Sterile in-situ gel manufacturing method based on solvent removal technology and its products

Abstract

This paper describes a method for producing a sterile in-situ gel based on solvent removal technology, and the resulting product. Compared to conventional aseptic manufacturing methods for in-situ gel formulations, this method adds a volatile solvent during production to reduce the viscosity of the formulation solution, facilitating filtration and sterilization. The volatile solvent can then be removed by various methods without adversely affecting the final in-situ gel formulation. Research data shows that the volatile solvent residues in in-situ gel formulations produced using this method meet safety standards. Compared to formulations produced using the conventional radiation sterilization method, the types and amounts of degradation impurities in the polymer and active pharmaceutical ingredients are both reduced, further improving the safety of the formulation.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from a patent application for invention filed with the China Patent Office on January 10, 2023, bearing application number 202310035221.1 and entitled "Method for producing sterile in-situ gel based on solvent removal technology and product thereof," the entire contents of which are incorporated herein by reference.

[0002] The present disclosure is in the field of pharmaceutical formulations, and in particular relates to a method for producing a sterile in-situ gel based on a solvent removal technique, and the sterile in-situ gel produced by this method. [Background technology]

[0003] In situ forming implants (ISFIs) are novel drug delivery systems composed of biodegradable polymer solutions or semisolids that solidify / gel at the site of delivery to form a depot. Depending on the formulation, ISFIs are primarily formed by various mechanisms, including in situ precipitation, organogelation, and polymer crosslinking. Among these, the Atrigel® system, based on in situ precipitation by solvent diffusion, is currently the most widely used and commercially available technology. Several commercial products have been released and are widely used in the treatment of periodontal disease (Atridox®), advanced prostate cancer (Eligard®), opioid use disorder (Subloade®), and schizophrenia (Perseris®).

[0004] Dunn et al. first proposed the concept of Atrigel® technology in 1987. The carrier system is typically formed by mixing a biodegradable polymer carrier (e.g., poly(lactic-co-glycolic) (PLGA) or polylactic acid (PLA)) with an organic solvent (e.g., N-methylpyrrolidone (NMP)). Small molecules, polypeptides, and macromolecular drugs are then dissolved or dispersed to form a solution or suspension suitable for in vivo delivery. These in-situ gel formulations cannot be terminally sterilized by dry or moist heat because the polymer carrier (e.g., PLGA) and active pharmaceutical ingredients are prone to decomposition and potential interactions occur between them under prolonged, high-temperature conditions. Furthermore, the high polymer concentration and gel viscosity make it difficult to meet the sterility requirements for incorporation into biopharmaceuticals by filtration. Therefore, internationally, these in-situ gel formulations are typically sterilized by irradiation, primarily gamma irradiation.

[0005] The principle of radiation sterilization is the emission of high-energy rays by atoms transitioning from a high-energy state to a low-energy state. These rays have high energy and strong penetrating power, causing a series of biophysical and biochemical reactions in microorganisms in pharmaceuticals, inhibiting and destroying their metabolism and growth. However, they also promote the degradation of the polymer carrier and active pharmaceutical ingredient in the in-situ gel, as well as interactions between the polymer and drug, resulting in the production of several undesirable impurities. Therefore, such formulations typically require the carrier and drug components to be packaged separately and prepared before use, which can lead to problems with improper preparation or use and inaccurate dosing during use. Furthermore, because radiation-related factories require strict qualification screening and site selection, pharmaceutical manufacturers typically outsource the radiation sterilization process to specialized irradiation factories. However, all steps from product packaging to transportation and irradiation are completed outside of GMP or cGMP systems, increasing risks to control and quality assurance.

[0006] Therefore, it is of great significance to develop a simple and sterile manufacturing method for in-situ gel formulations. Summary of the Invention [Problem to be solved by the invention]

[0007] In consideration of the problems present in the prior art, such as the accelerated decomposition of drugs and polymeric carriers, the generation of additional impurities, and inconvenience in use in conventional aseptic production methods for in-situ gel formulations, the present disclosure provides a method for producing an in-situ gel formulation by adding a volatile solvent during the production of the conventional in-situ gel formulation to reduce the viscosity of the gel solution, which can facilitate filtration and sterilization, and by subsequently removing the volatile solvent, thereby solving the problems present in conventional aseptic production methods for in-situ gel formulations. [Means for solving the problem]

[0008] A first aspect of the present disclosure provides a method for producing an in-situ gel formulation, comprising the steps of: i: a step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials, and, if desired, some or all of the remaining components in the production raw materials, to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. Furthermore, when the raw material solution I does not contain all of the raw materials, the production method further includes the following steps. iv: A step of uniformly mixing the product obtained in step iii with manufacturing raw materials not contained in the sterile raw material solution I under sterile conditions. The manufacturing material further comprises an active pharmaceutical ingredient, a non-volatile solvent, and optionally a release-modifying agent. Furthermore, if the raw material solution I does not contain all of the production raw materials, in step iv, the raw material solution obtained in step iii and the production raw materials not contained in the raw material solution I are uniformly mixed by one or more of the methods shown in (a) to (g) below. (a) adding the sterile active pharmaceutical ingredient via a sterile delivery device; (b) filtering and sterilizing a solution of the active pharmaceutical ingredient and the non-volatile solvent before adding it; (c) if present, filtering and sterilizing a solution of said active pharmaceutical ingredient and said release-modifying agent before adding it; (d) adding, if present, a solution of said active pharmaceutical ingredient, said non-volatile solvent, and said release-modifying agent after sterilization by filtration; (e) adding the non-volatile solvent after filtering and sterilizing it; (f) if present, filtering and sterilizing the solution of said non-volatile solvent and said release-modifying agent before adding; (g) If present, the release-modifying agent is sterile filtered before addition. Preferably, when the raw material solution I does not contain all of the production raw materials, the raw material solution I satisfies any one of the following conditions (j) to (p). (j) the raw material solution I contains the active pharmaceutical ingredient and the non-volatile solvent, but does not contain the release-modifying agent; (k) the raw material solution I contains the active pharmaceutical ingredient and the release-modifying agent, but does not contain the non-volatile solvent; (l) the raw material solution I contains the active pharmaceutical ingredient and does not contain the non-volatile solvent or the release-modifying agent; (m) the raw material solution I contains the non-volatile solvent and the release-modifying agent, but does not contain the active pharmaceutical ingredient; (n) the raw material solution I contains the non-volatile solvent and does not contain the active pharmaceutical ingredient and the release-modifying agent; (o) the raw material solution I contains the release-modifying agent, but does not contain the active pharmaceutical ingredient or the non-volatile solvent; (p) The raw material solution I does not contain the active pharmaceutical ingredient, the non-volatile solvent, or the release-modifying agent. Furthermore, the volatile solvent is selected from a volatile alkane, a volatile halogenated alkane, a volatile alcohol, a volatile ketone, a volatile ester, a volatile organic cyanide or a volatile ether. Preferably, the mass ratio of the volatile solvent to the biodegradable polymer in the production raw material is 10:1 to 1:1. Furthermore, the volatile solvent is selected from dichloromethane, chloroform, or acetone. Furthermore, in the step iii, the method for removing the volatile solvent from the sterile raw material liquid I is at least one method selected from the group consisting of reducing pressure, temperature control, aeration, and stirring. Furthermore, the biodegradable polymer is selected from polyesters, polyester copolymers or block copolymers. Further, the biodegradable polymer is selected from PLGA, PLA, PCL, POE, PEG-PLA, PLA-PEG-PLA, PEG-PLGA, PEG-PLGA-PEG, TPGS-PLGA, or TEG-POE. Furthermore, the non-volatile solvent is N-methylpyrrolidone and / or dimethyl sulfoxide. Additionally, the optional release modifier is one or more selected from ethyl acetate, medium chain triglycerides, glyceryl triacetate, glyceryl tricaprylate, benzyl benzoate, and benzyl alcohol. Preferably, the optional release modifier is benzyl benzoate and / or glyceryl triacetate.

[0009] A second aspect of the present disclosure provides an in-situ gel formulation produced by the production method described in the first aspect of the present disclosure. [Effects of the Invention]

[0010] Compared to conventional aseptic manufacturing methods for in-situ gel formulations, the present disclosure provides a manufacturing method for an in-situ gel in which the viscosity of the formulation solution is reduced by adding a volatile solvent during manufacturing, which can facilitate filtration and sterilization, and the volatile solvent in the formulation can then be removed by various methods without adversely affecting the final in-situ gel formulation.

[0011] Research data shows that the volatile solvent residues in the in-situ gel formulations produced by the manufacturing method of the present disclosure meet safety standards, and the types and contents of decomposition impurities in the polymer and active pharmaceutical ingredients are both reduced compared to formulations produced by the traditional manufacturing method of radiation sterilization, further improving the safety of the formulations.

[0012] Furthermore, the sterile in-situ gel formulation produced by the manufacturing method of the present disclosure contains an active pharmaceutical ingredient, and solves the problems of inconvenience in use and inaccurate dosage caused by the separate packaging of the carrier portion and the active pharmaceutical ingredient present in the prior art, thereby significantly improving the convenience and accuracy of use of the formulation.

[0013] Furthermore, the method for producing an in-situ gel formulation according to the present disclosure is simple to operate, allows pharmaceutical manufacturing plants to independently produce sterile pharmaceuticals while ensuring product quality, and is advantageous for managing the manufacturing process and ensuring quality. Furthermore, the method for producing an in-situ gel formulation according to the present disclosure has low requirements for the sterile quality of raw materials and for the space and equipment required for sterile supply, thereby enabling cost reduction. [Brief explanation of the drawings]

[0014] [Figure 1] 1 shows the in vivo drug concentration time course curves in rats for the rotigotine in-situ gel formulations of Examples 1 and 4. DETAILED DESCRIPTION OF THE INVENTION

[0015] Although embodiments of the present disclosure will be described below, the present disclosure is not limited to these. The present disclosure is not limited to the configurations described below, and various modifications are possible within the scope of the claims. Embodiments and examples obtained by appropriately combining the technical means disclosed are also included in the technical scope of the present disclosure.

[0016] <Definition> In the present disclosure, a numerical range expressed as "numeric value A to numerical value B" or "numeric value A minus numerical value B" means a range including the limit values ​​A and B. In the present disclosure, when "may" is used, it includes both cases where some processing is performed and cases where some processing is not performed. In this disclosure, "optionally" or "desirably" means that the event or circumstance described below may or may not occur, and the description includes both cases where the event occurs and cases where it does not occur. In this disclosure, the terms "a" or "an" or "the" can refer to "one," but can also refer to "one or more," "at least one," and "one or more." In this disclosure, the term "about" means that a numerical value includes the standard deviation of error for the device or method being used to measure that value. All numerical ranges and parameters used to define this disclosure are approximations, but have reproduced the numerical values ​​of specific examples as accurately as possible. However, any numerical value inherently includes the standard deviation of the measurement device or method. Therefore, unless otherwise specified, all ranges, amounts, values, and percentages used in this disclosure should be understood to be modified by "about." Here, "about" typically means that the actual numerical value is within ±10%, ±5%, ±1%, or ±0.5% of a particular numerical value or range.

[0017] In this disclosure, parameters related to PLGA are explained as follows. Taking PLGA (7525 DLG 2A) as an example, "7525" means that the molar ratio of lactide to glycolide is 75:25, "DLG" means lactide / glycolide copolymer, and "DL" means polylactide. "2" represents the intrinsic viscosity, 1 means that the intrinsic viscosity is 0.05-0.15 dL / g, 1.5 means that the intrinsic viscosity is 0.10-0.20 dL / g, 2 means that the intrinsic viscosity is 0.15-0.25 dL / g, 2.5 means that the intrinsic viscosity is 0.20-0.30 dL / g, 3 means that the intrinsic viscosity is 0.25-0.35 dL / g, 3.5 means that the intrinsic viscosity is 0.30-0.40 dL / g, and 4 ....5 means that the intrinsic viscosity is 0.20-0.30 d "Intrinsic viscosity" means 0.35-0.45 dL / g, "4.5" means 0.40-0.50 dL / g, "5" means 0.45-0.55 dL / g, "6" means 0.50-0.70 dL / g, "7" means 0.60-0.80 dL / g, "8" means 0.70-0.90 dL / g, and "9" means 0.80-1.00 dL / g. The intrinsic viscosity corresponding to a PLGA with a molecular weight of 100,000 Da is 1 dL / g. "A" indicates that the terminal group is acid, and "E" indicates that the terminal group is ester.

[0018] In this disclosure, the term "water" includes any water usable in the art, such as deionized water, distilled water, ion-exchanged water, secondary distilled water, highly purified water, and purified water. In the present disclosure, the term "room temperature" refers to 25±2°C. In the present disclosure, the term "normal pressure" refers to one standard atmospheric pressure.

[0019] Moreover, unless otherwise defined, other technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0020] The present disclosure was mainly completed based on the following findings. In order to develop a simple method for manufacturing a sterile in-situ gel, as a result of intensive studies by the inventors of the present disclosure, in the conventional in-situ gel manufacturing process, a volatile solvent (such as chloroform, dichloromethane, acetone, etc.) is added to reduce the viscosity of the gel solution, and then, after filtering and sterilizing with a 0.22 μm filter membrane, the volatile solvent is removed, and finally, it is filled in a sterile environment, and a method for manufacturing a sterile in-situ gel based on a solvent removal technique is provided.

[0021] The present invention will be described in more detail below.

[0022] <Method for manufacturing an in-situ gel preparation> The present disclosure provides a method for manufacturing an in-situ gel preparation including the following steps. i: A step of uniformly mixing a biodegradable polymer and a volatile solvent in the manufacturing raw materials, and optionally a part or all of the components in the remaining manufacturing raw materials to obtain a raw material liquid I; ii: A step of filtering and sterilizing the raw material liquid I to obtain a sterile raw material liquid I; iii: A step of removing the volatile solvent from the sterile raw material liquid I. When the raw material liquid I does not contain all the manufacturing raw materials, the manufacturing method further includes the following steps. iv: A step of uniformly mixing the product obtained in step iii and the sterile manufacturing raw materials not contained in the raw material liquid I under sterile conditions. The manufacturing raw materials further include a pharmaceutical active ingredient, a non-volatile solvent, and an optionally present release regulator.

[0023] [Manufacturing raw materials for an in-situ gel preparation] The manufacturing raw materials according to the present disclosure include a volatile solvent, a biodegradable polymer, a non-volatile solvent, a pharmaceutical active ingredient, and an optionally present release regulator. In some embodiments, the manufacturing raw materials according to the present disclosure include a volatile solvent, a biodegradable polymer, a non-volatile solvent, and a pharmaceutical active ingredient. In another embodiment, the manufacturing materials of the present disclosure include a volatile solvent, a biodegradable polymer, a non-volatile solvent, an active pharmaceutical ingredient, and a release-modifying agent.

[0024] Volatile solvents In the present disclosure, the term "volatile solvent" refers to a liquid substance that is volatile at room temperature and normal pressure. The present disclosure does not limit the specific type of volatile solvent, and it can be determined by those skilled in the art according to actual needs.

[0025] In some embodiments, the volatile solvent according to the present disclosure is selected from volatile halogenated alkanes, volatile alcohols, volatile ketones, or volatile ethers. Suitable volatile alkanes include, but are not limited to, pentane, cyclopentane, cyclohexane, n-hexane, n-octane, isooctane, and heptane. Suitable volatile halogenated alkanes include, but are not limited to, dichloromethane, chloroform, and carbon tetrachloride. Suitable volatile alcohols include, but are not limited to, methanol, ethanol, propanol, and butanol. Suitable volatile ketones include, but are not limited to, acetone and cyclohexanone. Suitable volatile esters include, but are not limited to, ethyl acetate. Suitable volatile organic cyanides include, but are not limited to, acetonitrile. Suitable volatile ethers include, but are not limited to, diethyl ether.

[0026] In some embodiments, the boiling point of the volatile solvents according to the present disclosure is less than 150°C, preferably less than 100°C, and more preferably less than 70°C.

[0027] In some specific embodiments, the volatile solvent of the present disclosure is selected from dichloromethane, chloroform, or acetone. The boiling points of these three volatile solvents are low: dichloromethane (about 39°C), chloroform (about 61°C), and acetone (about 53°C). These low boiling points are significantly different from the boiling point of N-methylpyrrolidone, the nonvolatile solvent in the formulation (about 202-204°C). These low boiling points are advantageous for removing the volatile solvent without volatilizing the nonvolatile solvent. Furthermore, all three volatile solvents can effectively dissolve biodegradable polymers (e.g., PLGA), effectively reducing the viscosity of the biodegradable polymer and facilitating filtration and sterilization.

[0028] In the present disclosure, there are no particular limitations on the amount of volatile solvent used, but those skilled in the art can adjust the amount according to the actual production conditions as long as the viscosity of the solution containing the biodegradable polymer can be reduced to a level that enables filtration and sterilization.

[0029] In some embodiments, the mass ratio of the volatile solvent to the biodegradable polymer used in the present disclosure is 10:1 to 1:1, preferably 5:1 to 1:1, such as 5:1, 4:1, 3:1, 2:1, 1:1, or any value within the range. The amount of volatile solvent used within the above range not only satisfies the requirement for reducing the viscosity of the solution, but is also advantageous for subsequent removal of the volatile solvent.

[0030] biodegradable polymers In the present disclosure, the terms "biodegradable polymer," "bioabsorbable polymer," and "absorbable polymer" are used interchangeably and refer to a polymer that degrades by chemical or physical methods when interacting with a physiological environment, and erodes, degrades, or dissolves over a period of time, such as days, weeks, or months, at an implantation site within a subject. Biodegradable polymers serve a temporary role in a subject, such as delivering a bioactive agent such as a drug. Biodegradable polymers can be broken down into fragments that can be metabolized or excreted by the host. In the present disclosure, the specific type of biodegradable polymer is not particularly limited, and can be determined by one of ordinary skill in the art based on actual needs.

[0031] In some embodiments, the biodegradable polymer according to the present disclosure is selected from polyesters or polyester copolymers. Polyester refers to a polymer in which all or substantially all of the repeating units are linked via ester groups. Polyesters can be formed by reacting monomers having carboxyl and hydroxyl groups to form ester groups. Suitable polyesters include, but are not limited to, polyglycolides, polylactides, polycaprolactones, polyorthoesters, and the like. Suitable polyester copolymers include, but are not limited to, lactide / glycolide copolymers, ε-caprolactone / glycolide copolymers, lactide / trimethylene carbonate copolymers, lactide / glycolide / caprolactone terpolymers, lactide / glycolide / trimethylene carbonate terpolymers, lactide / caprolactone / trimethylene carbonate terpolymers, glycolide / caprolactone / trimethylene carbonate terpolymers, and lactide / glycolide / caprolactone / trimethylene carbonate tetrapolymers. In other embodiments, the biodegradable polymers of the present disclosure may be selected from block copolymers, such as PLGA and / or PLA-based block copolymers, such as PEG-PLA, PLA-PEG-PLA, PEG-PLGA, PEG-PLGA-PEG, and TPGS-PLGA, or polyorthoester-based block copolymers, such as TEG-POE.

[0032] In some specific embodiments, the biodegradable polymer according to the present disclosure is selected from lactide / glycolide copolymer, polycaprolactone, or polyorthoester.

[0033] In some more specific embodiments, the biodegradable polymer according to the present disclosure is a lactide / glycolide copolymer. In the present disclosure, the molar ratio of lactide to glycolide in the lactide / glycolide copolymer is not particularly limited, but can be determined by those skilled in the art according to actual needs. For example, the molar ratio of lactide to glycolide in the lactide / glycolide copolymer may be 50:50-95:5, such as 50:50, 75:25, 85:15, or 95:5.

[0034] The present disclosure is not particularly limited to the molecular weight of the biodegradable polymer, but a person skilled in the art can determine this based on actual needs. For example, the molecular weight of the biodegradable polymer according to the present invention may be 5,000 to 70,000 Da, such as 5,000 Da, 10,000 Da, 15,000 Da, 20,000 Da, 25,000 Da, 30,000 Da, 35,000 Da, 40,000 Da, 45,000 Da, 50,000 Da, 55,000 Da, 60,000 Da, 65,000 Da, 70,000 Da, or any value within the above range.

[0035] Non-volatile solvents In the present disclosure, a "non-volatile solvent" refers to a solvent that is not volatile at normal temperature and pressure, that diffuses in a living body, and that can be metabolized or absorbed by a living body. In the present disclosure, the specific type of non-volatile solvent is not particularly limited, and can be determined by a person skilled in the art according to actual needs.

[0036] In some embodiments, the non-volatile solvent according to the present disclosure is N-methylpyrrolidone and / or dimethyl sulfoxide. In some specific embodiments, the non-volatile solvent according to the present disclosure is N-methylpyrrolidone.

[0037] Release Modifiers In the present disclosure, the "release modifier" is used to adjust the release rate of the active pharmaceutical ingredient in the in-situ gel formulation over time in vivo and in vitro. The present disclosure does not limit the specific type of the release modifier, which can be determined by those skilled in the art according to actual needs.

[0038] In some embodiments, the release-modifying agent according to the present disclosure is one or more selected from ethyl acetate, medium chain triglycerides, glyceryl triacetate, glyceryl tricaprylate, benzyl benzoate, and benzyl alcohol.

[0039] In some specific embodiments, the release-modifying agent according to the present disclosure is benzyl benzoate and / or glyceryl triacetate. In some more specific embodiments, the release-modifying agent according to the present disclosure is benzyl benzoate.

[0040] Active Pharmaceutical Ingredients In the present disclosure, the specific type of active pharmaceutical ingredient in the in-situ gel formulation is not particularly limited, and can be selected by those skilled in the art according to actual needs. In some embodiments, the active pharmaceutical ingredient according to the present disclosure is a poorly soluble drug. In some embodiments, the active pharmaceutical ingredient according to the present disclosure is rotigotine or pramipexole hydrochloride.

[0041] [In situ gel manufacturing method] The method for producing an in-situ gel according to the present disclosure is based on a solvent removal technique, in which the addition of a volatile solvent during production reduces the viscosity of the solution containing the biodegradable polymer, allowing sterilization by filtration. The volatile properties of the volatile solvent can be utilized to remove the volatile solvent from the formulation, improving the convenience of producing a sterile in-situ gel formulation.

[0042] In some embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the raw materials with all of the remaining components in the raw materials to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I.

[0043] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw material with the active pharmaceutical ingredient, non-volatile solvent, and optionally the release-modifying agent to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I.

[0044] In the above-mentioned embodiment, all raw materials can be sterilized by filtration in one go, which greatly improves the convenience of pharmaceutical manufacturing. Moreover, experimental data has demonstrated that the above-mentioned embodiment does not adversely affect the active pharmaceutical ingredient or its pharmacokinetic behavior, and significantly reduces the types and amounts of impurities generated during the manufacturing process compared to radiation sterilization methods.

[0045] In another embodiment, a method for preparing an in-situ gel formulation according to the present disclosure comprises the following steps: i: a step of uniformly mixing the biodegradable polymer and the volatile solvent in the production raw materials, and, if desired, a portion of the remaining components in the production raw materials, to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii) removing the volatile solvent from the sterile raw material solution I; iv: A step of uniformly mixing the product obtained in step iii with the raw materials not contained in the sterile raw material solution I under sterile conditions.

[0046] In some specific embodiments, when the raw material solution I does not contain all of the production raw materials, the raw material solution I satisfies any one of the following conditions (j) to (p). (j) said raw material solution I comprises said active pharmaceutical ingredient and said non-volatile solvent, but does not comprise said optional release-modifying agent; (k) the raw material solution I contains the active pharmaceutical ingredient and the release-modifying agent, but does not contain the non-volatile solvent; (l) the raw material solution I contains the active pharmaceutical ingredient and does not contain the non-volatile solvent or the release-modifying agent; (m) the raw material solution I contains the non-volatile solvent and the release-modifying agent, but does not contain the active pharmaceutical ingredient; (n) the raw material solution I contains the non-volatile solvent and does not contain the active pharmaceutical ingredient and the release-modifying agent; (o) the raw material solution I contains the release-modifying agent, but does not contain the active pharmaceutical ingredient or the non-volatile solvent; (p) The raw material solution I does not contain the active pharmaceutical ingredient, the non-volatile solvent, or the release-modifying agent.

[0047] In step iv, if all of the raw materials not contained in the raw material liquid I are solids, the sterile raw materials not contained in the raw material liquid I may be added to the material obtained in step iii using a device such as a sterile supply device and mixed uniformly. If all of the raw materials not contained in the raw material liquid I are liquid components, it is preferable to sterilize the raw materials not contained in the raw material liquid I by a filtration sterilization method, and then add the sterilized sterile components to the material obtained in step iii and mix uniformly. If the raw materials not contained in the raw material liquid I contain both solids and liquid components, the sterile solids may be added to the material obtained in step iii using a device such as a sterile supply device and mixed uniformly, or the liquid components may be sterilized by a filtration sterilization method, and the sterilized sterile liquid components may be added to the material obtained in step iii and mixed uniformly, or the solids and liquid components may be mixed uniformly, followed by filtration sterilization, and then the sterilized sterile components may be added to the material obtained in step iii and mixed uniformly.

[0048] In some preferred embodiments, when raw material solution I does not contain all of the raw materials, in step iv, the raw materials not contained in raw material solution I and the material obtained in step iii are uniformly mixed by one or more of the following methods (a) to (g): (a) adding the sterile active pharmaceutical ingredient via a sterile delivery device; (b) filtering and sterilizing a solution of the active pharmaceutical ingredient and the non-volatile solvent before adding it; (c) if present, filtering and sterilizing a solution of said active pharmaceutical ingredient and said release-modifying agent before adding it; (d) adding, if present, a solution of said active pharmaceutical ingredient, said non-volatile solvent, and said release-modifying agent after sterilization by filtration; (e) adding the non-volatile solvent after filtering and sterilizing it; (f) if present, filtering and sterilizing the solution of said non-volatile solvent and said release-modifying agent before adding; (g) If present, the release-modifying agent is sterile filtered before addition.

[0049] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with the active pharmaceutical ingredient and non-volatile solvent to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. If a release-modifying agent is present in the manufacturing material, the manufacturing method further comprises the following steps: iv: A step of homogeneously mixing the product obtained in step iii with the filter-sterilized release-modifying agent under aseptic conditions.

[0050] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with the active pharmaceutical ingredient and release-modifying agent to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. The manufacturing method further includes the following steps: iv: A step of uniformly mixing the product obtained in step iii with a non-volatile solvent that has been sterilized by filtration under aseptic conditions.

[0051] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with the active pharmaceutical ingredient to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. If no release-modifying agent is present in the manufacturing material, the manufacturing method further comprises the following steps: iv: A step of uniformly mixing the product obtained in step iii with a non-volatile solvent that has been sterilized by filtration under aseptic conditions.

[0052] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with the active pharmaceutical ingredient to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. If a release-modifying agent is present in the manufacturing material, the manufacturing method further comprises the following steps: iv) A step of uniformly mixing the non-volatile solvent and the release-modifying agent, filtering and sterilizing the mixture, and then uniformly mixing the mixture with the product obtained in step iii under aseptic conditions.

[0053] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with the non-volatile solvent and release-regulating agent to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. The manufacturing method further includes the following steps: iv: A step of adding a sterile active pharmaceutical ingredient to the material obtained in step iii using a sterile feeding device and mixing them uniformly.

[0054] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with the non-volatile solvent and release-regulating agent to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. The manufacturing method further includes the following steps: iv: A process of uniformly mixing the active pharmaceutical ingredient and a non-volatile solvent, filtering and sterilizing the mixture, and then uniformly mixing the mixture with the mixture obtained in step iii under aseptic conditions.

[0055] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: a step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with a non-volatile solvent to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. If no release-modifying agent is present in the manufacturing material, the manufacturing method further comprises the following steps: iv: A step of adding a sterile active pharmaceutical ingredient to the material obtained in step iii using a sterile feeding device and mixing them uniformly.

[0056] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: a step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with a non-volatile solvent to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. If a release-modifying agent is present in the manufacturing material, the manufacturing method further comprises the following steps: iv: A step of uniformly mixing the active pharmaceutical ingredient and the release modifier, filtering and sterilizing the mixture, and then uniformly mixing the mixture with the mixture obtained in step iii under aseptic conditions.

[0057] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials with the release-regulating agent to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. The manufacturing method further includes the following steps: iv: A process of uniformly mixing the active pharmaceutical ingredient and a non-volatile solvent, filtering and sterilizing the mixture, and then uniformly mixing the mixture with the mixture obtained in step iii under aseptic conditions.

[0058] In some specific embodiments, a method for producing an in-situ gel formulation according to the present disclosure comprises the following steps: i: A step of uniformly mixing the biodegradable polymer and the volatile solvent in the production raw materials to obtain a raw material solution I; ii: filtering and sterilizing the raw material solution I to obtain a sterile raw material solution I; iii: A step of removing the volatile solvent from the sterile raw material solution I. The manufacturing method further includes the following steps: iv) A step of homogeneously mixing the active pharmaceutical ingredient, the non-volatile solvent and the optionally present release modifier, followed by sterilization by filtration and homogeneously mixing under aseptic conditions with the product obtained in step iii.

[0059] For the filtration and sterilization step in the method for producing an in-situ gel formulation according to the present disclosure, it is preferable to use a micropore filtration membrane, and it is more preferable to use a 0.22 μm filtration membrane.

[0060] The method for removing the volatile solvent in the method for producing an in-situ gel formulation is not particularly limited in the present disclosure, but can be selected by those skilled in the art according to actual needs. In some embodiments, the method for removing the volatile solvent according to the present disclosure is one or more selected from the group consisting of reduced pressure, temperature control, aeration, and stirring. Furthermore, an appropriate device can be selected for removing the volatile solvent, for example, a thin film evaporator, a rotary evaporator, or a blower, etc., but is not limited thereto.

[0061] The steps included in the method for producing an in-situ gel formulation according to the present disclosure may be followed by a step of adding other ingredients, or may further include a step of filling, etc. Preferably, the other ingredients added are sterile, and preferably, the other ingredients added are non-active pharmaceutical ingredients. Example

[0062] In order to more clearly explain the present invention, the following examples are provided to further illustrate the present invention. However, these examples are merely a partial example of the present disclosure and are not intended to limit the present disclosure. Unless otherwise specified, the devices, reagents, materials, experimental animals, etc. used in the present disclosure can be obtained through conventional commercial means. Unless specific conditions are specified in the examples, they are assumed to have been carried out under conventional conditions or conditions recommended by the manufacturer.

[0063] Example 1 (Comparative Example) 33.75 g of PLGA (7525 DLG 2A), 28.9 g of NMP, 2.75 g of rotigotine, and 12.4 g of benzyl benzoate were precisely weighed, mixed, stirred, and dissolved uniformly, and dispensed into 1 mL prefilled syringes. The mixture was then sterilized by 25 kGy of gamma irradiation.

[0064] Example 2 33.75 g of PLGA (7525 DLG 2A), 28.9 g of NMP, 110 g of dichloromethane, 2.75 g of rotigotine, and 12.4 g of benzyl benzoate were precisely weighed, mixed, and dissolved. The solution was then sterilized by filtration through a 0.22 μm filter. The dichloromethane was then removed by rotary evaporation. The solution was then dispensed into 1 mL prefilled syringes in a sterile isolator.

[0065] Example 3 33.75 g of PLGA (7525 DLG 2A), 28.9 g of NMP, 110 g of chloroform, 2.75 g of rotigotine, and 12.4 g of benzyl benzoate were precisely weighed, mixed, and dissolved. The solution was then sterilized by filtration through a 0.22 μm filter. The chloroform was then removed by rotary evaporation. The solution was then dispensed into 1 mL prefilled syringes in a sterile isolator.

[0066] Example 4 33.75 g of PLGA (7525 DLG 2A), 28.9 g of NMP, 110 g of acetone, 2.75 g of rotigotine, and 12.4 g of benzyl benzoate were precisely weighed, mixed, and dissolved. The solution was then sterilized by filtration through a 0.22 μm filter. The acetone was then removed by rotary evaporation. The solution was then dispensed into 1 mL prefilled syringes in a sterile isolator.

[0067] Example 5 67.5 g of PLGA (7525 DLG 2A), 57.8 g of NMP, 220 g of acetone, 5.5 g of rotigotine, and 24.8 g of benzyl benzoate were precisely weighed, mixed, and dissolved. The mixture was then sterilized by filtration using a 0.22 μm filter. The acetone was then removed using a thin-film evaporator at a rate of 15 mL / min at 40°C. The mixture was then dispensed into 1 mL prefilled syringes in a sterile isolator.

[0068] Example 6 33.75 g of PLGA (7525 DLG 2A), 110 g of acetone, 21.7 g of NMP, and 12.4 g of benzyl benzoate were precisely weighed, mixed, dissolved, and then filtered and sterilized through a 0.22 μm filter. The acetone was then removed by rotary evaporation to obtain raw material solution A. 7.2 g of NMP and 2.75 g of rotigotine were weighed, mixed, dissolved, and then filtered and sterilized through a 0.22 μm filter. The mixture was then homogeneously mixed with raw material solution A. The mixture was then dispensed into 1 mL prefilled syringes in a sterile isolator.

[0069] Example 7 (Comparative Example) 33.75 g of PLGA (5050 DLG 2E), 38.8 g of NMP, and 6.5 g of sterile pramipexole hydrochloride were precisely weighed and mixed until uniformly dispersed and mixed, then dispensed into a 1 mL prefilled syringe. Finally, the mixture was sterilized by 25 kGy of gamma irradiation.

[0070] Example 8 33.75 g of PLGA (5050 DLG 2E), 38.8 g of NMP, and 110 g of acetone were precisely weighed, mixed, dissolved, and then filtered through a 0.22 μm filter membrane. The acetone was then removed by rotary evaporation to obtain stock solution A. 6.5 g of sterile pramipexole hydrochloride was added to stock solution A using a sterile supply device (αβ valve) and stirred until uniformly dispersed and mixed. The mixture was then dispensed into 1 mL prefilled syringes in a sterile isolator.

[0071] Study results of the example Experimental Example 1: Examination of residual solvent Approximately 0.1 to 0.5 g of each sample from Examples 1 to 8 was precisely weighed and placed in a headspace bottle. 0.5 to 5 mL of dimethyl sulfoxide and water were precisely added, and the bottle was immediately sealed to obtain a test solution. The test solution and the control solution were measured by gas chromatography, and the amount of residual solvent was calculated from the peak area using the external standard method. Detailed results are shown in Table 1.

[0072] [Table 1]

[0073] The results in Table 1 show that the residual amounts of volatile solvents in the samples of Examples 2 to 6 and Example 8 all met the limit standards, and therefore met the safety requirements for the formulations.

[0074] Experimental Example 2: In vitro release of in-situ gel formulation (1) In vitro burst release study of rotigotine in-situ gel formulation A 21G needle (0.8 mm outer diameter) was connected to a 1 mL syringe, and approximately 0.1 mL was drawn and precisely measured. The sample was slowly injected dropwise into 50 mL of release medium (0.01 M phosphate buffer solution (0.2% SDS, adjusted to pH 7.40)). The syringe was then precisely weighed again, and the amount of injected sample was calculated using the weight loss method. The sample bottles were kept warm in a constant-temperature shaking water bath at 25 ± 0.5°C. Each sample was prepared in triplicate. 2 mL of supernatant was collected at predetermined time points and replenished with 2 mL of release medium at the same temperature. The test solution was measured by HPLC, and the cumulative release amount was calculated using the external standard method. Details of the in vitro release measurement results of rotigotine in Examples 1 to 6 are shown in Table 2. The in vitro release rate is the mass percentage of the released drug relative to the total active pharmaceutical ingredient in the formulation.

[0075] (2) In vitro release study of pramipexole in-situ gel formulation A 21G needle (0.8 mm outer diameter) was connected to a 1 mL syringe, and 0.1 mL was drawn up and precisely measured. The formulation was slowly injected into 100 mL of release medium (0.01 M phosphate buffer solution (0.2% SDS, adjusted to pH 7.40)), the syringe was precisely weighed again, and the injected sample volume was calculated using the weight loss method. The sample bottle was placed in a thermostatic shaking water bath at 37 ± 0.5°C and shaken at 50 rpm. Each sample was prepared in triplicate. 2 mL of supernatant was collected at predetermined time points and replenished with 2 mL of release medium at the same temperature. The test solution was measured by HPLC, and the cumulative release amount was calculated using the external standard method. Detailed results of the in vitro release measurement of pramipsole in Examples 7 and 8 are shown in Table 3.

[0076] [Table 2]

[0077] The results in Table 2 show that there was no significant difference in the in vitro release rate within 48 hours between Examples 2 to 6 and Example 1, indicating that the sterile rotigotine in-situ gel prepared by the solvent removal technique did not affect the release profile of the formulation.

[0078] [Table 3]

[0079] The results in Table 3 show that there was no significant difference in the in vitro release rate within 48 hours between Example 8 and Example 7, indicating that the sterile pramipexole in-situ gel prepared by the solvent removal technique did not affect the release characteristics of the formulation.

[0080] Experimental Example 3: Investigation of related substances in rotigotine in-situ gel formulations After leaving the sample at 2 to 8°C for 6 months under a light-protected condition, 180 mg of the sample was weighed and placed in a 2 mL volumetric flask, 0.4 mL of the impurity control stock solution was added, and the mixture was dissolved with a diluent and diluted to the graduated mark. After shaking well, the content of rotigotine related substances was measured by HPLC. The details of the measurement results of the related substance content for Examples 1 to 4 and Example 6 are shown in Table 4. The related substance content is the mass % of each related substance in the in situ gel formulation.

[0081] [Table 4]

[0082] The results in Table 4 show that after sterilization by gamma irradiation of the formulation of Example 1, impurities B and C increased significantly, and a single large unknown impurity appeared. In Examples 2 to 4, impurity E increased slightly compared to Example 6, but no significant changes were observed in other impurities. The results of the related substances show that the impurities in the formulation after irradiation increased significantly and did not meet the impurity limit requirements, while the impurities in the formulation prepared by solvent removal technology did not increase significantly and were able to meet the impurity limit requirements.

[0083] Experimental Example 4: In vivo plasma concentration of rotigotine in-situ gel formulation in rats Male SD rats (N=6) were selected to study the in vivo pharmacokinetics (PK) behavior. Some formulations from the above examples were subcutaneously injected at a dose of 5 mg / kg (equivalent to rotigotine). Blood was collected from the tail vein at predetermined time points, and the plasma samples were subjected to SPE (Solid-Phase Extraction) and then the rotigotine concentration was measured by LC-MS / MS. The in vivo drug concentration measurement results for the formulations from Examples 1 and 4 in rats are shown in Table 5, and the time-course curves of drug concentration are shown in Figure 1.

[0084] [Table 5]

[0085] The results in Table 5 and Figure 1 show that the in vivo kinetic behaviors of the drugs in the formulations of Example 4 and Example 1 in rats were consistent, and the sterile rotigotine in-situ gel prepared by the solvent removal technique did not affect the in vivo release characteristics of the formulations.

Claims

1. 1. A method for producing an in-situ gel formulation, comprising: i: A step of uniformly mixing the biodegradable polymer and volatile solvent in the production raw materials, and, if desired, some or all of the remaining components in the production raw materials, to obtain a raw material solution I; ii: A step of filtering and sterilizing the raw material liquid I to obtain a sterile raw material liquid I; iii) removing the volatile solvent from the sterile raw material liquid I; In addition, when the raw material solution I does not contain all of the raw materials, iv: a step of uniformly mixing the product obtained in step iii with sterile production raw materials not contained in the raw material solution I under sterile conditions, A method for producing an in-situ gel formulation, wherein the manufacturing material further comprises an active pharmaceutical ingredient, a non-volatile solvent, and optionally a release-modifying agent.

2. When the raw material solution I does not contain all of the raw materials, in step iv, the raw material solution obtained in step iii and the raw materials not contained in the raw material solution I are uniformly mixed by one or more of the following methods (a) to (g): (a) adding the sterile active pharmaceutical ingredient via a sterile delivery device; (b) filtering and sterilizing the solution of the active pharmaceutical ingredient and the non-volatile solvent before adding; (c) sterile filtering and adding a solution of the active pharmaceutical ingredient and the release-modifying agent, if present; (d) if present, filtering and sterilizing the solution of the active pharmaceutical ingredient, the non-volatile solvent, and the release-modifying agent before adding it; (e) adding the non-volatile solvent after sterilization by filtration; (f) if present, filtering and sterilizing the solution of the non-volatile solvent and the release-modifying agent before adding; (g) if present, sterilizing the release-modifying agent before adding it; Preferably, when the raw material solution I does not contain all of the production raw materials, the raw material solution I satisfies any one of the following conditions (j) to (p): (j) the raw material solution I contains the active pharmaceutical ingredient and the non-volatile solvent, but does not contain the release-modifying agent; (k) the raw material solution I contains the active pharmaceutical ingredient and the release-modifying agent, but does not contain the non-volatile solvent; (l) the raw material solution I contains the active pharmaceutical ingredient and does not contain the non-volatile solvent or the release-modifying agent; (m) the raw material solution I contains the non-volatile solvent and the release-modifying agent, but does not contain the active pharmaceutical ingredient; (n) the raw material solution I contains the non-volatile solvent and does not contain the active pharmaceutical ingredient and the release-modifying agent; (o) the raw material solution I contains the release-modifying agent, but does not contain the active pharmaceutical ingredient or the non-volatile solvent; (p) The manufacturing method according to claim 1, wherein the raw material solution I does not contain the active pharmaceutical ingredient, the non-volatile solvent, and the release-regulating agent.

3. the volatile solvent is selected from a volatile alkane, a volatile halogenated alkane, a volatile alcohol, a volatile ketone, a volatile ester, a volatile organic cyanide or a volatile ether; The method according to claim 1 or 2, wherein the mass ratio of the volatile solvent to the biodegradable polymer in the raw materials is preferably 10:1 to 1:

1.

4. The method according to any one of claims 1 to 3, wherein the volatile solvent is selected from the group consisting of dichloromethane, chloroform, and acetone.

5. The method according to any one of claims 1 to 4, wherein in the step iii, the volatile solvent is removed from the sterile raw material solution I by one or more methods selected from the group consisting of reduced pressure, temperature control, aeration, and stirring.

6. The method according to any one of claims 1 to 5, wherein the biodegradable polymer is selected from polyesters, polyester copolymers, and block copolymers.

7. The method according to any one of claims 1 to 6, wherein the biodegradable polymer is selected from PLGA, PLA, PCL, POE, PEG-PLA, PLA-PEG-PLA, PEG-PLGA, PEG-PLGA-PEG, TPGS-PLGA, or TEG-POE.

8. The method according to any one of claims 1 to 7, wherein the non-volatile solvent is N-methylpyrrolidone and / or dimethyl sulfoxide.

9. the optional release-modifying agent is one or more selected from ethyl acetate, medium chain triglycerides, glyceryl triacetate, glyceryl tricaprylate, benzyl benzoate, and benzyl alcohol; A process according to any one of claims 1 to 8, characterized in that the optionally present release modifier is preferably benzyl benzoate and / or glyceryl triacetate.

10. An in-situ gel preparation produced by the method according to any one of claims 1 to 9.

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