PT94628B - PROCESS FOR THE PREPARATION OF FORMULATIONS CONTAINING SOLUTIONS IN WATER OF DELAYED LIBERTACAO - Google Patents

Abstract

A sustained release formulation of a peptide drug compound, preferably a somatostatin like octreotide, e.g. as a pamoate salt. The drug compound is present in a polymeric carrier, preferably a polylactide-co-glycolide especially a poly(lactide-co-glycolide)glucose. The formulation is preferably a depot formulation in the form of a monolithic microparticle.

Description

The invention relates to the process for the preparation of delayed release formulations containing a peptide as the active substance preferably an octreotide similar to somatostatin, for example, pamoate.

The active substance is present in monolithic microparticles of a polymer, preferably a polllactide-coglycolide, in particular, poly (lactide-coglycolide) -glucose which give rise to the delayed release »

Basic principles of the invention

The present invention relates to a process for the preparation of formulations of delayed-release active substances (deposits), in particular, water-soluble peptides, for example, somatostatin or somatostatin analogs, such as octreotide, in an agent biocompatible and biodegradable polymeric carrier 'for example a matrix or a coating, for example, in the form of a graft or, preferably' in the form of a microparticle (also known as a microcapsule or microsphere),

The present invention also relates to those formulations which show satisfactory peptide release profiles over a particular period of time.

Through oral or parenteral administration, peptide active substances often have poor bioavailability in the blood, which is due, for example, to their short biological half-life caused by their metabolic instability. In addition, in the oral or nasal administration of the aforementioned active substances, they often present a weak resorption through the mucous membranes. I left, therefore,

difficult to achieve a therapeutically applicable blood level over a long period of time.

parenteral administration of the peptide active substances ₉ as a deposit formulation) has been proposed in a biodegradable polymer, for example in the form of iaeroparticles or grafts, thereby achieving a delayed release after a period of residence in the polymer that protects the peptide against hydrolytic or enammatic influences from biological media *

Although some peptide active substance (deposit) formulations for parenteral administration are known in a polymer in the form of microparticles or grafts, only in very few cases have satisfactory peptide release profiles been achieved in practice. Special measures are needed to achieve a continuous release of the peptide to the therapeutic level of the active substance in the serum, and also to avoid, if desired, excessively high concentrations of substance in the serum, which cause unwanted pharmacological side reactions.

release schedule of the peptide active substance depends on a large number of factors, such as the type of the peptide and, for example, whether it is present in its free form or in another form, for example, in the form of salt, which can influence in its solubility in water. Another important factor is the choice of polymer from the numerous possibilities described in the literature.

Each type of polymer has its characteristic rate of biological degradation. Free carboxyl groups can be formed which contribute to the p'í value in the polymer, thereby exerting an additional influence on the peptide's water solubility and therefore on its release schedule.

Other factors that may influence the release schedule in the delayed release formulation (deposit) are the loading of the active substance in its polymeric carrier, the form of the sus. distribution in the polymer »the particle diameter and, in the case of a graft, additionally its shape.

3® influence is still that of formulation in the body.

To date »no sonatostatin composition in the form of delayed release for even administration. _; iterative, chc-gou to be introduced in the market this is possibly due to the fact that it was not possible to obtain a composition or to present a satisfactory serum level profile.

3itScm; A0 ia αχηλολ

They are known in the art to form volimeric reactions with active subatancies designed to provide a prolonged or delayed release of the active substance.

There is latent American Death HS. 3,773,915? describe controlled-release formulations of the active substance, in which, for example, a water-soluble peptide substance is dispersed in a linear polylactic acid polymer or a bio-degradable and biodegradable polylactic acid polypeptide polymer. However, in that patent, no release models of the active substance are described, nor are there any references to a somatostin. U.S. Patent 4,253,539 describes anti-bacterial formulations in the form of particles.

The American Death Patent MS. 4,675,133 describes formulations of the sustained release of the 1Ί decarptide analogue of nafarelin and the similar XMlf analogs □. · Polylactide-co-glycolide polymers, known as d-33-

describe any model of liberation.

T. Chang, 1. Bioeng., Tome 1, pages 25-32, 1976, describes the prolonged release of biological substances, enzymes and vaccines from microparticles.

In US Patents Nos. 3,991,776;

076 798 and 4 118 470 describe polymers / copolymers of lactic acid and lactide / glycolide copolymers and related compositions, intended for use in surgical applications and for delayed release and biodegradation.

In European Patent ^'r s. 0.203 031 describes a series of somatostatin octapeptide analogs, for example Compound RC-160, which has the formula;

38

D-Phe-Cys-Syc-D-Srp-ljzs-Val-Cys-Trp-NHr, “£, which has a bridge between the parts -Cys- in columns 15-16.

In claim 18 of said patent application, the possibility of microencapsulation of somatostatins with a polylactide-co-glycolide polymer is mentioned, but without giving any instructions on how to achieve a therapeutically active continuous serum level.

U.S. Patent 4,011,312 describes the possibility of a continuous release of an antimierotic active substance, for example, water-soluble polymixime B, from a low molecular weight (lower than polylactic-co-glycolide matrix) to 2000) and with a relatively high content of glycolide, in the form of a graft, by grafting it into the groove of a cow. Due to the high glycolide content and the low molecular weight of the polymer, the active substance is released within a short period of time, as both factors

they stimulate a rapid biodegradation of the polymer and, therefore, a correspondingly rapid release of the active substance. A relatively high loading content of active substance further contributes to a rapid release of the active substance. ^T! Said patent does not disclose somatostatin nor any templates are given for the release of the active substance.

According to the 'European Patent !!?. 53431 the continuous release of a water-soluble peptide can be stimulated from a polylactic polymer graft by reducing the molecular weight of at least a part of the polymer molecules by introducing glycolide units into the polymer molecule , by increasing the polymer character in the whole of the polymer if polylactide-co-glycolide molecules are used; by increasing the charge content of the active substance in the polymer rich matrix and by swelling the graft surface.

Although somatostatins are mentioned in the aforementioned patent as water-soluble peptides, somatostatin release profiles are not described there, nor are indications given about the combination of all the referred parameters to obtain, for example, »a level of somatostatin in the serum that is keep continuous for at least a week, for example, for a month.

European Patent IJô, 32913 describes the possibility of obtaining a continuous release of peptides, preferably of hydrophilic peptides' over an extended period of time, by incorporating the peptide in a usual hydrophobic polymeric matrix, for example in a matrix of a polylactide that has become more accessible to water by introducing a hydrophilic unit into its molecule, for example polyethylene glycol, polyvinyl alcohol 'dextran, or polysetacrylic amide. The hydrophilic contribution to the polymer

«. V _

amphipathic is present was all ethylene oxide groups in the case of a polyethylene glycol unit, for free hydroxyl groups in the case of a polyvinyl alcohol unit or a dextran unit, and for the amide groups in the case of a polymethacrylamide unit. Due to the presence of hydrophilic units.in the polymer molecules, the graft will obtain, through water absorption, hydrogel properties. ^'T re wound patent refers to somatostatin as the hydrophilic peptide, but does not describe the profile nsm release is give indications about the type of polymer preferred for said peptide or on the molecular weight and the number of GRU wells hydrophilic that such a polymer should have.

According to British Patent GB 2 145 422 B, a delayed release of various types of active substances, for example, vitamins, enzymes, antibiotics, antigens, can be achieved over a long period of time, if incorporated the active substance in a graft, for example a microparticle size, prepared from a polyol polymer, for example glucose or mannitol, having one or more polylactide ester groups, preferably at least 3 polylactic ester groups. The polylactide ester groups contain »preferably» for example, glycolide units.

In said patent, peptides are not mentioned, for example, somatostatins, as active substances, nor are the levels of active substance in the serum indicated.

K3SW 0 SA IHVBHÇÍO

The present invention relates to delayed release formulations, for example, with formulations in the form of microparticles, an active substance, in particular an hourly active somatostatin, soluble in water or a somatostatin analog, such as octreotide, which

will provide a satisfactory level of active substance in the plasma, and which are incorporated, for example, in a biocompatible, biodegradable polymer, for example in a polymeric encapsulation matrix. The polymeric matrix can be a natural or synthetic polymer.

The microparticles of the present invention can be prepared by any usual technique, for example, by an organic phase separation technique, by a spray drying technique or by using a triple emulsion technique; if the phase separation or triple emulsion technique is used, the polymer is precipitated together with the active substance and the resulting product is then hardened,

The delayed-release formulations may, if desired, be in the form of a graft,

The applicant has now discovered a particularly useful modification of the phase separation technique, thanks to said technique, microparticles can be prepared from any active substance.

In accordance with the present invention, a process is thus offered for the preparation of a microparticle which comprises an active substance in a biocompatible, biodegradable carrier, a process which proceeds as follows:

(a) the polymeric carrier material is dissolved in an appropriate solvent in which the active substance is insoluble,

b) a solution of the active substance is added in a suitable solvent, for example, an alcohol, which is not a solvent for the polymer in the solution obtained in step a),

c) a phase of the inducing agent is added to the dispersion

ο are obtained in step b), to start the formation of the syroparticle,

d) an oil-in-water emulsion is added to the mixture obtained in step c) in order to harden the microparticle, and

e) the microparticle is recovered.

The inventor has also discovered an especially useful modification of the triple emulsion technique for preparing microparticles from any active substance.

The present invention therefore offers:

A process for preparing microparticles that comprises:

(i) perfectly mix a water-in-oil emulsion formed from an acidic medium and an organic solvent not miscible with water which contains in one phase the active substance and in the other phase has a biocompatible polymer, biodegradable, with an excess of an aqueous medium containing an exuberant substance or a protective colloid in order to form a water-in-oil-watery emulsion, without adding another retention substance to the water-in-oil emulsion or applying it as little any intermediate step to increase viscosity, (ii) desorb the organic solvent from the emulsion, (iii) isolate and dry the resulting microparticles.

The present invention also provides:

a) A delayed-release formulation comprising a peptide as a component of the active substance in a 40/50 to 60/40 polyolefin-co-glycolide ester of a polyol, and that ss chooses the polyol unit from the group of a carbon chain (0 -, - 0 / «) containing alcohol with 3 to β hydroxyl groups and □ a mono-saccharide or a di-saccharide, with the polyol esterified 10 -

at least 3 polylactide-co-glycolide chains.

b) A delayed release formulation comprising a peptide as an active substance compound, I chose

M * of the group of a soaatostatin, calcitonin or lipresin in a polylactide-co-glycolide polymer 40/60 to 50/40 which has linear chains with a molecular weight between 25 »000 and 100,000, uses polydispersity between 1, 2 and 2 at a concentration of 0.2 preferably from 2 to 10% by weight of the peptide as an active substance compound contained in the polymer base.

c) Use a delayed release formulation comprising an octreotide or a salt thereof in a polymeric / biocompatible, biodegradable carrier.

The applicant has discovered that a new octreotide salt, pamoate, has a high stability in said formulations. The present invention therefore offers (I) in octreotide pamoate and (ii) a process for the preparation of. octreotide pamoate, a process that involves reacting octreotide with embonic acid (or with a reactive derivative thereof) 5 «

The present invention further offers.

Us? method for administering a peptide to a patient, which method comprises parenterally administering a delayed release formulation (depot) as defined above, to a patient in need of such treatment, in particular for the treatment of acromegaly or breast cancer.

DSCRIPTION Μ VAHIAOE 1R3PEBI3A

The active substances used in the process of the invention are preferably active substances soluble in water, for example peptides.

The peptides to be used in the processes and formulations of the present invention can be calcitonins, such as salmon ealcitonin, lypresin and somatostatin, which occur in nature, as well as their synthetic analogues, k natural somatostatin is one of the preferred compounds, it is a tetradecapsptide with the following structure:

Ala-Gly-Qys-hys-Asn-PIie-fhe-írp

Oys-Ser-Thr-Phe- ^ hr-Iys

This hormone is produced by the hypothalamus gland and other organs, for example in the gastro-irtestinal (GI) tract, and acts, together with OKF, as a mediator in the neurological regulation of the release of the pipuitary growth hormone. In addition to inhibiting the release of pituitary hormone (GH), somatostatin is a potent inhibitor in a large number of systems, including the central and peripheral neurological systems, in the gastro-intestinal system and in the soft vascular muscles. Mat somatostatin also inhibits the release of insulin and glucagon.

somatostatin ”includes analogs or derivatives thereof. Somatostatin derivatives and analogues are understood to mean straight, bridged or cyclic polypeptides, in which one or more amino acid units have been omitted and / or replaced by one or more amino radicals, and / or er one or more groups Functional groups had been replaced by one or more functional groups and / or one or more groups had been replaced by one or several other isosteric groups. The term generally encompasses all modified derivatives of a biologically active peptide, which exhibit an activity qualitatively similar to that of the unmodified somatostatin peptide.

The agonist analogs of soEiatostatin are therefore useful to replace natural soniatostatin in its regulating activity of physiological functions »The preferred known somatostatins are:

jK 8;

a) (s) Phe-Cys-The- (D) Trp-Iys-Thr-Cys-fhr-ol (generic home Oetreotide)

5K b) (D) W-Oys-lyr- (D) Trp-Lys-Val-Ojrs-VhrHVp a? 85 e) (D) Phe-Cys-2yr- (J>) frp-Lys-Val-Oys-frplHg

3C d) (D) f rp-Oys-Phe- (D) Trp-nys-? Hr-Oys-f hrT ϊΐίρ x * e) (D) Phe-Gys-Phe- (3) Trp-Iys-Thr- Oys-ThrTTHg * *

f) 3 ~ (2- (ITaf til) - (D) Ala-Cys-Tyr- (5)? rp-Xys-Val-Cys-ThrIH ₂ ac 85

g) (3)? he-0ys-2yr- (15 5 Trp-3y s-Val-Cys-β -HaX-IUIg ac ac

h) 3- (2-naphthyl) -Âla-Cys-fyr- (D) Trp-Iys-Val-Gys - ^ - Nal-Nhp

3K

i) (D) Phe-Oys-β-Val-CBjTrp-Iys-Val-Cys-fhr-H2 in which in each of the compounds a) are. í) ₅ there is a bridge between amino acids marked with an asterisk «, as indicated in the following formula»

Other preferred soinatostatins are:

85— ___ * ^? -Cy3 ~? Íie-? He (3}? Rp-Iys-2hr-Mie-Cys ~ 0n (see Vale et al., Jfetãbolism, 27, Supp <l, 139 (1973))>

* *

Asn-Phe-Phe-- (D) Trp-lys-Tlir-Plo-Caba (see European Patent Publication Π ^2. 1295 and Patent Application us. 73 100 994.9).

5K 3S

E 'eAla-? yr- (D) Trp-lys-Val-Phe

See Verber et al., Life Sciences, 34, 1371-133 (1924) and European Patent Application -'2. „2105295 · $ (published under 0 ps, 70021), also known as a cycle (n-Le-Aia-7y5> 3-? Rp-Iys-Vsl-Phe).

as 5K bLePhe-4is- (D) Prp-Iys-Val-Ala (See Pi.T.íTutt et al., Plin.Uochenschr. (1936) 64 (Suppl. ντι) * * '• -0ys-3is -P'is-Phe-P'hô- (D)? ^{rp-Lys-Tlir-The-,?} hr-Ser-0ys-0H (See SP-A-2cc, 183).

«$ <

P-Cjs- ^ ie-E- ^ rp-Iys-Thr- ^ ys-Thr-ZIg c

Z-Íys-TT-te - ^ - Trp-iys - ^^ - ^ s-Vluí-ol en: çue) is a special cationic bond (as

Ac-h 4rg (Etg) -9l2b-Cys-Hie-3-3rp-lvs-'-? Hr ~ Cys-’2Í2 (See-εο C3S3539A2) · er ·. In the aforementioned amino acids, there is a bridge between coarse aniinodeido-s. an asterisk in this description are incorporated, by reference,

β the contents of all the publications mentioned above, çue include the specific compounds · derivative suit ”also includes the corresponding derivatives that contain a sugar radical.

When soatostatins contain a sugar radical, it is preferentially attached to an if-terminal amino group and / or at least to an amino group present in the side peptide chain; most preferably it is attached to an amino-amino group. Such compounds and their preparation are described in CO 88/02755.

derivative of octreotide ”comprises aouole4 which include part

-? k

-D-She-Oys-Bie-BTrp-Iys-Thr-Oys Particularly referenced derivatives are the rJS- ^ Sõ-glu cosil- (l-4 “deo :: ifmctosil7 - 'D2he“ 027a-Phe-3jTz'p ~ I ₍ ys-Thr-0yo- ^n, hr-ol and ns - ^ - dsoxifiJUctosil-DSIie-Cys- ^ iie-BTrp-II -ys-Thr-0ys-7hr-ol; each of these derivatives has a bridge between the parts -Gys- and is present, preferably, in the form of acetate salt, are described in sections 2 and 1, respectively, of the aforementioned patent application.

Somatostatins may exist, for example, in the free form, in the form of salt or in the form of color-plexes thereof. Acid addition salts can be formed, for example, with organic acids, with polymeric acids and with inorganic acids. Acid addition salts include, for example, hydrochloride and acetates. The complexes are formed, for example, from somatostatins with 'addition of inorganic substances, in example, mineral salts or hydroxides, such as Ca and 7n salts and / or with the addition of polymeric organic substances.

The acetate salt is a preferred salt for such formulations, especially for microparticles that contain a reduced initial increase of the active substance. The present invention also offers pamoate salt which is useful, particularly for grafts, and the process for the preparation -nesno.

pamoate can be obtained in the usual way> for example by reacting eiabonic acid (pasotic acid) with octreotide, for example, in the free base form. The reaction can be carried out in a polar solvent, for example, at room temperature.

Soaatostatins are indicated to be used in the treatment of diseases that require the application of the active substance over a long period of time, for example of conditions with an etiology that comprises or is associated with an excessive secretion of growth hormone (CH) , for example, in the treatment of acromegaly; for use in the treatment of gastro-intestinal conditions, for example, o'u treatment in the prophylaxis of peptide ulcers, enterocut-sneas and pancreatic-pancreatic fistulas of the intestinal irritation syndrome, the discharge syndrome ^ diuaping ”, the hydro syndrome -diarrheal, acute pancreatitis and syndocrine-gastro-enteropathic tumors (for example, CTt? -oaas viruses, glúcagonomas, insulinomas, gastrinomas and earcinoid tumors), as well as in the treatment of trace-intestinal hemorrhages, in cancer breast cancer and complications associated with diabetes,

The polymeric agent can be prepared from biocoapable and biodegradable polymers, such as powders. linear ligands, branched polyesters, butts are radical linear chains from a polyol part, for example, glucose, as further esters we can mention the esters of polylactic acid, polyglycolic acid, polyhydroxybutyric acid, polycaprolactone, oxalate

polyalkylene, the polyalkylene glycolic esters of the Zreb cycle, for example the citric acid cycle and the like, as well as the copolymers of said polymers.

The preferred polymers of the present invention are linear polyesters and branched chain polyesters.

Linear polyesters can be prepared from '(-hydroxy-carboxylic acids, for example lactic acid and glycolic acid, through condensation of the lactone dimers, see, for example, the North American patent NS. 3 773 919.

The linear polylactide-o-glycolides used in the process of the present invention, conveniently have a molecular weight comprised between 25,000 and 100,000 and a polydispersity W / L'n comprised, for example, between 1.2 o 2.

The branched polyesters preferably used according to the present invention can be prepared using, as initiator, polyhydric compounds, for example, a polyol, for example, glucose or mannitol. Such esters of a polyol are known and are described in United Kingdom patent P3 2 145 422 B. The polyol contains at least 3 hydroxy groups and has a molecular weight of up to 20,000, provided that by manes 1, preferably at least 2, as a medium term for example 3 of the polyol hydroxy groups are in the form of ester groups, which contain poly-lactide or poly-lactide chains. To initiate polyaerisation, 0.2% glucose is typically used. Branched polyesters have a star-like structure. The polyester chains in the linear polymers and star-shaped polymers used preforeneialffiente according to the present invention, are copolymers of the lactic acid and glycolic acid parts of the lactone dimers. The molar ratios of lactideiglycolide are comprised of 17

acid between 75:25 and 25:75 »for example, between 50:40 and 40:50, and between 55:45 θ 45:55» most preferably »for example, 50:50.

The polymers in the form of stars can be prepared by reacting a polyol with a lithium and, preferably, also with a glycolide at elevated temperature »in the presence of a catalyst capable of enabling a polysizing of the opening cycle.

The applicant has discovered that the type of star-shaped polymer present in the formulations of the present invention can advantageously have u. relatively high molecular weight, which gives the grafts and the raícroparticles a physical stability »for example» a certain hardness, avoiding them or 'sticking together` despite the presence of relatively short polylactide chains, which leads to a controllable rate of polymer biodegradation between a few weeks to one or two months 'and a correspondingly delayed release ^Ί ο peptide' thanks to which the deposit formulation prepared from said polymers is suitable »for example, for a polymers star-shaped have preferably an average rolleular weight (Ç) between approximately 10 »000-and 200» COO »preferably between 25 000 and ICO 000» © speeialments from 35 to 50,000 »and a polydispersibility, for example, 1, 7 to 3.0, in the example of 2.0 to 2.5. The intrinsic viscosities of the star-shaped polymers with an average molecular weight of 35,000 and an average molecular weight of 50> ⁿ 00 are respectively 0.35 and 0.51 dl / 3 sn chloroform. A star polymer with an average molecular weight of 52,000 has a viscosity of 0.475 dl / g in chloroform.

The tiered “microsphere” mierocapsule and mieropartite

la · 'are interchangeable in the present invention and indicate encapsulation of the peptides by the polymer »preferably incorporation by distribution of the peptide into the polymer» thus forming the latter a matrix for the peptide. In the latter case, the "baicrosphere or, more generally, microparticle" are preferably used.

By employing the phase separation technique according to the present invention, the formulations of the present invention can be prepared by dissolving, for example, the polymeric carrier material in a solvent in which the peptide is insoluble, «immediately adding and dispersing a solution of the 'zs peptide. polymer and solvent composition. A phase inductor, for example, a fluid silieone, is added in order to initiate the encapsulation of the powder by the polymer.

The effect of abruptly absent use of the active substance can be reduced in a sequential manner through precipitation in situ, of the ultra fine particles of active substance. If, prior to the separation phase, the active substance solution is added to the polymer solution. Ç-ranas & this method, dry particles are added directly to the polymer solution.

The therapeutic duration of the release of the peptide can be increased by hardening / washing the microparticles with us. << buffer / lioptane emulsion * This method comprises a hardening step followed either by a subsequent washing or by a washing step. separate aqueous wash.

For washing and hardening of the microspheres and for the elimination of the non-encapsulated peptide, an oil-sm-water-type emulsion can be used. Washing helps to eliminate the non-encapsulated peptide from the surface of the microspheres.

Elimination of excess peptide from microspheres li15 -

reduces the effect of increase '. rusco iaieivl, carauteris in a large number of conventional encapsulation formulas. Thanks to the microsphere formulations of the invention, a more uniform release of the active substance ensues over a certain period of time.

Said emulsion also contributes to eliminate □ residual polymeric solvent and fluid silicone, it is recommended to add such emulsion to the peptide-polymer mixture »or else to add this mixture to the emulsion, preferably adding it and the peptide-polymer mixture to the emulsion.

The ρο · β oil / water emulsion can be prepared using an erulsing agent, such as sorbitan mono-oleate (Span 30 ICI Corp.) and the like, to form a stable eaulsion. Tapones * can be added to said emulsion with a non-soy cue buffering agent harmful to the peptide or to the polymeric matrix material »It may be a buffering agent with pH 3 to 3» preferably with a p: 'ds 4. Y & 1 buffer can be prepared from acidic buffering agents, such as phosphate buffer, acetate buffer and the like. Only water can possibly replace the tanning agent.

Co .-. The organic phase of the buffer can be used heptane, hexane and the like »

The emulsion may contain dispersing agents, such as silicone oil.

The preferred use-enulsion may comprise heptane, a phosphate buffer with a powder of 4, silicone oil and sorbiting non-oleate. If an initial release of the substance is desired. active, hardening with a single-stage emulsion can be replaced, without hardening. As a solvent, heptane, hexane and the like can be used.

For the hardening of micro-capsules, other alternatives to the oil / water emulsion can be used, namely:

* · V

A solvent is an emulsifying agent for the hardening of the microcapsules, see washing, and we have dissolved another © an emulsifier for the hardening of the microcapsules »with subsequent washing separately *? The oil / water emulsion can be used without using a dispersing agent However, the dispersing agent prevents the aggregation of dry microcapsule particles due to static electrolyte, and contributes to reducing the level of the residual solvent.

Examples of solvents for the polymeric matrix matter include methylene chloride, chloroform, benaene, ethyl acetate and the like »The peptide is dissolved profferentially in an alcoholic solvent, for example methanol» which be flexible with the polyester solvent.

The phase-inducing agents (curing agents) are dissolved in the active polymer-substance mixture, causing the formation of mierocanns as crystal embryos, before curing, preferred phase inducers are silicone oils.

The oil / water emulsion can be prepared according to the usual conditions, using for orpinica fossa, heptaao »hexane and the like.

The microparticles of the present invention can be prepared in this way, by the spray drying process generally known »According to this method» is somatostatin or a naked peptide solution perfectly mixed? organic solvent, for example methanol »in water or in a buffering agent, · for example with a shovel of 3 to 8, is a solution of the polymer in an organic solvent other than soy niscible with the previous organic solvent» for example methylene chloride.

The suspension or emulsion solutions thus forced are then sprayed on. air jet, preferably hot air. The microparticles generated, eg by a 'cyclone', are reooled and, if desired, washed, for example in a tapa solution, for example with a pd of 3.0 to 0.0 ', preferably a pH of 4.0, or with distilled water and dried under reduced temperature, for example, heat 20 to 40 ° C. It is possible to carry out the step of washing x the shard sx and the particles present a “sudden live” of a sudden increase in the active substance and such a sudden increase in the active substance is considered inappropriate. Ke such a case? i-.ç-ur can be used with acetate buffer.

Therefore, iaieroparticles can be obtained and they present “in vivo” a better release · of somatostatin.

The present invention therefore also relates to the microparticles prepared by said procedure. Also, the invention offers a delayed-release formulation, a formulation, which is prepared by mixing a somatostatin or a solution from one somatostatin in methanol or in water or in a buffering agent with a pi of 3-3 with streets, solution of the polylactide-o-slicolide in methylene chloride and then spraying the occlusion, emulsion or suspension of somatostatin so formed in a solution of polymer under a hot air jet, then re-collect the microspheres and wash them in a buffer solution with a pH of 3.0 & 3.0 or in distilled water and, finally, cook them at a temperature o at 40 ° C under reduced trap, free eoxgarxation with the microparticles prepared according to the phase separation technique, the microparticles prepared as described here are free from oil. does not have ?, gi ^ alner silicone residue, since the spray-drying technique is carried out before the silicone oil.

The formulations of the present invention can therefore be repaired, using a triple-emulsion procedure. According to a typical technique, the peptide is dissolved by ereupl ': the octreotide, in an appropriate solvent, for example in water, and emulsified perfectly in a polymer solution, for example, 53/50 poly (0 , D-lactide-co-glycide) glucose in a solvent in the oral the peptide remains undissolved, by ere-τρίο, methylene chloride.

Ooo.o examples of solvents for the polymer matrix material can be reinforced; methylene chloride, chloroform, benzene, acetate 'and ethyl and the like. The resulting water / oil errors are subsequently emulsified in an excess of water containing an eyrulsant substance, for example, an anionic or nonionic surfactant or lecithin or a protective colloid, for example »gelatin, dextrin, carfeoxyethylene cellulose , polyvinylpyrrolidone »polyvinyl alcohol, which provide a continuous generation to the triple orulsion (water / oil / water). The mieropar '' are forced by spontaneous precipitation of the polymer and dried by evaporation of the organic solvent. Δ rslatina serves to inhibit the agglomeration of the Mero-spheres. After sedimentation, from the syrups, decant it and the supernatant and wash the microparticles »first with water and then con · up; acetate buffer. Pinalmeute microparticles and seeau-ss were filtered.

ga, 2béí; i it is possible to disperse the peptide directly in the polymer solution and then mix the resulting suspension with the water phase rue and then: u gelatin.

• '• the latent' Forte-Mericana? TS. 4,552,441 describes the triple-emulsion process. According to the aforementioned patent, in a first step, a solution of active substance (3) in a solvent is perfectly mixed, for example <somatostatin in water (Column 2, lines 31-32), with? ul er- 23 -

access of a polylactide-co-glycolide solution (2) a second solvent in which the first solvent is insoluble, for example methylene chloride, which provides an emulsion of the water-in-oil type (3) of small droplets containing the active substance (1) in solution (2).

The solution (1) further dissolves a substance called active substance retention substance (Column 1, line 31), for example gelatin, albumin, pectin on top.

second step, does the viscosity of the inner phase (1) increase through appropriate measures, such as heating, cooling? changing the value of p? ‘, adding metal ions or crosslinking, for example gelatin with an aldehyde.

In a third stage, excess water is mixed perfectly with the water-oil emulsion (3), (Column 7, lines 52-54), which leads to a ternary layer emulsion of the water / oil / water type. If desired, an so-called emulsifying agent (Column 7, line 56) may be used in excess of water, chosen, for example, from the group of an anionic or non-ionic surfactant or, for example, uolivinylpyrrolidone, polyvinyl alcohol or gelatin.

In a fourth stage, the water / oil / water emulsion is subjected to an “in-water drying” (line 52); this is to say that if the organic solvent is desorbed into the oil layer, it caused microparticles to be generated.

Desorption is carried out according to methods known per se (Column 8, lines 3-5), eg under decreasing pressure with simultaneous agitation (Column 8, lines 5-7) or, for example, by introducing a jet of ezoto gas through the · oil layer '(eg n-ethylene chloride) (line 10).

The microparticles formed are collected by centrifugation or filtration (lines 26-27) and the components not incorporated in the polymer (line 29) are washed with water. In certain cases, microparticles are heated under reduced pressure to better remove water and solvent (eg methylene chloride) from the surface of the microparticles (lines 30-32).

However, although the aforementioned process is satisfactory for the production of the formulations according to the present invention, the so-called retention substance mentioned above, for example gelatin, albumin, peetin or agar, are still incorporated in the microparticles of the said process.

The applicant has now discovered that satisfactory microparticles can also be obtained by omitting the addition of the retention substance (»in the solution (l)) and also omitting the step carried out in order to increase the viscosity of the inner phase, but maintaining on the other hand , in excess of water in the ternary water / oil / water emulsion, the measure of adding an emulsifying substance or a protective colloid, such as gelatin. Such microparticles are, in addition, free of active substance retaining substance, and contain only a minimal amount of methylene chloride.

The present invention therefore offers »a process for the preparation of microparticles» a process which comprises mixing perfectly

a) A solution of an active substance, preferably a somatostatin, especially octreotide, in an aqueous medium, preferably water or a buffering agent 'preferably in a weight / volume ratio of 0.8 to 4.0 / 1 to 120 ml, especially 2.5 / 10 and in a buffer with a pH of 3-8, especially an acetate buffer, and

h) A polymer solution, preferably

a polylactide-co-glycolide, as mentioned above, in an unmixable organic solvent with the aqueous medium, for example methylene chloride, preferably in a weight / volume ratio of 40 g / 90 to 400 ml, especially 40/100 , preferably in such a way that the ratio between the active substance and the polymer is 1/10 to 50, in particular 1 / l and the volume / volume ratio between the aqueous medium / organic solvent is 1A, 5 at 30, especially 1/10, and the water-oil emulsion of

a) in b), together with

c) an excess of an aqueous medium, preferably water or a buffer, for example an acetate or phosphate buffer, preferably with a pH of 3 ~ S; which contains an emulsifying substance or a protective eoloid, preferably in a concentration of 0.01 to 15.0%, particularly gelatin, especially in a concentration of 0.1 to. 3%, particularly 0.5% by weight, preferably in a volume / volume (mixing speed) ratio of ab) / c from 1/10 to 100, especially from 1/40, without the water-in-oil emulsion any substance that can retain the active substance is added, even if an intermediate step is applied to increase viscosity; the microparticles are hardened into embryo-form in the water-oil-water emulsion, formed by desorption »preferably by evaporation of the organic solvent, preferably methylene chloride, and then the generated microparticles are isolated, optionally washed and dried The invention also provides a variant of the process according to which the active substance is dispersed directly in the polymer solution and the resulting dispersion mixed with the gelatin containing the water phase.

The invention thus provides microparticles produced in accordance with the processes mentioned in

invention. In the same way as microparticles prepared according to the spray drying technique, they do not contain silicone oil.

These microparticles, in comparison with those prepared according to the spray drying technique, are free of protective colloid.

Delayed release formulations can also be produced by other methods known per se, for example,

- if the peptide is sufficiently stable for the production of a graft, the formulations are prepared by heating the peptide-containing mieroparticles, for example a somatostatin in a polylactide-co-glycolide, especially as described above or a mixture thereof, obtained by mixing the peptide with the polymer, at a temperature comprised, for example, between 70 ° and 100 ° C, followed by extrusion and cooling of the compact mixture; then, the extrusion product is cut, optionally washed and dried.

The production of the formulations of the invention is carried out and even under aseptic conditions.

The formulations prepared according to the invention can be used in the form of delayed release (deposit), for example as injectable microspheres or as grafts.

Said formulations can be administered in a conventional manner, for example by subcutaneous or intramuscular injection, for example according to the known indications for the substance contained therein.

Octreotide-containing delayed-release formulations can be administered for all known indications for octreotide or derivatives thereof, for example

pio, as described in Keino Tinido patent. 2 199 829 A, pages 89-95, and also for the treatment of acromegaly and breast cancer.

The mieroparticles of the present invention can have a diameter of approximately 1 to 250 microns, preferably from 10 to 200, in particular from 10 to 130, for example from 10 to 90 microns. Grafts can have a size, for example, of approximately 1 to 10 cubic millimeters. The amount of active substance, that is, the amount of peptide present in the formulation depends on the release of the desired daily dose and, therefore, on the rate of bio-degradation of the encapsulating polymer. The exact amount of peptide can be determined by bioavailability assays. The formulations may contain the peptide in an amount between at least 0.2, preferably 0.5 and 20% by weight, based on the weight of the polymeric matrix, preferably from 2.0 to 10, especially from 3% to 5% by weight.

The release of the peptide from the microparticle can last from one to two weeks, up to 2 months.

Administered subcutaneously to a rat in a dose of 10 mg of somatostatin per kg of body weight of the animal, the delayed release formulation which conveniently comprises somatostatin, for example octreotide in a biocompatible, biodegradable polymeric carrier, has a concentration of blood plasma somatostatin at a minimum of 0.3 ng / ml, preferably less than 20 ng / ml over a period of time of 30 days or, eveniently 'over a period of time of 50 days ..

Alternatively, the delayed release formulation conveniently comprising a somatostatin, for example octreotide, in a biodegradable, polymeric, bioeompatible carrier, presents, when administered intramuscularly to a rabbit at a dose of 5 mg per kg of

body weight, a concentration of somatostatin of at least 0.3 ng / ml, over a period of time dias 50 days and, at the same time, a maximum concentration of 20 ng / ml '.

The further preferred properties of the obtained delayed release formulations, which contain somatostatin, for example octreetide, depend on the preparation processes employed. . ’

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Therefore, the invention also provides somatostatin compositions, preferably octreotide and octreotide analogs, which have the following properties:

1. a delay of at least 70%, preferably at least 74%, for example at least 75%, 80%, 83% or at least 89%, over a period of time from 0 to 42 or 43 days, and / or

2. an average plasma level (0 ideal ideal) of 2.5-6.5, preferably 4-6.5 ng / ml over a period of time from 0 to 42 days, in the rat, when administered by route subcutaneous and / or a mean plasma level of 3.5-6.5, eg 4-6.5 ng / ml over a period of time from 0 to 42 or 43 days, in the rabbit, when administer 5 mg of somatostatin intramuscularly, and / or

3. an ABC (area under the curve) over a period of time from 0 to 42 days, of at least 160, preferably 170-230 ng / ml x days, for the rat, when subcutaneously administering 10 mg of somatostatin, and / or water ATTO for a period of time from 0 to 42 or 43 days of at least 160, preferably from 180 to '275, for example from 200 to 275 ng / ml x days for the rabbit, when administer 5 mg of somatostatin intramuscularly.

For the quantitative characterization of the delayed release formulations described above, the area deviation (AB) method is used. published by MramerfalX and 1 «Posenthaler; item. d, Pharmaceut.

32, 1-6 (1986).

In summary, the AB method calculates the area of the profile deviations in the experimental plasma from an ideal profile that is a constant average level in the plasma (= ideal) produced, converting the experimental area under the curve. plasma level-time (ABO), to a rectangle of equal area.

From the percentage deviation of the area (referring to the area below the curve, the delay in $ is calculated as follows:

% of delay = 100 x (1 - AD / ATJC)

By the referred method, the entire plasma profile can be characterized by a single numerical index, measured during a period of time previously selected »

Ho Proc. natl. Acad. Know. USA 8 (1988) 5688-5692, a plasma level profile of the oepepeptide, a somatostatin analog, which has the formula «* D-Phe-Cys-Try-D-Trp-Dys-Tal-, is described in Figure 4 Cys-TrP-HHg in the rat. 1

However, a very clear comparison cannot be made with the plasma level data of the compositions of the invention, in the rat, mentioned above, since the indication of the plasma level profile was based on another method of administration. traction by intramuscular injection) and - what is most important - the level of microcapsule load (between 2% eS /) has not been fully indicated nor the amount of dosage for administration (portions of microcapsules of 25 to 50) »Intended for 30 days» although determinations have been made for at least 45 days). Furthermore, the type of poly (2XL-lactide-o-glycolide) used has not been fully described.

value indicated in the publication 'is too low to be accepted as a pre-publication that interferes with the invention.

The following examples illustrate the invention.

Polymers Ç is the average molecular weight,

shape determined by C-PC used, as a model, polystyrene.

EXAMPLE 1;

Dissolve in 15 ml of methylene chloride, with magnetic stirring, 1 g of poly (D, L-lactide-o-glycolide) (5Q / 50 molar, molecular weight = 45,000; polydispersity approx. 1,7); then 75 mg of Octreotide acetate dissolved in 0.5 ml of methanol are added. 1 mixture of. peptide-polymer, 15 ml of silicone oil (Dow 360 Medical Pluid 1000 es) Silicon © fluid are added ._ The resulting mixture is added to an emulsion, with stirring, which contains 400 ml of n-heptane, 100 ml of a phosphate buffering agent with a pH of 4.40 ml of Dow 360 Medical Iluid, 350 dogs and 2 ml of a Span 80 emulsifier. Continue to stir for at least 10 minutes. The resulting microparticles are recovered by vacuum filtration and dried overnight in an oven under reduced pressure. Approximately 90% * of microparticles are obtained having a size of the order of 10 to 40 microns *

The microparticles are suspended in a carrier and administered intramuscularly, in a dose of 4 mg of Octreotide, to New Zealand white rabbits. Blood samples taken periodically indicate plasma levels from 0.5 to 1.0 ng / ffil for 30 days, measured in the analyzes according to the radioimmunological test (RIA) (Radioimmunoassay).

saro 2;

σ

1 g of poly (D, L-lactide-o-glycolide) -glucose (molecular weight = 45,000 (55/45 molar, produced according to the process described in United Kingdom patent Ν ^δ) is dissolved with magnetic stirring »2 145 422 B; polydispersibility

approx. 1.7; produced from 0.2% glucose) in 25 ml of ethyl acetate; 75 mg of Octreotide dissolved in 3 ml of methanol are then added. To the peptide-polymer mixture, 25 ml of silicone oil (Dow brand 3β0 Medical ELuid, 1000 cs) are then added. The resulting mixture is added to the emulsion described in Example 1. It is continued to stir for at least 10 minutes. The resulting microparticles are removed by filtration under reduced pressure and dried overnight in an oven under reduced pressure. Thus, more than 80 / microparticles having a size of 10 to 40 microns are obtained.

The microparticles are suspended in a carrier and administered intramuscularly, in doses of 4 mg of octreotide, to white rabbits from New Zealand »Blood samples taken periodically indicate levels of 0.5 to 2 ng / ml for 21 days, according to the measurements made by SIA. (Radioimmunological test).

ΕΜΡΡΟ 3:

Add, with stirring, a solution of 1.5 g of Octreotide acetate in 20 ml of methanol to a solution of 18.5 g of poly- (D, D-laephido-co-glycolide) -glucose (50: 50 molar, molecular weight 45,000) and 500 ml of methylene chloride. The phase separation is carried out by adding 500 ml of Dow 360 ledical Pluiâ (1000 cs) and 8C0 ml of Dow 360 Medical Pluid (350 cs) to the peptide-polymer suspension. The resulting mixture is added to a stirred emulsion consisting of 1800 ml of n-heptane, 2000 ml of spherical water and 40 ml of Span 80. After stirring for 10 minutes, the myospheres are collected by filtration, under pressure. reduced.

Half of the product is dried overnight in an oven at 37 ° C, under reduced pressure. The level of methyl chloride

The other half of the product is washed by shaking with 1000 ml of ethanol containing 1 ml of Span 80. After stirring for one hour, ethanol is decanted and the microparticles are shaken with 1000 ml of n-heptane containing 1 ml of Span 80. After stirring. for one hour, collect the microparticles by filtration under reduced pressure and dry overnight in an oven at 37 ° C under reduced pressure. In this way, the residual methylene chloride level of the microparticles thus washed is reduced from 1.2% to 0.12%.

The combined yield of the product is 18.2 g (91%) of microparticles containing 5.6% Octreotide, with an average diameter of 24 microns and 1.5% residual heptane.

The microparticles are suspended in a carrier and injected intramuscularly, in a dose of 5 mg / kg of Octreotide, in white rabbits. Blood samples collected periodically indicate plasma levels of 0.3 to 7.7 ng / ml for 49 days according to RIA measurement.

Dissolve in 10 ml of methylene chloride, with magnetic stirring, 1 g of poly- (D, I »-lactide-co“ glycolide) glucose, molecular weight 46,000 (50:50 molar produced according to the procedure described in United Kingdom Patent 2,145,422 B, polydispersibility (approx. 1.7, produced from 0.2% glucose), then 75 mg of Octreotide dissolved in 0.133 ml of methanol are added. The said mixture is perfectly mixed with the aid of an Ultra-Turax, for one minute, at 20,000 revolutions per minute, thus obtaining a suspension of very small crystals of Octreotide in the polymer solution.

The suspension is sprayed by means of a turbine

at high speed (5iro Âtomizer) and the small droplets are dried in a jet of hot air, thus generating microparticles. The microparticles are collected by means of a cyclone ”and dried overnight in an oven, at room temperature, under reduced pressure.

the microparticles are washed for 5 minutes with 1/15 molar of acetate buffer agent at a pH of 4.0 and dried again in an oven at room temperature, under reduced pressure. After 72 hours, the microparticles (mesh size 0.125 mm) are sieved to obtain the final product.

The microparticles are suspended in a carrier and administered intramuscularly, in a dose of 5 mg / Eg of Octreotide, to white rabbits (Chinchilla-bastards), and subcutaneously, in a dose of 10 ffig / Eg, to rats males. Blood samples taken periodically indicate plasma levels of 0.3 to 10.0 ng / ml (5 mg dose) in rabbits and 0.5 to 0.7 ng / ml in rats, for 42 days, a measurement performed according to radioimmunological assay. (RIA).

SWRIO 5:

Microparticles are prepared by spray drying, proceeding as described in Example 4, with the only difference that Octreotide is suspended directly in the polymer solution without using methanol.

The microparticles are suspended in a carrier and are administered subcutaneously to male rats in doses of 10 mg / Eg Octreotide. Blood samples taken periodically show plasma levels of 0.5 to 10.0 ng / ml in rats, for 42 days, according to the measurement in analyzes according to the radioimmunological test (RIA).

Ί '

Β EMPLOYE:

Dissolve in 2.5 ml of methanol chloride, 1 g of poly (D »L-lactide-oo-glycolide) glucose, molecular weight (w) 4, 000 (50:50 molar produced according to the procedure described in UK Latent 2,145,422 Bj polydispersity of approximately 1.7, produced from 0.2% glucose); 75 mg of Octreotide dissolved in 0.125 mg of deionized water are then added. A perfect mixing of the mixture is carried out, for example, by means of an Ultra-Turax, for one minute at 20,000 revolutions per minute (Water / Oil phase inside).

1 g of Gelatin A is dissolved in 200 ml of deionized water at 50 ° C and the solution is cooled to 20 ° C (external water phase). The Water / Oil phase and the Water phase are intensively mixed with which the inner Water / Oil phase is separated into small droplets that disperse homogeneously in the outer Water phase. The resulting triple emulsion is slowly stirred for one hour, with which the methylene chloride is evaporated and the mierocapsules are hardened from the droplets of the inner phase. After sedimentation of the microparticles, the supernatant is suction filtered »the microparticles are recovered by filtration under reduced pressure and rinsed with water in order to remove the gelatin. The drying, sifting, washing and subsequent drying of the microparticles are carried out as described in Example 4 *

The microparticles are suspended in a carrier and administered intramuscularly to white rabbits (chinchilla-bastards) in a dose of 5 mg of Gctreóti & o by Eg of body weight »and subcutaneously in a dose of 10 mg / Eg to rats male. Blood samples taken periodically indicate plasma levels of 0.3 n 15.0 ng / ml (5 mg dose) in rabbits and 0.5 to 8.0 ng / ml in rats,

for 42 days, according to the measurements made by analysis in the radioimmune assay (EIA).

EXAMPLE 7t

Microparticles are prepared according to the triple emulsion technique, proceeding as described in Example 6, but with three differences, namely

1. instead of 0.125 ml of water used there, 0.25 ml of acetate buffer at a pH of 4.0 is used to prepare the Water / Oil phase;

2. the collected microparticles are rinsed with 1/45 molar of acetate buffer at a pH of 4.0, instead of rinsing them with water, as in Example S;

3. the subsequent washing of the microparticles is omitted;

EXAMPLE 8:

Microparticles are prepared according to the triple emulsion technique, proceeding in the same way as described in Example 7, with the only difference that the water / oil phase is separated using water containing 0.7 / (water / volume) of sodium chloride instead of the acetate buffer used there.

EXAMPLE 9:

Microparticles are prepared in the same manner as described in Example 6, with the only difference that the active substance compound is directly dispersed in the polymer solution, after which the resulting dispersion is mixed with the Water phase containing the gelatin.

EXAMPLE 10:

Ootreptide Pamoate

10.19 g of octreotide-free base (10 mH) and 3.88 g of erabonoic acid (10 mH) are dissolved in a liter of water / dioxane (1: 1). The reaction mixture is diluted and lyophilized to give octreotide pamoate hydrate as a yellow powder.

= + 7.5 ^{O 0} (c = 0.35 in dimethylformamide).

Pactor 5s 1.4 where the factor == the weight of the lyophilized product / / weight of the octreotide contained therein.

pamoate can replace the octreotide acetate present in the microparticles of Examples 1 to 9 and is characterized by excellent stability *

EXBHPSO 11:

1 g of poly (D, l. — lactide-oil-glycolide) (50:50 molar, molecular weight = 36,100) in 20 ml of methylene chloride is added with stirring to a 100 mg solution of kaleitonin in 1.5 ml of methanol. Phase separation is carried out by adding 20 ml of fluid silicone (Dow 360 Medical Eluiâ, 1000 es). The resulting mixture is added to a stirred emulsion composed of 100 ml of a phosphate buffer at pH 4, 400 ml of n-heptane, 4 ml of Spaa 80 and 40 ml of fluid silicone (Dow 360 Medical Eluid, 1000 es) . After stirring for 10 minutes, the microspheres are collected by filtration under reduced pressure and dried overnight in an oven at 37 ° C under reduced pressure. 1.1 g of microspheres containing about 5.9 g / calcitonin are obtained,

EXAMPLE 12:

With a magnetic stirring, add a solution of

3.9 g of poly (D, l-lactide-co-glycolide) (50/50 isolate, average molecular weight '44,300) in 140 ml of methylene chloride to 100 mg of lipresin. The dispersion is continued to stir for one hour and then 140 ml of fluid silicone (Dow 360 Medical liquid, 1000 es) and 2.5 ml of Span 80 are added. Then, mix to 2000 ml of heptane and stir for 10 minutes. The resulting microcapsules are collected by vacuum filtration, washed three times with heptane and dried for 10 minutes under suction, half the sample is washed with water for 10 minutes; the other half is left without washing * Both samples are then dried overnight and the oven at 30 ° C under reduced pressure. 10.65 g of microcapsules are obtained. The analysis of the washed sample shows 0.5% lipresine, that of the unwashed test shows 0.6% lipresin.

Claims (2)

CLAIM Q 0 Rg 15. - (Process for the preparation of formulations containing delayed-release water-soluble peptides, comprising microparticles consisting of an active substance in a polymeric, biocompatible and biodegradable carrier, characterized by the fact that it comprises the operations consisting of a) if the polymeric carrier material is dissolved in an appropriate solvent in which the active substance is insoluble; b) to the solution obtained in operation a) a solution of the active substance is added and dispersed in a solvent that is not solvent for the polymer used in the previous operation a); c) to the dispersion obtained in operation b) a phase-inducing agent is added in order to initiate the formation of the microparticles; d) to the mixture obtained in operation c) an oil-in-water type emulsion is added to harden the particles, and e) if microparticles are recovered * 25. - irocesso for the preparation of microparticles that comprise an active substance in a biocompatible and biodegradable vehicle, characterized by the fact that it comprises the following operations that consist of: (i) if a water-in-oil type emulsion is perfectly mixed, formed from an aqueous medium and a water-immiscible organic solvent, which in one phase contains the active substance and in the other phase contains a biocompatible and biodegradable polymer , with an excess of aqueous medium, containing an emulsifying substance and a protective colloid to form a water-in-oil type emulsion, and without adding to the said water-oil-water type emulsion any substance that retains the active substance , and without any intermediate operation to increase viscosity; (ii) the organic solvent is desorbed, and (iii) the resulting microparticles are isolated and dried. 3®. - Process for the preparation of microparticles that comprise a compound as an active substance in a bioeompatible and biodegradable polymer, characterized by the fact that it comprises the operations that consist of (i) if a suspension of an active substance compound formed from an active substance compound and an organic solvent immiscible with water and containing a biodegradable bio-compatible polymer is perfectly mixed with an excess of an aqueous medium containing an emulsifying agent and a protective colony to form an oil-in-water type emulsion, the compound constituting the active substance in the dispersed form in the oily component without adding any other substance likely to retain the active substance and without applying any intermediate operational phase aimed at increasing viscosity; (ii) if the organic solvent is desorbed; and (iii) isolating and drying the resulting microparticles. 4®. - Process for the preparation of microparticles, characterized by the fact that the following ingredients are perfectly mixed: a) a solution of an active substance in an aqueous medium and D) a solution of a polymer in an organic solvent that is not miscible with: the aqueous medium, and intensively mixing the water-in-oil type emulsion obtained in a) with solution b), with c) an excess of one aqueous medium containing a protective colloid, without adding any active substance retention substance to the water-in-oil emulsion, nor applying any intermediate operational phase in order to increase its viscosity, then harden the embryonic microparticles in the emulsion type water-in-oil-in-water by desorption and isolate produced microparticles. 5. ^A process according to claim 4, characterized in that the active substance is a somatatin. Process according to claim 4, characterized in that the active substance is the oepeptide of the formula (3) Phe-Cys-? He- (3) Trp-T _J ys-Shr-Cys-Thr-ol (whose name generic is oetreotide). 7. The process of claim 4 wherein the active substance is oetreotide pamoate. gs. Process according to claim 4 characterized in that the polymer is a polylactide-co-glycolide. 9®. Process according to claim 4, characterized in that the aqueous medium is water or a buffering agent. 1Q-. Change of accord according to claim 4, characterized in that the aqueous medium is a buffering agent with a pH in the range between 3 and 8. 11§. Process according to claim 4, characterized in that the organic solvent is methylene chloride. 12s. - Process for the preparation of microparticles, characterized by the fact that the following components are perfectly mixed: a) a solution of a somatostatin in water or a buffering agent in a weight / volume ratio between 0.8 to 4.0 g / 1 to 120 ml; and b) a solution of a polylactide-co-glycolide in a solvent orgânieo which is not miscible with the aqueous media in a ratio by weight / volume comprised in the _w range between 40 g / 90 to 400 ml, so that the weight ratio / '/ weight between the active substance and the polymer between 1/10 and 1/50 and the volume / volume ratio between the aqueous medium and the organic solvent is between 1 / 1.5 and 1/30, and if perfectly mix the water-in-oil type emulsion obtained by combining solutions a) and b), with c) an excess of water or a buffering agent containing.a protective eoloid in a volume / volume ratio a) b) c) comprised between 1/10 and 1: 100 »without adding any other retention substance to the water-in-oil type emulsion, nor to apply any intermediate operational phase to increase the viscosity, if the microparticles present in the water / oil / water emulsion formed by evaporation of the solvent are hardened and the microparticles produced are isolated . 13 ~. * Process according to claim 12, characterized in that the protective colloid is gelatin, 14 ~ * - Process for the preparation of mlcroparticles, characterized by the fact that the following components are perfectly mixed a) a solution to a somatostatin in an aqueous medium ^ in a weight / volume ratio equal to 2.5 g / 10 ml and b) a solution of a polylactide-co-glycolide in an organic solvent that is immiscible with the aqueous medium, in a weight / volume ratio equal to 40 g / ml in such a way that the weight / weight ratio between the active substance and the polymer is equal to 1/16 and the volume / volume ratio between the aqueous medium and the organic solvent is equal to 1/10; and if the water-in-oil type emulsion resulting from the addition of a) to b), mix perfectly c) an excess of an aqueous medium containing a protective colloid in a concentration between 0.01 and 15.0 / in a volume / volume ratio (ratio of mixed volumes) of ab) / c) equal to 1/40, without adding any other retention substance to the water-in-oil type emulsion or applying any intermediate operational phase to increase its viscosity; then »the microparticles existing in the water / oil / water type emulsion thus hardened by evaporating the solvent and isolating the microparticles produced. 15 ^ã . ~ Krocesso for the preparation of microparticles, characterized by the fact that the following components are perfectly mixed a) a solution of octreotion in a proportion by weight., / volume equal to 2.5 g / 10 ml in a buffering agent with a ρϊϊ between 3 and 3, and b) a solution of a polylactide-o-glieolide in methylene chloride, in a weight / volume ratio equal to 40 g / 100 ml, in such a way that the weight / weight ratio between the active substance and the polymer is 1/16 and the volume / volume ratio between the aqueous medium and the organic solvent is 1/10; and perfectly mix the water-in-oil type emulsion resulting from the addition of a) with b), with c) an excess of a buffer with a pH between 3 and 8, containing gelatin in a concentration equal to 0.5% by weight, a volume / volume ratio (ratio of mixed volumes) from ab) to e) equal to 1/40 without adding any other retention substance to the water-in-oil type emulsion, nor applying any intermediate operational phase to increase viscosity if the embryonic microparticles are hardened in the form of an emulsion type of water / oil / water by evaporation of methylene chloride and isolate the microparticles thus obtained. • j 16®. - Process for the preparation of a delayed-release pharmaceutical composition for the treatment or prevention of achromegaly or breast cancer, characterized by the fact that octreOtide or a salt or derivative thereof is mixed with a biocompatible and biodegradable carrier. 17®. Process according to claim 16, characterized in that, in said delayed release composition, poly (D _s X — wool-co-glycolide) glucose is used. 18®. Process according to claim 16, characterized in that the surface of the particles is substantially free of the compound that constitutes the active substance. 19 * 3. Process according to claim 16, characterized in that the compound constituting the active substance is mixed, a solution of said compound in methanol or in water or a buffering agent with a pH value between 3 and 8 ? with a solution of a polylactide-co-glycolide in methylene chloride; if the suspension, solution or emulsion of the active substance compound formed in the polymer solution is sprayed on a jet of hot air, the microspheres are collected and washed with a solution of the buffering agent with a pH value between 3.0 and 8 , 0 or with distilled water and dry under reduced pressure at a temperature between 20 and 40 0. 20th. Process according to claim 16, characterized in that an amount of octreotide is used such that its concentration in the composition and delayed release is within the range of 2.0 s to 10% by weight * 2nd. Process according to claim 16, characterized in that the microparticles have a diameter in the range between 1 and 250 micrometers. 223. - Process for the preparation of delayed-release formulations, characterized by the fact that a peptide as an active substance is mixed with a polylactide-co-glycolide ester 40/60 to ÓO / 40 polyol, choosing the unit of The polyol of the group with its carbon atom chain in (C4 -Og) contains alcohol with 3 to 6 hydroxyl groups and a monosaccharide or in "disaccharide", with the polyol esterifying at least 3 chains of the polylactide-co-glycolide. 23 ^δ · - process for the preparation of delayed-release formulations, characterized by the fact that the active substance employs a peptide chosen from the group formed by somatostatin, calcitonin and lipresis, incorporated in a linear polymer of.pollláeiido-co-glieólldo 40/50 to 60/40, said polymer having chains with a mass average molecular weight (Kw) between 25 000 and 100 000, a polydispersity between 1.2 and 2 at a concentration between 0.2 and 10% by weight of the peptide as active compound in said polymer. 24. A process according to claim 22, characterized in that a polymer having a mass average molecular weight (Sw) in the range between 10 000 and 200 000 and a polydispersity in the range between 1, 7 and 3.0. 25. The method of claim 22, wherein said polymer has an average molecular weight (W) in the range of 35,000 to 60,000. 26§. Process according to claim 22, characterized in that the ISv / Mn polydispersity is in the range between 2.0 and 2.5. 27 ^§ . Process according to any of claims 16, 22 or 23? characterized in that the said delayed-release formulation, after being administered subcutaneously to a rat with a dose of 10 mg of active compound per kg of body weight, gives rise to a concentration of the compound that constitutes the active substance in blood plasma equal to at least '0.3 ng / ml and less ί-: * 20 ng / ml over a period-, 30 days * ggg - Process according to any of claims 16, 22 or 23, character bristled by the fact that the said delayed-release composition, after being administered to a rabbit, intrasuscularly, with a dose of 5 mg of active substance per hg of body weight, gives an active substance concentration of at least 6, 3 ng / mi and a maximum of 20 ng / ral during a period of $ 0 days * 29® A process according to any of claims 16, 22 or 23, characterized in that it mentions * the delayed-release composition, after being administered subcutaneously to a rat with a dose of 5 mg of compound of active substance per kg of body weight, give rise to an average plasma level (ideal Cp) between 2.5 and 6.5 ng / ml over a period of 0 to 42 days, ^£ 30 ~ proeesso according to claims 16, 22 or 23, characterized in that said delayed-release composition after being administered to a rat with a dose of 5 mg of active substance per kg of body weight, gives rise to an average level of active substance in the plasma (ideal option) comprised between 2.5 and 6.5 ng / ml over a period of time from 0 to 42 days » 31 - Ercesse according to any of claims 16, 22 or 23, characterized in that said delayed-release composition, after being administered to a rabbit, intramuscularly, with a concentration of 5 g of substance active per kg of body weight, originating 'at medium level in plasma (sp ideali) between 3.5 to 6.5 rg / ffil, 32® * Process according to any of claims 16, 22 or 23, characterized in that it mentions it of the delayed-release composition, after being administered subcutaneously to a rat with a dose of XO mg of substance compound active per kg body weight »present ums (area under the curve) (âUo) between 160-230 ng / ml x days» for a period of time from 0 to 42 or 43 days » 33® - Process according to any of claims 16, 22 or 23 »characterized in that the said delayed-release composition, after being administered, to a rabbit» by intramuscular route »with a dose of 5 mg of active substance per kg body weight »present a value of (area under the curve) (AUC) between» 160 and 275 ng / ml x days »for a period of time from 0 to 42 or 43 days» ^£ 34 - Process for the preparation of delayed release compositions »characterized by the fact that a peptide is mixed as an active substance that can be chosen from the group formed by calcitonin and lipresine © and their pharmaceutically acceptable salts with a bioconpatible and biodegradable polymer matrix» 35 & «. Process according to claim 23, characterized in that, in the said delayed-release composition, a peptide chosen from the group of calcitonin and lipresin is used as the active substance * 36® - IToeessõ for the preparation of octreotide pamoate, characterized by the fact that octreotide is reacted with embonic acid or one of its reactive derivatives *