Method for producing peptide salts

Abstract

This disclosure relates to a method for preparing pharmaceutically acceptable peptide salts, particularly salts of atosiban (e.g., atosiban pamoate). This disclosure further extends to the preparation of particles of such salts, for example, via a spray-drying process.

Description

[Technical Field]

[0001] This disclosure relates to methods for preparing peptide salts, particularly pharmaceutically acceptable peptide salts such as salts of atosiban. The disclosure further extends to the preparation of particles of such salts, for example, via a spray-drying process. The disclosure further relates to peptide salts and particles of such salts produced by these methods. [Background technology]

[0002] Atosiban is a synthetic peptide that acts as an inhibitor of oxytocin and vasopressin. The literature describes atosiban as having many therapeutic uses, including as a uterine contraction inhibitor (e.g., to delay and / or prevent premature birth). Atosiban has the following structure: [ka]

[0003] Atosiban contains a free base and can form an acid addition salt. For example, atosiban can form an acid addition salt with acetic acid to provide atosiban acetate. Atosiban acetate is marketed under the brand name Tractocile® for use in delaying preterm birth.

[0004] Pamoic acid is an organic acid that can be used to form acid addition salts. The chemical name of pamoic acid is 4,4'-methylene-bis(3-hydroxy-2-naphthoic acid). Its structure is shown below: [ka]

[0005] Chinese Patent Application Publication No. 114249800A (SHENZHEN SHENYIN PHARMACEUTICAL CO LTD) describes a method for preparing polypeptide pamoates. This method involves the use of a chromatography column having a reversed-phase polymer packing as the stationary phase. The column must be equilibrated before packing with the peptide solution, and then a specific ratio of an aqueous solution of the inorganic pamoate salt and an organic solvent are packed onto the column to allow ion exchange to be carried out on the column. Chinese Patent Application Publication No. 114249800A describes that its chromatography method results in better control of impurities, ions, and / or solvent residues in the resulting salt. [Overview of the project] [Means for solving the problem]

[0006] This disclosure is based on the finding that atosiban pamoate can be prepared by a precipitation method. Surprisingly, the inventors have confirmed that the atosiban pamoate produced by the disclosed precipitation method yields a high-purity compound without requiring complex processing and / or purification steps. Such a method may be particularly suitable for scaling up for production.

[0007] Therefore, according to the first embodiment, a method for preparing atosibampamoate, (i) Contact and / or react the first atosiban salt and the inorganic pamoate together. Includes, This invention provides a method for forming atosiban pamoate as a precipitate.

[0008] The first atosiban salt can be any suitable atosiban salt that is soluble in a solvent in which atosiban pamoate is insoluble (e.g., under the temperature and pressure conditions in which the reaction occurs). The first atosiban salt is not atosiban pamoate. In some examples, the first atosiban salt may be a salt having a solubility of at least 10 mg / mL in aqueous solution at 25°C. Typical examples include the first atosiban salt being selected from atosiban acetate, atosiban hydrochloride, and atosiban rifluoroacetate.

[0009] As an example, the method may involve contacting a first atosiban salt (e.g., atosiban acetate) and an inorganic pamoate under conditions that enable them to react. For example, the first atosiban salt (e.g., atosiban acetate) and the inorganic pamoate may be contacted and / or reacted together in a reaction mixture (e.g., a suspension or solution).

[0010] In particular, under the conditions disclosed herein, an ion exchange reaction may occur when a first atosiban salt (e.g., atosiban acetate) is contacted with and / or reacted together with an inorganic pamoate in a reaction mixture (e.g., a solution), after which atosiban pamoate may precipitate. Surprisingly, the inventors have found that this precipitation method can yield a high-purity atosiban pamoate product. This method for providing atosiban pamoate improves ease of production while maintaining a good level of purity.

[0011] Suitable solvents for forming the reaction mixture (e.g., solution) used in the methods described herein include aqueous solutions. In some examples, the solvent may be water, for example, deionized water. Further examples of suitable solvents include aqueous buffer solutions, such as sodium phosphate buffer, phosphate-buffered saline (PBS) buffer, Tris buffer (tris(hydroxymethyl)aminomethane buffer), and HEPES (2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid) buffer.

[0012] In some cases, this method (i) Providing a solution of a first atosiban salt (e.g., atosiban acetate); (ii) Contacting the solution of the first atosiban salt (e.g., atosiban acetate) with an inorganic pamoate; which may be included, Atosiban pamoate is formed as a precipitate.

[0013] In some examples, the method further includes preparing a solution of the first atosiban salt, e.g., preparing a solution of atosiban acetate. For example, the solution of the first atosiban salt can be prepared by adding the first atosiban salt into any suitable solvent and / or dissolving it in any suitable solvent. Suitable solvents for use in preparing the solution of the first atosiban salt include any of those described herein (e.g., an aqueous solution such as water (e.g., deionized water)). As a further example, suitable solvents can include aqueous buffer solutions such as sodium phosphate buffer, phosphate buffered saline (PBS) buffer, Tris buffer (Tris(hydroxymethyl)aminomethane buffer), and HEPES (2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid) buffer.

[0014] The concentration of the first atosiban salt (e.g., atosiban acetate) in the solution can be from about 0.05% w / v to about 50% w / v, from about 0.1% w / v to about 20% w / v, from about 0.5% w / v to about 10% w / v, or from about 1% w / v to about 5% w / v. In some examples, the concentration of the first atosiban salt (e.g., atosiban acetate) in the solution can be from about 1.5 w / v% to 4 w / v%. In yet another example, the concentration of the first atosiban salt (e.g., atosiban acetate) in the solution can be about 2.5% w / v or about 3.3% w / v. The reference to concentration can refer to the concentration of the first atosiban salt (e.g., atosiban acetate) in the starting solution and / or the concentration of the first atosiban salt (atosiban acetate) in the solution after the addition of the metal pamoate (e.g., when the volume increases due to the addition of the pamoic acid inorganic substance in solution form).

[0015] In the disclosed method, useful inorganic pamate salts may include metal pamate salts. Examples of metal pamate salts that can be used in the methods disclosed herein include alkali and alkaline earth metal pamate salts. Representative examples include, but are not limited to, sodium pamate and potassium pamate. In certain examples of the present disclosure, the metal pamate salt can be sodium pamate.

[0016] The step of contacting a solution of a first atosiban salt (e.g., atosiban acetate) with an inorganic (e.g., metal) pamate salt can include adding the inorganic pamate salt to the solution of the first atosiban salt. The inorganic pamate salt can be added in the form of a solution or a suspension. By way of example, a solution of an inorganic pamate salt can be prepared by adding a pamic acid inorganic to any suitable solvent and / or dissolving it in any suitable solvent.

[0017] Suitable solvents for use in the preparation of a solution of an inorganic pamate salt include aqueous solutions. In some examples, the solvent can be water, such as deionized water. As a further example, suitable solvents can include aqueous buffer solutions such as sodium phosphate buffer, phosphate buffered saline (PBS) buffer, Tris buffer (Tris(hydroxymethyl)aminomethane buffer), and HEPES (2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid) buffer.

[0018] The concentration of the inorganic pamate salt in the solution can be from about 0.01% w / v to about 50% w / v, from about 0.05% w / v to about 20% w / v, from about 0.1% w / v to about 10% w / v, or from about 0.25% w / v to about 5% w / v. In some examples, the concentration of the inorganic pamate salt in the solution can be from about 0.5% w / v to 4% w / v. In another example, the concentration of the inorganic pamate salt in the solution can be about​​​​​​​The molar ratio of the first atosiban salt (e.g., atosiban acetate) to the inorganic pamoic acid used in the reaction, in contact with and / or reacted together, may be 10:1 to about 1:10, for example, about 5:1 to about 1:5 or 3:1 to 1:3. In some examples, the molar ratio of the first atosiban salt to the inorganic pamoic acid used in the reaction, in contact with and / or reacted together, may be about 2.5:1 to about 1:1, for example, about 2.1:1 to about 1.1:1.

[0021] In some cases, a solution of an inorganic pamoate (e.g., an aqueous solution of sodium pamoate) can be added to the solution of the first atosiban salt little by little and / or gradually increasing in volume. In a further example, a solution of an inorganic pamoate can be added to the solution of the first atosiban salt dropwise.

[0022] During the addition of inorganic pamoates (which may be added selectively in the form of solutions outlined above), the resulting reaction mixture can be continuously stirred, for example, to aid in and / or facilitate the ion exchange reaction.

[0023] This method can be carried out under any conditions suitable for promoting and / or accelerating the ion exchange and / or precipitation of atosiban pamoate from the reaction mixture (e.g., solution). This method can be carried out under ambient conditions. For example, this method can be carried out at room temperature and / or atmospheric pressure.

[0024] In some cases, this method can be carried out at temperatures above approximately 0°C, above approximately 10°C, or above approximately 15°C. In some cases, this method can be carried out at temperatures between approximately 0°C and approximately 100°C. For example, this method can be carried out at temperatures between approximately 10°C and approximately 50°C or between approximately 15°C and approximately 35°C. In some cases, this method can be carried out at or around room temperature (for example, at temperatures between approximately 18°C ​​and approximately 27°C or between approximately 20°C and approximately 25°C).

[0025] In some cases, this method can be performed under atmospheric pressure, for example, in the range of 101.325 kPa or 1 atmosphere.

[0026] A suitable solvent for the freeze-drying stage may be any solvent such that the solubility of atosiban pamoate is at least 20 mg / mL (e.g., at 25°C). Preferably, the solvent for the freeze-drying stage may also have a melting point of at least -80°C. A suitable solvent for the freeze-drying stage may include a mixture of acetonitrile and water. As a typical example, the solvent for the freeze-drying stage may be or may include a mixture of acetonitrile and water in any ratio from 1:10 to 10:1 (v / v) (e.g., in an acetonitrile / water (1 / 2, v / v) mixture).

[0027] In a further embodiment, atosibane pamoate prepared according to the method described herein is provided. In particular, using the method disclosed herein, the inventors have shown that specific salt forms of atosibane pamoate can be obtained. In particular, in some examples, the atosibane pamoate provided by the method of the present disclosure may be a semi-salt.

[0028] Accordingly, according to further aspects of this disclosure, an atosiban pamoate is provided in which the molar ratio of atosiban to pamoic acid in the salt is about 2:1.

[0029] The stoichiometric atosibampamoates described herein may enable a higher drug load than the monosalt form, which may facilitate a reduction in formulation volume when the salt is formulated for pharmaceutical use (and thus may help improve patient compliance in clinical settings).

[0030] In some cases, it may be desirable to provide atsiban pamoate in particulate form (e.g., as particles). For example, injectable formulations generally require particles of suitable and / or uniform size. One option for providing such particles is by using spray drying technology.

[0031] Therefore, the method described herein may further include the step of spray-drying atosiban pamoate to provide atosiban pamoate particles.

[0032] Therefore, according to further aspects of this disclosure, a method for providing pamoate atsiban particles, (i) To provide a loading solution of atsiban pamoate; (ii) Spray-drying the loading solution to form pamoic acid atsiban particles, A method including this is provided.

[0033] As used herein, spray drying may refer to a process in which a dry powder (e.g., containing a compound) is formed from a liquid. A spray drying process typically involves atomizing a solution (referred to herein as the “loading solution”) by spraying, followed by the rapid evaporation of the atomized droplets into a solid powder by a high-temperature gas.

[0034] For a spray-drying process to be effective, several factors must be harmonized. One such factor is the identification of a suitable loading solution for the compound to be spray-dried. Preferably, the loading solution should be volatile at a temperature at which the compound remains stable. The compound should exhibit moderate solubility in the solvent and also exhibit a good level of stability during the spray-drying process. The latter point may be particularly important when manufacturing the compound on an industrial scale, for example, when the compound can be left in the solution for a longer period before the spray-drying stage. The need for stability becomes more important for compounds intended for use in pharmaceutical formulations where purity is extremely important (such as atsiban pamoate). Furthermore, the use of this loading solution in the spray-drying process itself should preferably result in suitable and / or uniformly sized particles with good appearance and needle passageability (e.g., if the particles are intended for use in injectable formulations).

[0035] The inventors faced difficulties in identifying a suitable loading solution for atosiban pamoate for use in spray drying, such as one that provides at least an acceptable level of solubility while balancing the need to maintain a good level of stability in the loading solution. In other words, a loading solution compatible with atosiban pamoate to provide a reproducible and reliable spray drying process suitable for scaling up production.

[0036] In particular, the inventors identified a group of loading solutions in which atosiban pamoate can exhibit good levels of solubility and stability. The loading solutions may also exhibit suitable volatility for spray drying of atosiban pamoate and / or can be used to provide suitable and / or uniformly sized particles (for example, for therapeutic applications).

[0037] In particular, atosiban pamoate may have a solubility in loading solutions of at least about 15 mg / mL, at least about 20 mg / mL, or at least about 25 mg / mL. In some cases, atosiban pamoate may have a solubility in loading solutions of about 15 mg / mL to 100 mg / mL, about 20 mg / mL to 75 mg / mL, or about 20 mg / mL to 60 mg / mL. Solubility is measured at room temperature and atmospheric pressure, as described herein.

[0038] Atsiban pamoate may exhibit a good level of stability in the loading solution (for example, when stored in the loading solution before the spray-drying stage).

[0039] As used herein, the expression “good level of stability” may mean that atsiban pamoate present in a loading solution such as those described herein is substantially stable and / or exhibits minimal or no degradation.

[0040] In particular, if atsiban pamoate is stored for at least 1 hour, at least 2 hours, at least 3 hours, or at least 4 hours, it may be substantially stable in the disclosed loading solution and / or exhibit minimal or no degradation. In other examples, if atsiban pamoate is stored for at least 12 hours, at least 24 hours, at least 36 hours, or at least 48 hours, it may be substantially stable in the disclosed loading solution and / or exhibit minimal or no degradation. In further examples, if atsiban pamoate is stored for at least 1 day, at least 2 days, at least 3 days, or at least 4 days, it may be substantially stable in the disclosed loading solution and / or exhibit minimal or no degradation. In these examples, the loading solution may be stored at room temperature or under refrigerated conditions. In particular, the loading solution can be stored at room temperature (e.g., about 15°C to about 30°C, e.g., about 20°C to about 25°C) and / or at atmospheric pressure.

[0041] As used herein, “stable” may mean that, when stored in a loading solution, atosiban pamoate can maintain at least about 98.9%, at least about 99.0%, at least about 99.1%, at least about 99.2%, at least about 99.3%, at least about 99.4%, or at least about 99.5% of its original purity level.

[0042] The loading solution may exhibit a level of volatility suitable for spray drying of atsiban pamoate. In some examples, the loading solution may have a boiling point of about 150°C or less, about 125°C or less, or about 100°C or less.

[0043] The step of providing a loading solution of pamoate atsiban may include preparing a loading solution of pamoate atsiban. For example, a loading solution of pamoate atsiban may be prepared by adding pamoate atsiban to any suitable solvent as described herein and / or dissolving it in any suitable solvent.

[0044] In some cases, the loading solution may contain one or more solvents, such as two, three, or four solvents. In some cases, the loading solution may contain two solvents.

[0045] One or more solvents may be selected from alcohols, water, and acetonitrile. The alcohol may be saturated or unsaturated. Branched or linear alcohols may be used. Suitable alcohols include, but are not limited to, C1-C6 alcohols or C1-C4 alcohols. Representative examples of suitable alcohols include, but are not limited to, methanol, ethanol, isopropanol, n-propanol, isobutanol, sec-butanol, tert-butanol, pentanol, and hexanol.

[0046] In some cases, the loading solution may contain alcohol (e.g., methanol).

[0047] In particular, the loading solution may contain alcohol and water. As a further example, the loading solution may contain methanol and water, or ethanol and water.

[0048] In other examples, the loading solution may contain acetonitrile and water.

[0049] In particular, in some examples, the loading solution may comprise (i) an alcohol (e.g., a C1-C4 alcohol such as methanol); (ii) an alcohol (e.g., a C1-C4 alcohol such as methanol) and water; and (iii) a solvent system selected from acetonitrile and water. In particular, the inventors have shown that using such a solvent system can provide an effective loading solution for atosiban pamoate, resulting in both good levels of solubility and volatility while maintaining a good level of stability for atosiban pamoate. In yet another example, the loading solution may comprise (i) an alcohol (e.g., methanol) and water; and (ii) a solvent system selected from acetonitrile and water.

[0050] If two or more solvents are present in the loading solution, they may be present in any preferred ratio that provides a suitable level of volatility, solubility, and / or stability for atosiban pamoate. In some examples, if two solvents are present, they may be present in any ratio (volume of first solvent:volume of second solvent) of about 100:1 to about 1:100, about 10:1 to about 1:10, or about 1:5 to about 5:1.

[0051] As a further example, if the loading solution contains alcohol (e.g., C1-C4 alcohol such as methanol) and water, the two solvents may exist in any ratio of about 10:1 to about 1:10 in terms of volume of alcohol (e.g., C1-C4 alcohol such as methanol):volume of water. In some examples, the loading solution may contain alcohol (e.g., C1-C4 alcohol such as methanol):water (v / v) in any ratio of about 1:1 to about 10:1, or about 2:1 to about 8:1, or about 3:1 to about 7:1. In some examples, the loading solution may contain alcohol (e.g., C1-C4 alcohol such as methanol):water (v / v) in a ratio of approximately 5:1.

[0052] As a further representative example, if the loading solution contains acetonitrile and water, these two solvents may exist in a ratio of approximately 10:1 to approximately 1:10 in terms of volume of acetonitrile to volume of water. In some examples, the loading solution may contain any ratio of acetonitrile to water (v / v) of approximately 1:1 to approximately 10:1, or approximately 1:1 to approximately 5:1, or approximately 2:1 to approximately 4:1. In some examples, the loading solution may contain approximately 3:1 acetonitrile to water (v / v).

[0053] As described above, the method includes a step of spray-drying the disclosed loading solution to form atosiban pamoate particles (which may also be referred to herein as atosiban pamoate spray-dried particles).

[0054] The spray drying step can be carried out using any of the spray drying systems known in the art.

[0055] A spray dryer typically includes a drying chamber into which a liquid feed (e.g., a loading solution as described above) is introduced via an inlet. This inlet generally takes the form of an atomizer. A drying gas is also introduced into the drying chamber, which causes the loading solution to evaporate, leaving behind solid particles (e.g., solid particles of atosiban pamoate). These solid particles can typically be separated using a particle separator (e.g., a cyclone) and collected in a container. An overview of the spray drying process in the pharmaceutical industry can be found in "Gaspar et al, European Pharmaceutical Review, 28 October 2014, “Spray drying in the pharmaceutical industry.” As a typical example, the spray drying stage can be carried out by a mini spray dryer 290 (Buchi, Switzerland).

[0056] In some cases, during the spray drying stage, the inlet temperature (e.g., the temperature of the dry air at the inlet to the drying chamber) is approximately 50°C. o The temperature can be approximately 150°C, 75°C to 125°C, 90°C to 110°C, or 95°C to 105°C. In some cases, the inlet temperature is approximately 100°C. o It could be °C.

[0057] In some cases, during the spray-drying stage, the supply rate (e.g., the rate at which the loading solution is introduced into the atomizer before entering the drying chamber) may be approximately 0.5 mL / min to 20 mL / min, 1 to 10 mL / min, or 2 to 7 mL / min. In some cases, the supply rate may be approximately 3 mL / min to 6 mL / min. In yet another example, the supply rate may be approximately 4 mL / min.

[0058] In some examples, during the spray drying step, the flow rate of the spray gas (e.g., the rate at which the spray gas is introduced into the atomizer) may provide a reading height in a gas flow meter between about 10 and about 100 mm, about 25 mm to 75 mm, or about 30 mm to 50 mm. In some examples, the spray gas flow rate may be about 40 mm. As used herein, "mm" is the unit of height as a reading in a gas flow meter. The unit of height can be converted to the actual spray gas volume flow rate under standard temperature and pressure conditions. By way of example, a height of 40 mm may correspond to an actual gas volume flow rate of 667 L / h. Thus, in some examples, the spray gas flow rate may be about 283 L / h to about 1744 L / h, about 355 L / h to about 1374 L / h, or about 439 L / h to about 1052 L / h.

[0059] In some examples, during the spray drying step, the drying gas flow rate (e.g., the rate at which the drying gas is introduced into the drying chamber) is about 1 m 3 / h to about 100 m 3 / h, about 10 m 3 / h to about 75 m 3 / h, about 20 m 3 / h to 50 m 3 / h. In some examples, the drying gas flow rate may be about 35 m 3 / h.

[0060] The pamoic acid atosiban particles produced by the spray drying process may include a substantially spherical or nearly spherical shape. The spray dried pamoic acid atosiban particles produced by the methods described herein (and using a loading solution) may include a diameter of about 0.1 to about 50 μm (micrometers), such as about 0.5 μm to about 25 μm, or about 1 μm to 10 μm. In particular, the spray dried pamoic acid atosiban particles produced by the methods described herein (and using a load solution) may include a diameter of about 1 μm to 8 μm. The spray dried pamoic acid atosiban particles as described herein may have specific applications in injectable formulations.

[0061] After the spray-drying stage, the purity of atosiban pamoate present in the particles may be at least about 90%, at least about 95%, at least about 97%, or at least about 99% (based on the total weight of the particles).

[0062] Further aspects of this disclosure provide atosiban pamoate particles that can be obtained by the method disclosed herein.

[0063] A loading solution comprising atosiban pamoate in any one of the loading solutions described herein is further provided.

[0064] As a specific example, a loading solution for a spray-drying process is provided, comprising atosiban pamoate and a solvent system selected from (i) an alcohol (e.g., a C1-C4 alcohol such as methanol) in a ratio of about 5:1: water (v / v) and (ii) an acetonitrile in a ratio of about 3:1: water (v / v).

[0065] The methods described herein may have particular applications in the preparation of atosiban pamoate for use in pharmaceutical compositions. Such pharmaceutical compositions may contain atosiban pamoate together with one or more additional carrier components such as diluents, excipients, buffers, flavoring agents, binders, surfactants, thickeners, lubricants, and preservatives (including antioxidants).

[0066] definition In this disclosure, many terms are referenced and, unless otherwise indicated by the context, are understood to have the meanings provided below. The nomenclature used herein to define compounds, in particular the compounds described herein, follows the rules of the International Union of Pure and Applied Chemistry (IUPAC) relating to compounds, in particular the "IUPAC Compendium of Chemical Terminology (Gold Book)" (see AD Jenkins et al. Pure & Appl. Chem., 68, 2287-2311 (1996)). To avoid any doubt, if the IUPAC rules conflict with the definitions provided herein, the definitions herein shall prevail.

[0067] As used herein, the term "approximately" when limiting a numerical value may refer to a value within ±5% of the specified value. For example, if a particle is described as having a diameter of approximately 50 μm, the range of 47.5 μm to 52.5 μm is included.

[0068] In addition, as used herein, when any range is described as being between a lower and an upper limit, the defined range includes the defined endpoint (and therefore includes both the lower and upper limits).

[0069] isotope labeled compounds This disclosure also encompasses various deuterated forms of atosiban pamoate and any other compounds as described herein. Each available hydrogen atom bonded to a carbon atom can be independently replaced with a deuterium atom. Those skilled in the art know how to synthesize the deuterated forms of the compounds disclosed herein, including those mentioned above. For example, deuterated materials such as alkyl groups can be prepared by the prior art (see, e.g., methyl-d3-amine, available from Aldrich Chemical Co., Milwaukee, WI, catalog numbers 489, 689-2).

[0070] Apart from the fact that one or more atoms are substituted by atoms having atomic masses or mass numbers different from those most commonly found in nature, the disclosure also includes isotope-labeled compounds of the disclosure. Examples of isotopes that may be incorporated into the compounds of the disclosure include isotopes of hydrogen, carbon, nitrogen, oxygen, fluorine, iodine, and chlorine, for example, 3 H, 11 C, 14 C, 18 F, 123 I or 125 Including I, etc. The compounds of this disclosure and pharmaceutically acceptable salts of such compounds containing the aforementioned isotopes and / or other isotopes of other atoms are within the scope of this disclosure. Isotope-labeled compounds of this disclosure, for example, 3 H or 14Products incorporating radioactive isotopes such as 13C are useful in drug and / or substrate tissue distribution assays. Tritium-labeled isotopes, i.e. 3 H isotope, and carbon-14, that is 14 13C isotopes are particularly preferred due to their ease of preparation and detectability. 11 C and 18 The fluorine isotope is particularly useful in PET (positron emission tomography).

[0071] Throughout this specification, the term “comprising” is used to indicate that embodiments of the present invention “comprise” the features described, and therefore, it should be noted that other features may also be included. However, in relation to the present invention, the term “comprising” may also include embodiments of which the present invention “consists essentially of” or “consists of” the relevant features.

[0072] Detailed explanation The present disclosure will be further explained here by reference to the following non-limiting examples. [Brief explanation of the drawing]

[0073] [Figure 1] 1H NMR spectrum of atosiban acetate. [Figure 2] 1H NMR spectrum of atosiban pamoate prepared according to the exemplary method of this disclosure. [Figure 3] UPLC assay of pamoate atsiban powder prepared by the exemplary method of the present disclosure. [Figure 4] UPLC assay of spray-dried pamoate atsiban particles prepared by an exemplary spray-drying method of the present disclosure. [Figure 5] Scanning electron microscope (SEM) images of freeze-dried atsiban pamoate (left (500x), right (1000x)). [Figure 6]Scanning electron microscope (SEM) images of spray-dried atsiban pamoate particles (left (3000x), right (5500x)). [Modes for carrying out the invention]

[0074] Part A: Chemistry - Materials and Methods Unless otherwise specified, all chemicals used were commercially available and used without further purification.

[0075] NMR analysis NMR data were acquired using a Bruker Avance NEO 400 MHz NMR spectrometer (Bruker, US). Chemical shifts are reported in ppm relative to dimethyl sulfoxide (δ2.50), as shown in the NMR spectral data. For sample preparation, small amounts (1-5 mg) of the sample (atosiban acetate or atsiban pamoate) were dissolved in DMSO-d6 (0.6 ml) and transferred to test tubes for NMR analysis. All experiments were conducted at a temperature of 25°C.

[0076] Ultra-high-performance liquid chromatography (UPLC) analysis UPLC was performed on a Waters Acquity UPLC H-class system (Waters, US) equipped with a Waters Acquity UPLC® BEH Phenyl 1.7 μm, 2.1 x 100 mm column. The UPLC parameters are listed below:

[0077] [Table 1]

[0078] The UPLC moving phase gradient was as follows:

[0079] [Table 2]

[0080] Scanning electron microscopy (SEM) analysis: SEM was performed using a Phenom® Pure transmission electron microscope (Thermo Fisher Scientific, US). For sample preparation, spray-dried powder was directly dispersed onto a carbon adhesive, excess powder was removed by blowing a jet of particle-free compressed gas onto each sample, and then coated with gold-platinum under high vacuum. SEM images were recorded by digital processing at higher magnification. Particle size was determined by examining the micrographs using a built-in measuring tool.

[0081] A.1 Preparation of atosiban pamoate Atosiban pamoate was prepared by precipitation. 5 g atosiban acetate (based on 94.5% free base, MW=994.5 Da) was dissolved in 150 mL of deionized (DI) water. Separately, 1.15 g sodium pamoate (Na2 pamoate; MW=432.34 Da, acid-to-base molar ratio 1.1) was dissolved in 50 mL of deionized (DI) water. Mixing was performed by adding the atosiban acetate solution dropwise to the sodium pamoate solution in a 500 mL beaker at room temperature while continuously stirring with an overhead stirrer. A precipitate formed during continuous stirring, and stirring was continued at room temperature for a further 4 hours. The gel-like precipitate was quickly rinsed twice with deionized (DI) water and redissolved in an acetonitrile / water (1 / 2, v / v) mixture. Finally, the redissolved atosiban pamoate solution was pre-frozen at -40°C for 24 hours, and then placed in a freeze-dryer for 72 hours to obtain atosiban pamoate in powder form.

[0082] To confirm the success of the synthesis of atosiban pamoate, 1 The synthesized products were analyzed using 1H-NMR and UPLC. Equilibrium solubility tests were conducted to verify the change in the solubility of atosiban in aqueous media after hydrophobic counterion exchange.

[0083] The stoichiometry of the starting material atosiban:acetate is, 1¹H NMR (DMSO-d6) determined the ratio to be approximately 0.93:1, which indicates that atosiban acetate was a monoacetate (see Figure 1).

[0084] The stoichiometry of atosiban:pamoate is, 1 The ratio was determined to be 1:0.5 by 1H NMR (DMSO-d6) (see Figure 2). No acetate signal was observed, suggesting that the pamoate of atosiban was formed as a semi-pamoate.

[0085] Figure 3 shows UPLC graphs of atosiban acetate (upper curve) and atosiban pamoate (lower curve). UPLC analysis was performed according to the method outlined in the "Materials and Methods" section, and it is shown that the purity of atosiban pamoate is nearly 100%. (Note that in the UPLC curve for atosiban pamoate, the peak at approximately 2.6 min is for free atosiban base, while the peak at approximately 6.6 min is for pamoic acid). In contrast, since acetic acid does not produce a peak under the experimental conditions, only the free atosiban base peak is present at approximately 2.6 min in the curve for atosiban acetate.

[0086] A.2 Equilibrium solubility test: The results of equilibrium solubility tests for atosiban acetate and atosiban pamoate in phosphate-buffered saline (PBS) solution are shown in Table 1 below.

[0087] [Table 3]

[0088] The approximate solubility of atosiban acetate in PBS solution (pH=7.4) at room temperature (approximately 25°C) exceeded 197 mg / mL. Atosiban acetate showed high solubility (>60 mg / mL), and this solution remained clear after shaking at 37°C for 8 hours and remained clear for up to 48 hours. In comparison, pamoate showed solubility in PBS solution (approximately 7.8 mg / mL, mean) for up to 48 hours at 37°C. Furthermore, a gel was observed at the bottom after shaking for 8 hours. These results indicate that pamoate showed significantly lower solubility than atosiban acetate in PBS.

[0089] Part B: Spray drying of atsiban pamoate The gelation of atosiban pamoate has been observed in specific solvent systems typically used in spray-drying processes, indicating that atosiban pamoate would likely be unsuitable for spray-drying. The inventors conducted further research to identify suitable solvents for providing a loading solution for the spray-drying stage.

[0090] B1: Initial Solubility Test The approximate solubility of atosiban pamoate was determined at room temperature and atmospheric pressure.

[0091] The following procedure was used to perform a visual inspection solubility screening method for determining approximate solubility: 1. Approximately 2 mg of atosiban-pamoate powder was weighed into each of the 2 mL vials; 2. For each group, the test solvent was added sequentially according to the following steps: Step 1: 50 μL of solvent was added to the vial. If the salt dissolved, the solubility data was calculated as (S) > 40 mg / mL (actual S was sometimes calculated via the formula: S = actual weight / 0.05); if the salt did not dissolve, the tester proceeded to Step 2; Step 2: 50 μL of solvent was added to the vial. If the salt dissolved, the solubility data was calculated as 40 > S > 20 mg / mL (actual S was calculated individually); if the salt did not dissolve, the tester proceeded to Step 3; Step 3: 100 μL of solvent was added to the vial. If the salt dissolved, the solubility data was calculated as 20 > S > 10 mg / mL (actual S was calculated individually); if the salt did not dissolve, the tester proceeded to Step 4; Step 4: 200 μL of solvent was added to the vial. If the salt dissolved, the solubility data was calculated as 10 > S > 5 mg / mL (actual S was calculated individually); if the salt did not dissolve, the tester proceeded to Step 5; Step 5: 200 μl of solvent was added to the vial. If the salt dissolved, the solubility data was calculated as 5 > S > 3.33 mg / mL (actual S was calculated individually); if the salt did not dissolve, the tester continued to Step 6; Step 6: 400 μl of solvent was added to the vial. If the salt dissolved, the solubility data was calculated as 3.33 > S > 2 mg / mL (actual S was calculated individually); if the salt did not dissolve, it was calculated as S < 2 mg / mL (actual S should be calculated individually).

[0092] The results of the initial solubility tests in pure volatile solvents are summarized in Table 2 below.

[0093] [Table 4]

[0094] The solubility of atosiban pamoate was observed to be limited in almost all pure volatile solvents (except methanol) tested. As a result, the inventors conducted several further studies on the solubility of atosiban pamoate in various mixed solvents of water and organic solvents. The results are shown in Table 3 below.

[0095] [Table 5]

[0096] These initial solubility studies revealed several possible solvent systems that provide good and / or acceptable levels of solubility for atosiban pamoate.

[0097] B2: Short-term stability test Next, the inventors conducted further studies on the short-term stability of atosiban pamoate to confirm its compatibility with various solvent systems. Stability tests were performed at 25°C and atmospheric pressure. The purity of atosiban pamoate was determined using UPLC at various time points (0 minutes, 4 hours, 24 hours, and 4 days) after adding it to the solvent system. To evaluate the short-term stability of atosiban pamoate, the change in the peak area ratio of free atosiban base (atosiban purity) at various time points was summarized. (The UPLC measurement method used in this test is summarized in the "Materials and Methods" section).

[0098] The results are shown in Table 4.

[0099] [Table 6]

[0100] Short-term stability data revealed that THF and acetone can lead to the degradation of the atosiban peptide under certain conditions, while acetonitrile, MeOH, and EtOH exhibit good compatibility with atosiban pamoate and are suitable for use in the spray-drying process.

[0101] B3: Development of spray drying process: Following initial studies of suitable solvents for use in loading solutions, further parameters of the spray drying process, including solvent, inlet temperature, and feed rate, were investigated. Spray gas flow rate (40 mm) and drying gas flow rate (35 mm). 3 The volumetric flow rate ( / h) was kept constant during process development. Note that 40 mm represents the height reading on the gas flow meter for the spray gas flow velocity. This number can be converted to the actual spray gas volumetric flow velocity under standard temperature and pressure conditions. For example, a height of 40 mm corresponds to an actual gas volumetric flow velocity of 667 L / h.

[0102] Next, several attributes of the spray-dried product, including purity, assayability, and needle passability, were analyzed.

[0103] In particular, a 300 mg scale spray-drying manufacturing process was carried out in six batches. The results are shown in Table 5 below.

[0104] [Table 7]

[0105] In Table 5, purity is based on the change in the peak area ratio of atosiban free base (as determined by ULC analysis), which indicates the degree of degradation of atosiban free base in atosiban pamoate. For example, a purity of approximately 100% indicates virtually no degradation of atosiban free base in atosiban pamoate, suggesting good stability during processing. In Table 5, the % assay data shows the content of atosiban free base in atosiban pamoate powder. The % assay of the final atosiban pamoate particles is approximately 80% due to the presence of pamoic acid in atosiban pamoate.

[0106] B4: Spray-dried atsiban pamoate particles B4.1: Method: Pamoic acid atosiban particles were prepared using the spray drying method. 1.2 g of freeze-dried pamoic acid atosiban powder was dissolved in a mixed solvent of MeOH / H2O (40 mL, 5:1, v / v). The solution was filtered through a 0.22 μm filter and spray-dried using a Mini Spray Dryer B-290 (Buchi, Switzerland) at an inlet temperature of 100°C and a feed rate of 4.0 mL / min. The spray gas flow rate and drying gas flow rate were set to 40 mm and 35 m, respectively. 3 Maintained at / h

[0107] B4.2: Analysis: Spray-dried pamoic acid atsiban particles, prepared according to the method outlined in B4:1, were characterized by ultra-high-performance liquid chromatography (UPLC) and scanning electron microscopy (SEM) (according to the methods outlined in the "Materials and Methods" section). The results are shown in Figures 4, 5, and 6.

[0108] See Figure 4, which shows the UPLC analysis of atosiban acetate (upper curve) and spray-dried atosiban pamoate particles (lower curve). The UPLC analysis showed that the purity of the spray-dried atosiban pamoate powder was nearly 100%. (Note that in the UPLC curve for atosiban pamoate, the peak at approximately 2.6 min is for atosiban free base, while the peak at approximately 6.6 min is for pamoic acid. In contrast, in the curve for atosiban acetate, since acetic acid does not produce a peak under the experimental conditions, only the atosiban free base peak is present at approximately 2.6 min.)

[0109] SEM analysis of spray-dried atosiban pamoate particles (prepared according to the procedure outlined in "B4.1: Method" above) showed that these particles had a spherical or nearly spherical shape with a diameter of approximately 1–8 μm (see SEM image in Figure 6). Such particles are considered suitable for use in injectable formulations. In contrast, SEM analysis of lyophilized atosiban pamoate powder showed that the particles generally had a larger particle size (ranging from 20 μm to 80 μm in diameter) and an irregular sheet shape (see SEM image in Figure 5). These were considered less suitable for use in injectable formulations.

[0110] For the purpose of clarifying understanding, this disclosure has been described in some detail by examples and embodiments, but such descriptions and embodiments should not be construed as limiting the scope of this disclosure. All disclosures of patent and scientific documents cited herein are expressly incorporated herein in their entirety by reference.

Claims

1. A method for preparing atosiban pamoate, (i) Contact and / or react together the first atosiban salt and the inorganic pamoate in the reaction mixture. Includes, A method by which the atosiban pamoate is formed as a precipitate.

2. The method according to claim 1, wherein the first atosiban salt is an atosiban salt having a solubility of at least 10 mg / mL in an aqueous solution at 25°C, and / or the first atosiban salt is selected from atosiban acetate, atosiban hydrochloride, and atosiban trifluoroacetate.

3. The method according to claim 1 or 2, wherein the inorganic pamoate is a metal pamoate optionally selected from sodium pamoate and potassium pamoate.

4. The method according to any one of claims 1 to 3, wherein the reaction mixture is an aqueous solution, optionally water, or an aqueous buffer solution.

5. (i) To provide a solution of the first atosiban salt, (ii) Contacting the solution of the first atosiban salt with the inorganic pamoate, It further includes, optionally, (iii) The method according to any one of claims 1 to 4, further comprising adding the inorganic pamoate to the solution of the first atosiban salt, and optionally further comprising adding the solution of the inorganic pamoate to the solution of the atosiban salt.

6. The method according to any one of claims 1 to 5, wherein the molar ratio of the atosiban salt to the inorganic pamoic acid used, in contact with, and / or reacted together is one of the following molar ratios: about 10:1 to about 1:10, about 5:1 to about 1:5, or about 3:1 to about 1:

3.

7. The further method comprises separating and / or removing the precipitate of atsiban pamoate; and optionally (i) freeze-drying the precipitate of pamoate atosiban to form freeze-dried pamoate atosiban); and / or (ii) To provide spray-dried atosiban pamoate particles by spray-drying atosiban pamoate. The method according to any one of claims 1 to 6, including

8. A method for providing pamoate atsiban particles, (i) To provide a loading solution of pamoate atsiban; (ii) spray-drying the loading solution to form the pamoic acid atsiban particles, A method wherein, optionally, the atosiban pamoate has a solubility of at least about 15 mg / mL, at least about 20 mg / mL, or at least about 25 mg / mL in the loading solution.

9. If the atosiban pamoate is stored for at least 1 hour, at least 2 hours, at least 3 hours, at least 4 hours, at least 12 hours, at least 24 hours, at least 36 hours, or at least 48 hours, it will be substantially stable in the loading solution and / or show minimal or no degradation; The method according to claim 8, wherein, optionally, when the atosiban pamoate is stored in the loading solution, it maintains at least about 98.9%, at least about 99.0%, at least about 99.1%, at least about 99.2%, at least about 99.3%, at least about 99.4%, or at least about 99.5% of the original level of purity.

10. The aforementioned loading solution (a) Having a boiling point of about 150°C or less, about 125°C or less, or about 100°C or less; and / or (b) comprising one or more solvents, wherein the one or more solvents are optionally selected from alcohol, water and acetonitrile; and / or (c) (i) Alcohol (for example, methanol, etc.) １ ~C ４ (ii) alcohol (for example, methanol, etc.) １ ~C ４ (Alcohol) and water; and (iii) a solvent system selected from acetonitrile and water, The method according to claim 8 or 9.

11. The aforementioned loading solution (i) an alcohol in a ratio of approximately 5:1 (for example, methanol or C １ ~C ４ Alcohol): Water (v / v); and (ii) Acetonitrile:Water in a ratio of approximately 3:1 (v / v) The method according to any one of claims 8 to 10, comprising a solvent system selected from the following.

12. Pamoate atosiban and (i) an alcohol in a ratio of approximately 5:1 (for example, methanol or C １ ~C ４ Alcohol): Water (v / v); and (ii) Acetonitrile:Water in a ratio of approximately 3:1 (v / v) A loading solution for a spray-drying process, comprising a solvent system selected from the above.

13. Spray-dried atosiban pamoate particles obtained or obtainable by the method of any one of claims 8 to 11, wherein the particles optionally include diameters of about 0.1 μm to about 50 μm (microns), about 0.5 μm to about 25 μm, or about 1 μm to about 10 μm.

14. It is atociban pamoate, (i) The molar ratio of atosiban to pamoic acid in the salt is about 2:1; and / or (ii ) an atosibampa salt that can be obtained or obtained by the method described in any one of claims 1 to 7.

15. A pharmaceutical composition comprising atosiban pamoate obtained or obtainable by the method described in any one of claims 1 to 7, spray-dried atosiban pamoate particles according to claim 13, or atosiban pamoate according to claim 14.

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