This hormone is produced by the hypothalamic gland, as well as other organs, such as the gastrointestinal tract, and acts in conjunction with GRF, see Neuronuclear Growth Hormone Release Nerve Regulator-15 ly. In addition to inhibiting GH release in the pituitary gland, somatostatin is a potent inhibitor of a variety of systems, including those of the central and peripheral nervous, gastric and small intestine, and smooth muscle. It also blocks the release of insulin 20 and glucagon.

The term "somatostatin" includes analogues and derivatives thereof. They are understood to mean straight chain, bridge or cyclic polypeptides in which one or more amino acid units are omitted and / or are ·; 25 substituted by one or more amino radicals and / or wherein one or more reactive groups are replaced by one or more other reactive groups and / or one or more groups are substituted by one or more other isosteric groups. Generally, the term encompasses all those modified derivatives of the biological peptide which have a qualitatively equivalent effect to the unchanged ♦ somatostatin peptide.

The potent somatostatin analogs are thus useful in replacing the effect of native somatostatin in the regulation of physiological functions. Preferred known somatostatins are: 8 106926 * * a) (D) Phe-Cys-Phe- (D) Trp-Lys-Thr-Cys-Thr-ol (generic name octreotide) * * 5 b) (D) Phe-Cys -Tyr- (D) Trp-Lys-Val-Cys-ThrNH2 * * c) (D) Phe-Cys-Tyr- (D) Trp-Lys-Val-Cys-ThrNH2 * * d) (D) Trp-Cys -Phe- (D) Trp-Lys-Thr-Cys-ThrNH 2 10 * * e) (D) Phe-Cys-Phe- (D) Trp-Lys-Thr-Cys-ThrNH 2 * + f) 3- (2- naphthyl) - (D) Ala-Cys-Tyr- (D) Trp-Lys-Val-Cys-ThrNH2 15 * g) (D) Phe-Cys-Tyr- (D) Trp-Lys-Val-Cys-P -Nal-NH2 * * h) 3- (2-naphthyl) -Ala-Cys-Tyr- (D) Trp-Lys-Val-Cys-β-Nal-NH2 20 * * (i) (D) Phe-Cys- P-Nal- (D) Trp-Lys-Val-Cys-Thr-NH 2 wherein each of the compounds a) - i) has a bridge between the amino acids designated as * in the following formula.

Other preferred somatostatins include: · · 4 → 4 · ··· Λ - - - - - - - - _ - - - - - - - Λ • · ·

'• "I I

* «

'**' H-Cys-Phe- (D) Trp-Lys-Thr-Phe-Cys-OH

30 (see Vale et al., Metabolism, 27, Appendix 1, 139 • · «(1978)), ··· # J * * • · ·

Asn-Phe-Phe- (D) Trp-Lys-Thr-Phe-Gab «<.. .. (see European Patent Publication No. 1295 and Application No. 35 No. 78100994.9), * 2" * * ': MeAla-Tyr- (D) ) Trp-Lys-Val-Phe 9 106926 (see Verber et al., Life Sciences, 34, 1371-1378 (1984) and European Patent Application No. 82106205.6 (published as 70021)), also known as cyclo (N-Me-). Ala-Tyr-D-Trp-Lys-Val-Phe), 5 * *

NmePhe-His- (D) Trp-Lys-Val-Ala (see RFNutt et al., Clin. Wochenschr. (1986) 64 (Appendix VII), * 10 H-Cys-His-Phe-Phe- (D)). Trp-Lys-Thr-Phe-Thr-Ser-Cys-OH (see EP-A-200,188), * * X-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-NH 2 and * * 15 X -Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-ol wherein X is a cationic anchor, especially * *

Ac-hArg (Et 2) -Gly-Cys-Phe-D-Trp-Lys-Thr-Cys-NH 2 (see EP 0363589A2), the above amino acids have a bridge * between the indicated amino acids.

,,, 1 Within all the above publications, including the characteristic compounds, the name -: «· 25 is hereby incorporated by reference.

The term derivative also includes corresponding derivatives having a sugar residue. When somatostatin has a sugar residue, it is preferably linked to the N-terminal amino group and / or at least one amino group 30 is present in the peptide side chain; more preferably N-terminal

• I

* ··· * linked to an amino group. Such compounds and their preparation are described, for example, in WO 88/02756.

♦

The term octreotide derivatives encompasses compounds in which a portion of 35 * * -? - D-Phe-Cys-Phe-DTrp-Lys-Thr-Cys-has a bridge between Cys residues.

10 106926

Particularly preferred derivatives are Na- [α-Glu-cosyl- (1-4-deoxy-fructosyl] -DPhe-Cys-Phe-DTrp-Lys-Thr-Cys-Thr-ol and Na - [β-deoxy-fructosyl] -DPhe-Cys -Phe-DTrp-Lys-Thr-Cys-Thr-ol having a bridge between the -Cys moieties, preferably in the acetate salt form, described in Examples 2 and 1, respectively, in the above application.

Somatostatin can be, for example, in the form of free, salt or complexes thereof. The acid-10 addition salts may be formed with, for example, organic, polymeric and inorganic acids. The acid addition salts include, for example, hydrochlorides and acetates. The complexes are formed from somatosatins, for example, by the addition of inorganic substances, for example, inorganic salts or hydroxides, such as the Ca and Zn salts, and / or by the addition of polymeric organic substances.

For such compositions, particularly in microparticles, the preferred salt is the acetate salt 20 resulting in reduced drug initial discharge. Paomate salt useful especially in implants. The pamoate can be obtained by conventional means. by reaction with, for example, the free base form of octreotide. The reaction may be carried out in a polar solvent, for example at room temperature.

• ·

Somatostatin has been shown to be used in the treatment of conditions requiring long-term use of the drug, such as diseases that involve or are associated with excessive GH • · · isolation, for example, treatment of goiter, gastric ulcer and small intestine. treating diseases such as peptic ulcer; intestinal, skin, and pancreatic stents; irritable bowel syndrome; dumping "sudden clearing" - • · 35 syndrome; watery diarrhea syndrome; haimatuleh-acute meningitis and gastrointestinal umpieristyskasvainten [for example VIPomas, GRFomien, glucagonomas, insulin-4 106926 linoomien, gastronooraien as well as the stomach and the small intestine drain; treatment and prevention of breast cancer and diabetes-related complications.

The polymeric carrier may be made from biodegradable and biocompatible polymers such as linear polyesters, branched polyesters having linear chains radially from the polyol moiety, for example glucose; other esters include esters of polyactic acid, polyglycolic acid, polyhydroxybutyrate, polycaprolactone, polyalkylene oxalate, Krebs cycle acids, for example citric acid, polyalkylene glycol esters and the like, and copolymers.

Preferred polymers of the present invention are linear polyesters and branched-chain polyesters. Linear polyesters may be prepared from alpha-hydroxycarboxylic acid, for example lactic and glycolic acid, by condensation of lactone dimers, see, for example, U.S. Patent No. 3773919.

Linear polylactide co-glycolides, preferably used in accordance with the invention, have a molecular weight of 25,000-100.00 and a polydispersity of M 1 / Mn pre. : indicates 1,2 - 2.

I I I

Preferably, the branched polyesters may be prepared using polyhydroxy compounds, for example, polyol such as glucose or mannitol as initiator. These polyol esters are known and are described in UK Patent GB 2145422B. The polyol has a molecular weight of up to 20,000 and contains at least 3 hydroxy groups such that at least 1, preferably at a price of 2, for example on average 3 polyol · · · hydroxy groups are in the form of ester groups, which contain polylactide or co-polylactide chains. Typically, 0.2% glucose is used to initiate the polymerization (4,35. The branched polyesters have a star-shaped structure. The preferred polyester chains used in the linear and star-shaped polyester compounds are those of alpha-carboxylic acid moieties. copolymers of lactic and glycolic acid, or lactone dimers The molar ratio of lactide to glycolide is from about 75:25 to about 25:75, for example 60:40 to 40:60, and most preferably 55:45 to 25:75, for example 60:40 - 40:60 and most preferably 55:45 - 45:55, for example 55:45 - 50:50 Star polymers can be prepared by reacting the polyol with the lactide, and preferably also the glycolide at high temperature in the presence of a catalyst, which enables a 10 ring opening polymer foundation. We have found that the advantage of the stellar polymer type in the compositions of the present invention is that it can have a relatively high molecular weight to provide a physical stabilizer. for example, known hardness to implants and microparticles, thereby avoiding their adherence to each other, although relatively short polylactide chains are present, resulting in a controlled biodegradation rate of the polymer ranging from several weeks to one or two months and consequently prolonged release of the peptide. prepared de-potent compositions suitable for, for example, one month release.

The star polymers preferably have a parent molecular weight M 'of between about 10,000 and 200,000, more preferably <tt <; 25,000-100,000, especially 35,000-60,000, and the degree of dispersion of poly-? · ... is, for example, 1.7-3.0, e.g. 2.0 - ♦ * 2.5. The intrinsic viscosities of a star polymer having a M w of 35,000 and a M t of t * V * 60,000 are 0.36 and 30 0.51 dl / g in chloroform, respectively. The star polymer, which has a llf ί. ,, ί 52,000, has a viscosity of 0.475 dl / g in chloroform.

** 'i The terms microsphere, microcapsule and microparous'. the sticks are interchangeable with the invention. and indicate the encapsulation of the peptide with the polymer, * * t -,, 35 35 preferably such that the peptide is uniformly distributed in the polymer, which is thus a peptide binder. term microsphere or more generally a microparticle.

Using the phase separation technique of the present invention, the compositions of this invention may be prepared, for example, by dissolving the polymeric carrier in a non-peptide solvent and then adding and dispersing the peptide solution in the polymer-solvent composition. Subsequently, a phase inducer, for example, silicon-10 machine fluid, which induces encapsulation of the peptide with the polymer is added.

The drug release effect can be greatly reduced by insituing the ultrafine drug particles by adding the drug solution to the po-15 polymer solution prior to phase separation. According to the previous method, dry particles were added directly to the polymer solution.

The therapeutic duration of peptide release can be increased by curing / washing the microparticles with a buffer / heptane emulsion. According to the known method, after the curing step, there is no washing or a separate aqueous washing step.

The oil / water type (= δ / v) emulsion can be used to wash and cure microspheres and to remove: 25 non-encapsulated peptide. Washing facilitates removal of non-encapsulated peptide by micropalling. from the surface of the balls. Removal of excess peptide from the microvilli reduces parasitic drug delivery, which is characteristic of many conventional encapsulation compositions. Thus, the present microsphere compositions have a smoother drug delivery over time. The emulsion also facilitates removal of residual polymer solvent *** and silicone fluid. The emulsion may be added to the polymer-peptide mixture or the mixture may be added to the 35 emulsion. It is preferred that the polymer-peptide mixture be added to the emulsion. The o / w emulsion can be prepared using an emulsifier such as sorbitan mono-10,106,926 oleate (Span 80 ICI Corp.) and the like to form a stable emulsion. The emulsion may be buffered with a buffer that is not detrimental to the peptide or polymeric binder. The pH of the buffer may be 2 to 8, preferably 4. The buffer may be prepared from an acidic buffer such as phosphate or acetate buffer or the like. Water alone can act as a buffer. Heptane, hexane and the like can be used as the organic phase of the buffer. The emulsion may contain dispersants such as silicone oil.

A preferred emulsion may comprise heptane, pH 4 phosphate buffer, silicone oil and sorbitan monooleate. When the initial drug release is desired, a single curing step without solvent can replace the emulsion curing. Heptane, hexane and the like can be used as a solvent.

Other options for curing the microcapsules can be used for the o / w emulsion, such as: solvent 20 and emulsifier for curing the microcapsules without washing; and a solvent and an emulsifier for curing, followed by separate washing.

The O / V emulsion can be used without a dispersant. However, the dispersion agent prevents the formation of a dry microcapsule particle due to static electricity. • accumulate and reduce the residual solubility. the number of the receiver.

... Examples of solvent solvents for the polymeric binder are methylene chloride, chloroform, benzene, ethyl acetate, and the like. Preferably, the peptide is dissolved in an alcoholic solvent, for example methanol, which is miscible with the polymeric solvent.

'*' ** Phase-inducing agents (coacervation agents) are solvents that mix with a polymer-drug mixture and cause the formation of microcapsule embryos before curing; silicone oils are preferred phase inducers.

106926 O / V emulsion can be prepared in conventional manner using heptane, hexane and the like in the organic phase.

The microparticles may also be prepared by a well known spray drying process. According to this method, somatostatin or a solution of the peptide in an organic solvent (e.g. methanol), water or e.g. a pH 3-8 buffer and a solution of the polymer in an organic solvent (e.g. 10 methylene chloride) not mixed with the above are mixed thoroughly.

The resulting solution, suspension or emulsion is sprayed in a stream of air, preferably warm air. The resulting microparticles are recovered, for example, with 15 cyclones and washed, if desired, for example at pH 3.0 to 8.0, preferably pH 4, in buffer or distilled water and dried in vacuo at, for example, 20 to 40 ° C. Washing can be performed if the particles exhibit drug release in vivo and the drug release rate is undesirable. An acetate buffer may be used as the buffer.

Accordingly, microparticles with an improved somatostatin release profile in vivo can be provided.

; The sustained release composition of somastatin can be prepared by mixing somatostatin. or a solution of somatostatin in methanol, water, or buffer pH 3-8, and a solution of polylactide-co-glycolide in methylene chloride and by killing *. · 30 formed solution, emulsion or suspension of somatostatin in warm air, Take the microspheres and wash them at pH 3-8. · ”* · In buffer solution or distilled water and vacuum drying at 20 - 40 ° C. Compared to the micro-«* '· particles produced by 35 phase separation techniques, they do not contain silicone oil, not even 4 I 4 4« I · 1K 106926, since silicone oil is not used in spray-drying technology.

The compositions of the invention may also be prepared using the triple emulsion method. According to a topical technique, a peptide, e.g. octreotide, is dissolved in a suitable solvent, e.g. water, and strongly emulsified in a solvent (e.g., methylene-10 chloride) of a polymer, e.g., 50/50 poly (D, L-lactide-co-glycolide) glucose, which is not a solvent for the peptide. Examples of the solvent for the polymeric binder include methylene chloride, chloroform, benzene, ethyl acetate and the like. The resulting water / oil emulsion (v / o) is further emulsified in an excess of water containing an emulsifier, e.g. an anionic or nonionic surfactant or lecithin or a protective colloid, e.g., gelatin, dextrin, carboxymethylcellulose, polyvinylpyrrolidone, nyl alcohol to form a continuous emulsion of 3 to 20 mois (v / v / v). The microparticles are formed by spontaneous precipitation of the polymer and are cured by evaporation of the organic solvent. Gelatin can prevent the accumulation of microspheres. Micro-; after sedimentation of the particles, the supernatant liquid is decanted and the microparticles are washed with water and then with acetate buffer. The microparticles are then filtered and dried.

The peptide may also be directly dispersed in the polymer solution followed by mixing the resulting suspension with an aqueous gelatin-containing phase.

The triple emulsion process is known from U.S. Patent No. • · ·: ... · 4652441. According to this patent, in the first step, the drug solution (1) in a solvent, for example somatostatin in water (column 2, lines 31-32), <4 iit; 35 is thoroughly mixed with a solution of polylactide-co-glycolide. excess (2) in another solvent, for example methylene chloride, in which the former is not soluble to give fine drug-containing droplets (1) in solution (2) water / oil (v / o) emulsion (3). The solution (1) is further dissolved in a so-called drug retaining agent (column 5 l, row 31), for example gelatin, albumin, pectin or agar. In the second step, the viscosity of the inner phase (1) is increased by appropriate means such as heating, cooling, pH change, addition of metal ions or cross-linking with, for example, 10 gelatin aldehydes. In the third step, the excess water is thoroughly mixed with the v / o emulsion (3) (column 7, lines 52-54) to form a v / o / v triple layer emulsion. An excess of water may, if desired, be present in an emulsifier (Sara-15 Wed 7, line 56) such as an anionic or nonionic surfactant or, for example, polyvinylpyrrolidone, polyvinyl alcohol or gelatin. In the fourth step, the w / o / w emulsion is treated with "water drying" (line 52). By this is meant that the organic solvent is desorbed from the oil layer to obtain microparticles. Desorption is carried out in a manner known per se (column 8, rows 3-5), for example by lowering the pressure with stirring (column 8, rows 3-5) or, for example, blowing nitrogen gas through an oil layer (e.g. methylene chloride) (rib 19). ). The microparticles formed are recovered • ♦. by centrifugation or filtration (lines 26-27) and the non-polymeric constituents are removed by washing with water (line 29). If desired, the microparticles of V '30 are heated under reduced pressure to provide improved water and solvent removal (e.g., methylene chloride microparticle wall) (lines 30-32). While the above described 4 · '. The method is satisfactory for the compositions of the invention. However, for the preparation of the microparticles, the so-called drug retaining substance, e.g., gelatin, albumin, pectin or agar, is contained in the so-called drug retaining substance.

We have found that when the drug retaining agent is not added (= to solution 1) and the viscosity of the inner phase is increased and an emulsifying agent or protective colloid such as gelatin is added to the three layer v / v / v emulsion with excess water, microparticles, which do not contain drug retaining agent and only 10 low methylene chloride.

Thus, the invention comprises a process for the preparation of microparticles by vigorously mixing: a) a solution of a drug substance, particularly octreotide, in an aqueous medium, preferably water or buffer, preferably in a weight ratio of 0.8 to 4.0 g / l to 120 ml, in particular 2.5 / 10 and pH 3-8 in buffer, especially acetate buffer; and b) a solution of a polymer, preferably polylactide-co-glycolide, as described above in an organic solvent, for example methylene chloride, which is not mixed with the aqueous medium preferably by weight / volume. in a ratio of 40 g / 90 to 400 ml, especially 40/100, preferably with a weight / weight ratio of drug / polymer of 1/10 to 50, especially 1/16 and a volume of aqueous medium and organic solvent. the volume / volume ratio is l / l, 5 to 30, especially 1/10, • ·. mix v / o emulsion vigorously in [a) (b)] together with * * <* ♦ * * c) an excess of an aqueous medium, preferably * · · · · · 30% water or buffer (preferably pH 3 - 8), for example an acetate or phosphate buffer comprising: an emulsifier or a protective colloid, in particular *** *** gelatin, preferably in a concentration of 0.01 to 15.0%, * * especially in a concentration of 0.1 to 3% %, specifically 0.5 L *, 35% by weight, preferably with a volume / volume ratio of I 4 1 I «at a mixing ratio ab) / c) 1/10 to 100, in particular: · 1/40,« «· ·« · 19 106926 without adding a drug retaining agent to the water / oil emulsion or without using an intermediate to increase the viscosity, curing the microparticle embryos in the formed w / o / w emulsion by desorption, preferably evaporation of the organic solvent, preferably granulated elit.

The present invention also encompasses a variant wherein the drug is directly dispersed in a polymer solution, followed by mixing the resulting dispersion with an aqueous phase containing gelatin. The microparticles produced by these methods, as well as the microparticles produced by the spray drying method, do not contain silicone oil. Compared to the microparticles produced by the known triple emulsion methods, they do not contain a protective colloid.

The sustained release compositions may also be prepared by other methods known per se, for example, if the peptide is sufficiently stable to make the implant, by heating the microparticles containing the peptide, for example somatostatin in polylactide-co-glycolide, particularly as described above; their mixture which <I i, ·. ; 25 is obtained by mixing the peptide and the polymer at a temperature of, for example, 70-100 ° C and extrusion. and cooling to a compact mass, after which the extrudate is cut and optionally washed and dried.

Compositions suitably formed by the process of the invention are prepared under aseptic conditions.

***: By the process of the invention, The compositions may be used in sustained release form, for example, as injectable microspheres or as implants.

2 <. - »20 106926

They may be administered by conventional means, for example, by subcutaneous or intramuscular injection, for example, for symptoms known to affect the drug.

Sustained-release compositions containing octreotide may be administered for indications of octreotide and its derivatives, for example, as described in GB 2199829 A, pp. 89-96, as well as for giant apex and breast cancer.

The microparticles of the present invention have a size range of 1 to 250 microns, preferably 10 to 200 microns, in particular 10 to 130 microns, for example 10 to 90 microns. Implants may have a volume of, for example, 1 to 10 mm 3. The amount of drug or pep-15 tide in the composition will depend on the desired daily release dose and thus the rate of biodegradation of the encapsulating polymer. The exact amount of the peptide can be determined by bioavailability tests. The compositions may contain at least 0.2, preferably 0.5 to 20, more preferably 2.0 to 10, especially 3.0 to 6% by weight of the peptide relative to the polymer binder.

The release time of the peptide from the microparticle may be from one to two weeks to about 2 months.

! "25 A useful sustained release composition comprises somatostatin, e.g., octreotide, in a biodegradable and biocompatible polymeric vehicle, administered subcutaneously to the rat in a dose of 10 · · · * mg of somatostatin to the body weight of an animal. per person appears to have a concentration of somatostatin in plasma of at least 0.3 ng / ml and preferably less than 20 ng / ml for a period of 30 or suitably 60 days.

Alternatively, the sustained release I <r • _ composition comprises somatostatin, e.g. «1 1 21 106926 shows somatbstatin at a concentration of at least 0.3 ng / ml for a period of 50 days and conveniently at a concentration of at most 20 ng / ml.

Other advantageous properties of the resulting somatostatin, for example depot compositions containing octreotide, are, depending on the manufacturing method used:

Phase Separation Technique: Rabbit 5 mg somatostatin / kg intramuscularly 10 retardation (0-42 days) 76% mean plasma level <CP ideal (0-42 days) 4 ng / ml AUC (0-42 days) 170 ng / ml x days

Spray drying technique: 15 rats 10 mg somatostatin / kg subcutaneous retardation (0-42 days)> 75% mean plasma level (CP ideal) (0-42 days) 4-6 ng / ml AUC (0-42 days) 170-210 ng / ml x 20 days rabbit 5 mg somatostatin / kg intramuscular retardation (0-43 days)> 75% mean plasma concentration (Cp ideal) (0-43 days) 4-6 ng / ml 25 AUC (0-42 days) 200 - 240 ng / ml x. days «·« «·] Triple emulsion technique: • ♦« «« * * rat 10 mg somatostatin / kg subcutaneously «« <*. *: deceleration (0-42 days)> 75% • «♦ 30 mean plasma levels (Cp, ideal ) (° - 42 days) 4 - 6.5 ng / ml: ***; AUC (0-42 days) 170 - 230 ng / ml x · «· · '* days rabbit 5 mg somatostatin / kg intramuscular 35 retardation (0-42/43 days)> 75% mean plasma <: · (Cpideal) ( 0 - 42/43 days) 3.5 - 6.5 ng / ml 22 106926 AUC (0 - 42/43 days) 160 - 270 ng / ml x days

The compositions of somatostatin, preferably octreotide and analogues thereof, have the following characteristics: 1. a retardation of at least 70%, preferably at least 74%, for example at least 75, 80, 88 or at least 89% over a period of 0-42/43 days; or, 2. an average plasma level (Cpideal) of 2.5 to 6.5, preferably 4-6.5 ng / ml over a 0-42 day period in rats given 10 mg somatostatin subcutaneously and / or an average plasma level of 3.5 - 6.5, for example 4 - 6.5 ng / ml in rabbits over a period of 0 to 42/43 days when 5 mg of somatostatin is administered intramuscularly and / or 3. The AUC over a 0-42 day period is at least 160, preferably 170 to 230 ng / ml x days in rats administered 10 mg somatostatin subcutaneously and / or AUC of at least 160, preferably 180-275, for example 20,200-2755 ng / ml x days in rabbits over a period of 0-42/43 days when 5 mg somatostatin administered intramuscularly.

For the quantitative determination of the sustained release compositions described above, we have used the area deviation (AD) method, which are. published by F. Nimmerfall and J. Rosenthaler; Intern.

[J. Pharmaceut. 2: 1-6 (1986). Briefly, the AD method * 'calculates the area deviations of the experimental plasma profile from the ideal V * profile, which is a constant average (♦ · «♦ 30 plasma level (= Cp lV) gal) by changing the area below the experimental plasma level / time curve (AUC). 'j rectangle. The% ·% deviation (relative to the AUC) from the percentage deviation is calculated as follows: 35 By this method, the entire measured plasma profile over a preselected time can be determined by a single numerical index.

23 106926

The plasma level profile of the octapeptide analogue of somatostatin of formula * * D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 in rat is described in Scheme 4 in Proc. Natl. Acad. Sci. 85: 5699-5692 (1988).

However, a direct comparison of the plasma levels of the above-described invention with the aforementioned rats cannot be made, since the plasma profile described was based on another route of administration (intramuscular injection) and more importantly, microcapsule concentration (2-6%) and dosing (25-50 mg microcaps). 30 days, albeit at least 45 15 days assays) were not accurately reported. In addition, the poly (D1-lactide-co-glycolide) type used was not accurately described.

The information value 6n of the publication is thus too low to be a prior publication affecting the invention.

The following examples illustrate the invention.

The polymers have a mean molecular weight, as determined by GLPC using polystyrene;

Example 1 One gram of poly (D, L-lactide-co-glycolide) (50/50 µM molar = 45,000; degree of polydispersion ca. 1.7) was dissolved in 15 mL of methylene chloride with magnetic stirring. Followed by the addition of 75 mg Octreotide acetate dissolved in 0.5 ml methanol. To the polymer-peptide mixture was added 15 ml of silicone oil (Trademark • · · <”* <Dow 360 Medical Fluid 1000 es) (silicone fluid). The resulting mixture was added to a mixed emulsion of 400 with 35 ml of n-heptane, 100 ml of pH 4 phosphate buffer, 40 ml of 1 'Dow 360 Medical Fluid at 350 µl and 2 ml of Span 80 (emulsifier). Stirring was continued for at least 10 minutes

M I I

24 106926 minutes. The resulting microparticles were collected by vacuum filtration and dried overnight in a vacuum oven. The yield was about 90% microparticles in the size range of 10 to 40 microns.

The microparticles were suspended in the excipient and administered intramuscularly (IM) at a dose of 4 mg Octreotide to white New Zealand rabbits. Periodic blood samples showed plasma levels of 0.5 to 1.0 ng / ml for 30 days as measured by radioimmuno-10 log analysis (RIA).

Example 2

One gram of poly (D, L-lactide-co-glycolide) glucose (55/45 molar prepared according to GB 2145422 B; M '= 45,000; degree of polydispersion ca. 1.7; prepared from 0.2% glucose) was dissolved in 25 ml. ethyl acetate under magnetic stirring, followed by the addition of 75 mg Octreotide acetate dissolved in 3 ml methanol. To the polymer-peptide mixture was added 25 ml of silicone oil (trademark Dow 360 Medical Fluid 1000 20 es). The resulting mixture was added to the emulsion described in Examples 1. Stirring was continued for at least 10 minutes. The resulting microparticles were collected by vacuum filtration and dried overnight in a vacuum oven. The yield was greater than 80% of microparticles in the size-25 range of 10 to 40 microns.

Microparticles were suspended in excipient * and administered intramuscularly (IM) at a dose of 4 mg

• • »M

* * Octreotide for white New Zealand rabbits.

; Periodic blood samples showed plasma levels of ≤ <* 30 0.5-2 ng / ml for 21 days as measured by RIA.

Example 3

Solution containing 1.5 g Octreotide acetate • · ·. ***. In 20 ml of methanol was added with stirring to a solution of 18.5 g of poly (D, L-lactide-co-glycolide) glucose (50/50 molar, M M = 45,000) in 500 ml of methylene chloride . The phases were separated by adding 500 ml Dow 360 Medical Fluid (1000 es) and 800 ml Dow 360 Med Fluid (350 es) to the peptide-polymer suspension. The resulting mixture was added to a mixed emulsion of 1800 mL of n-heptane, 2000 mL of sterile water and 40 mL of Span 80. Stirring was continued for 10 minutes and the resulting microparticles were recovered by filtration,

Half of the product was dried overnight in a vacuum oven at 37 ° C. The residual methylene chloride level was 1.2%.

The other half of the product was washed by mixing 10 1000 ml ethanol with 1 ml Span 80. After stirring for one hour, the ethanol was decanted and the microparticles were mixed with 1000 ml of n-heptane containing 1 ml of Span 80. After stirring for an hour, the microparticles were collected by vacuum filtration and dried overnight at 37 ° C. The microparticles so washed had a residual methylene chloride level reduced from 1.2% to 0.12.

The combined product yield was 18.2 g (91%) microparticles containing 5.6% Octreotider, 20 average diameter 24 microns, residual heptane 1.5%.

The microparticles were suspended in the excipient and administered intramuscularly in a dose of 5 mg Octreotide to white rabbits. Periodic blood samples 25 showed plasma levels of 0.3 to 7.7 ng / ml for 49 days. as measured by RIA.

Example 4 * 1 One gram of poly (D, L-lactide-co-glycolide) glucose i * '

V * (50/50 molar prepared according to GB 2145422 B)

i · ·!, · '· 3 0; M "= 46,000; polydispersity about 1.7; prepared from 0.2% glucose) was dissolved in 10 ml of methylene-***: chloride with magnetic stirring followed by addition of 75 mg of Octreotide dissolved in 0.133 ml of methanol. Mixture i was vigorously stirred, for example, with Ultra-Turax for 20 minutes at 20,000 rpm to give a suspension of very small Octreotide crystals in a polymeric solution.

26 106926

The suspension was sprayed with a high speed turbine (Niro Atomizer) and the small droplets were dried in a warm air stream to give microparticles. The microparticles were collected by cyclone and dried overnight at room temperature in a vacuum oven.

The microparticles were washed with 1/15 molar pH 4 acetate buffer for 5 minutes and dried again at room temperature in a vacuum oven. The microparticles were sieved (0.125 mm sieve size) after 72 hours to obtain the final product. The microparticles were suspended in the excipient and administered intramuscularly (IM) at a dose of 5 mg octreotide to white rabbits (Chinchilla mixed fetuses) and subcutaneously (s.c.) at a dose of 10 mg / kg to male rats. Periodic blood samples showed plasma levels of 0.3 to 10.0 ng / ml (5 mg dose) in rabbits and 0.5 to 7.0 ng / ml in rats for 42 days as measured by RIA.

Example 5

The microparticles were prepared by spray drying as described in Example 4, except that Octreotide was directly suspended in the polymer solution without using methanol.

The microparticles were suspended in the excipient and administered subcutaneously at a dose of 10 mg / kg Octreotide to 25 male rats. Periodic blood samples showed plasma levels of 0.5 to 10.0 ng / ml in rats for 42 days. tucked away on RIA.

EXAMPLE 6 One gram of poly (D, L-lactide-co-glycolide) glucose.

V * 30 (50/50 molar prepared according to GB 2145422 B)

«In accordance with; M "= 46,000; polydispersity about 1.7; val (***: 0.2% glucose) dissolved in 2.5 ml methylene chloride, followed by addition of 75 mg Octreotide dissolved in 0.125 ml deionized water. For example, the mixture was agitated vigorously with Ultra-Turax for 20 minutes at 20,000 rpm (inner v / v; · phase).

27 106926

One g of Gelatine A was dissolved in 200 ml of deionized water at 50 ° C and the solution was cooled to 20 ° C (outer v phase). The w / o and v phases were vigorously mixed. In this way, the inner v / o phase separated into small droplets which were homogeneously dispersed in the outer v phase. The resulting triple emulsion was stirred slowly for one hour. In this way, the methylene chloride evaporated and the microcapsules hardened from the droplets of the inner phase. After settling of the microparticles with sedimentation, the supernatant was aspirated off and the microparticles were recovered by vacuum filtration and rinsed with water to remove gelatin. Drying, screening, washing and second drying of the microparticles were performed as described in Example 4. The microparticles were suspended in the excipient and administered intramuscularly (IM) at a dose of 5 mg octreotide to white rabbits (Chinchilla mixed fetuses) and subcutaneously (s.c.) at a dose of 10 mg / kg in male rats. Periodic blood samples showed plasma levels of 0.3 to 15.0 ng / ml (5 mg an-20 nos) in rabbits and 0.5 to 8.0 ng / ml in rats for 42 days as measured by RIA.

Example 7

The microparticles were prepared by a triple emulsion technique in the same manner as described in Example 6, with three modifications: * · '1 1. A pH 4.0 acetate buffer of 0.25 ml was used instead of water * 0.125 ml to prepare the inner w / o phase.

After the second microparticles were recovered, rinsing was performed with 1/45 molar acetate buffer «· V * pH 4.0 instead of water.

3. additional washing of microparticles was abandoned.

Example 8 · *** The microparticles were prepared by the triple emulsion technique in a similar manner to that described in Example 7, except that the inner v / o phase was prepared using water containing 0.7% (w / v); instead of acetate buffer.

<· 28 106926

Example 9

The microparticles were prepared in a similar manner to that described in Example 6, except that the drug was directly dispersed in the polymer solution, whereupon the resulting dispersion was mixed with the gelatin-containing aqueous phase.

Example 10

Oktreotidipamoaatti

Octreotide free base 10.19 g (10 mM) and 10 3.88 embononic acid (10 mM) were dissolved in 1 liter of water / dioxane (1: 1). The reaction mixture was filtered and lyophilized to give [0] 20 D = + 7.5 ° (C = 0.35, in DMF) as octreotide dipamate hydrate as a yellow powder. Factor = 1.4, where factor = weight of lyophilisate / octreotide contained therein.

The pamoate can replace the octreotide acetate present in Examples 1-9 and has excellent stability.

Example 11 A solution of 1 g of poly (D, L-lactide-co-glycolide) (50/50 molar, M „= 36,100) in 20 ml of methylene chloride was added to a solution of 100 mg of calcitonin in 1.5 ml methanol. The phases were separated by addition of 20 ml of silicone fluid (Dow 360

i 4 I

, ·,; 25 Medical Fluid 1000 es). The resulting mixture was added to the stirred

1 mL emulsion containing 400 mL n-heptane, 100 mL pH

• ·. 4 phosphate buffers, 40 mL of silicone fluid (Dow 360 Me- (* dical Fluid 1000 es)) and 4 mL of Span 80. After mixing the 10 min · · · V 'microparticles, the microparticles were collected by vacuum filtration and dried over overnight in a vacuum oven at 37. The yield was 1.1 g microspheres containing 5.9% calcitonin.

»Tt · * '*; Example 12. A solution of 9.9 g of poly (D, L-lactide-co-glycolide) (50/50 molar, M „= 44,300) in 140 ml of methylene chloride was added 100 mg of lypressin. The dispersion was stirred with a magnet for 1 hour prior to addition of 140 ml of silicone fluid (Dow 360 Medical Fluid 1000 es) and 2.5 ml of Span 80. 2000 ml of heptane were added to the mixture and stirred for 10 minutes. The resulting microparticles were collected by vacuum filtration 5 clubs, washed three times with heptane and dried for 10 minutes under suction. Half of the sample was washed by stirring in water for 10 minutes; one side was not washed. Both samples were dried overnight in a vacuum oven at 30 ° C. The total yield was 10.65 g microcapsules. The analysis of the washed 10 sample was 0.5% lypressin and 0.6% non-water washed.

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Claims (9)

A process for forming a composition which is released over a long period of time which contains octreotide or a site or derivative thereof in a biodegradable and bio-combinable polymer carrier, characterized in that: a) the drug compound or a solution thereof in methanol or water or in a buffer whose pH is 3 to 8 is mixed with a solution of polylactide-co-glycolide in methylene chloride, and b) the suspension or emulsion of the resulting drug compound is sprayed into the polymer solution in a hot air stream; c) the microparticles or microbubbles formed are recovered and washed in a buffer solution whose pH is 3.0 - 8.0, or in distilled water, and d) they are dried in vacuo at a temperature of 20 ° C - 40 ° C. 2. A process according to claim 1, characterized in that the polymeric carrier is poly (DL-lactide-co-glycolide) glucose. 3. A method according to claim 1 or 2, characterized in that the surface of the microparticles is substantially free from drug compound. 25 4. A process according to any one of claims 1 · ··· - 3, characterized in that the content of octre time is 2.0 - 10% by weight. • · 1 Process according to any of claims 1 to 1, characterized in that the diameter of the microparticles is 1 - 250 microns. 6. A process for forming a composition which is released over a long period of time, which composition contains the octreotide or its salt in polyols 40/60 - 60/40 polyactide co. glycol diester, wherein the polyol unit ____; 35 is an alcohol (C3.6) carbon chain containing 3-6 hydroxyl groups and a mono- or di-saccharide, and in the esterified polyol there are at least 3 polylactide-co-glycol chains, characterized therein. that a) the octreotide or a solution thereof in methanol or water or in a buffer whose pH is 3-5 is mixed with a solution of polylactide-co-glycol ester in methylene chloride, and b) spray the resulting suspension solution or emulsion of the octotride. in the polymer solution in a hot air stream; c) the microparticles or microspheres formed are recovered and washed in a buffer solution whose pH is 3.0 - 8.0, or in distilled water, and d) they are dried in vacuum at a temperature of 20 ° C - 40 ° C. Process according to claim 6, characterized in that the surface of the microparticles is substantially free from drug compound. Method according to claim 6 or 7, characterized in that the octreotide content is 2.0-10% by weight. Method according to any of Claims 6), characterized in that the diameter of the microparticles is 1 - 250 microns. <| r «« ·. 4 · • 4 ♦ • · • · • ♦ · • · «• ·« ··· 4 «4 • · ·« 4 «• · • ♦ aa · • · ·« · 4 4 4 1 4 ** 1 » 4 4 • 4 • i 4 4 4 ♦