CN115350325B - Degradable polymer microsphere with low organic solvent residue, injection preparation, preparation method and application - Google Patents

Abstract

The invention belongs to the field of non-surgical medical cosmetology, and relates to degradable polymer microspheres with low organic solvent residues, an injection preparation, a preparation method and application thereof. The method comprises the following steps: step 1, fully mixing a polymer solution with an aqueous solution containing an emulsifier to obtain microsphere emulsion; step 2, injecting the microsphere emulsion in the step 1 into an aqueous solution containing a stabilizer, and continuously performing airflow disturbance to obtain microsphere suspension for removing the organic solvent; and step 3, sieving by a liquid circulation mode, re-suspending the obtained target particle size microspheres, sieving by a liquid circulation mode to obtain treated microspheres, and drying. The degradable polymer microsphere not only reduces the organic solvent to below 10ppm, but also has more controllable particle size and morphology of finished microsphere on the basis of higher safety, and the injection preparation obtained by adopting the degradable polymer microsphere can be quickly redissolved, has no aggregation and precipitation and keeps good dispersibility.

Description

Degradable polymer microsphere with low organic solvent residue, injection preparation, preparation method and application

Technical Field

The invention belongs to the field of non-surgical medical cosmetology, and relates to degradable polymer microspheres with low organic solvent residues, an injection preparation, a preparation method and application thereof.

Background

The non-surgical minimally invasive medical beauty project and the light medical beauty project are more easily accepted by consumers due to the factors of high safety, low risk, small wound and the like, so that the market acceptance and the repurchase rate are both higher. The degradable polyester material comprises polylactic acid, polyglycolic acid, polycaprolactone and the like, and can achieve the filling effect by exciting the skin to generate collagen hyperplasia as a regenerative face injection product, and the filling effect is more natural and longer in duration than a physical filling product. The us FDA approved poly-l-lactic acid (PLLA) as an injectable implant in 2004 for the repair of cotton-padded intolerance in HIV patients and 2009 for the treatment of nasolabial folds and other wrinkle sites. The components of the products in the market at present are mainly poly-L-lactic acid particles or microspheres. In 2021, two poly-L-lactic acid microsphere products obtain registration certificate of III type medical instruments in China and are formally marketed and sold. The microparticle product is prepared by crushing and sieving poly-L-lactic acid, has irregular shape, is easier to agglomerate compared with microsphere products, increases injection difficulty and pain feeling, and has certain potential safety hazard. The preparation method of the poly-L-lactic acid microsphere comprises a solvent volatilization method, a spray drying method, a membrane emulsification method and the like, wherein the solvent volatilization method is easy to operate and is easier to prepare in a large scale because the equipment requirement is low. Patent CN110051882a describes a method for preparing polylactic acid microsphere, which comprises dissolving polylactic acid in dichloromethane to form polymer solution, adding aqueous solution of polyvinyl alcohol, high-speed shearing and emulsifying, removing solvent, and freeze drying to obtain polylactic acid microsphere; in the patent CN102516565B, polylactic acid organic solution is dispersed into aqueous phase medium, and then the polylactic acid microsphere is obtained through ion, water washing and freeze drying after stirring to make the organic solvent completely volatilize.

However, the existing injectable microsphere preparation for non-operative beauty has two main problems, namely, the problem of organic solvent residue in the microsphere preparation process and the problem of long reconstitution time during storage, transportation and use of microsphere dry powder. Although the solvent volatilization method can keep the microsphere state, the time is long, the volatilization period is generally more than 24 hours, and the organic solvent inside the microsphere is difficult to completely volatilize through stirring action, so that residues are caused. The freeze drying method has the advantages of long time consumption, high energy consumption, high cost and high equipment use requirement, and is not beneficial to large-scale production. The solvent extraction method has low efficiency and has the problem of residual introduced new solvent. The decompression heating method is the most commonly used method for removing the organic solvent residues at present, but in the slow temperature rising process, when the temperature is close to the glass transition temperature of the polymer, adhesion aggregation can occur among the microspheres, so that the morphology and the yield of the microspheres are affected, and the organic solvent residues in the microspheres can be caused. In addition, although the residual amount of the organic solvent can be reduced to a certain extent by the method, the residual amount of the organic solvent in the microsphere still remains at a relatively high level and is difficult to reduce to a low level (< 50 ppm), so that the clinical use safety of the microsphere preparation cannot be ensured. Polylactic acid microspheres disclosed in the patent CN105193735A and the patent CN105214145A are obtained by a conventional emulsification-solvent evaporation method, and have the problem of large solvent residue (about 0.5%). Patent CN111973561a provides a method for removing organic solvent residues in microspheres by the combined action of a plurality of water washes such as pre-washing, hot water washing and cold water washing, and the method can effectively solve the problem of organic solvent residues, but the process has more complicated operation steps and larger resource loss, and cannot be applied to actual production.

Therefore, there is a need to develop a method for preparing biodegradable polymer microspheres by reducing the residual amount of toxic solvents and organic solvent mixtures, and controlling the toxic and harmful residual solvents within safe limits without affecting the morphology of the microsphere product.

In clinical use, microspheres are prepared into uniformly dispersed injection by adopting a re-dissolution mode, and microsphere adhesion can be generated due to insufficient re-dissolution. After the product is fully reconstituted, the product is injected on the face, and the product needs to be kneaded at the injection site on the face after injection to prevent microsphere aggregation. Even so, adverse reactions such as subcutaneous nodules and red swelling can be caused in actual use.

Taking polylactic acid microspheres as an example, most of the existing products are polylactic acid freeze-dried powder, the particle size of the microspheres is smaller, and is usually smaller than 100 microns, physiological saline and the like are required to be injected for re-dissolution when the product is used, the complete re-dissolution is generally difficult, the re-dissolution time is too long, and the phenomenon of blocking a needle head also occurs during clinical injection. In order to solve the problem of re-dissolution of microsphere products, patent CN104258470A prepares polylactic acid microspheres and sodium hyaluronate into mixed gel containing salt solution, and adopts a pre-filling injection mode for use, but polylactic acid microsphere materials can be slowly degraded in an aqueous environment, so that the use effect and the shelf life of the product after being put on shelf can be influenced. Patent CN102911380a discloses a method for preparing composite gel by crosslinking and grafting hyaluronic acid and biodegradable polymer, which also requires dichloromethane, and residual solvent is not easy to remove, thus affecting the use safety. The polylactic acid microsphere freeze-dried powder and a suspending agent (instant solvent) are packaged separately, when the method is used, the suspending agent system is prepared into a solution with a certain concentration, and the solution is added into the microsphere dry powder to realize re-dissolution, but the method does not fundamentally solve the problems that the microsphere dry powder is easy to aggregate and difficult to store, and the re-dissolution rate is also influenced by the dissolution rate of the suspending agent.

The particle size, solvent residue and the using method of the polymer degradable microsphere have great influence on filling effect, safety and practical operation. Meanwhile, the volatilization process of the organic solvent has great influence on the morphology of the microsphere. Therefore, in view of the effectiveness, safety, economy of microsphere production, convenience of use, and the like of microsphere filling, there is a need for a simple and easy preparation method for degradable microspheres, which is suitable for large-scale preparation, has high yield of microspheres with effective particle diameters, and low organic solvent residue, and a solution of slow reconstitution injection use mode, and the method is a technical problem to be solved at present.

Disclosure of Invention

Aiming at the technical problems existing in the prior art, the invention aims to provide a degradable polymer microsphere with low organic solvent residue, an injection preparation, a preparation method and application thereof, wherein the degradable polymer microsphere not only reduces the organic solvent to below 10ppm, but also can not influence the morphology of a microsphere product and ensure the regularity of the appearance of the microsphere, has a smooth microscopic appearance, and has more controllable particle size and morphology of the microsphere finished product on the basis of higher safety; meanwhile, the defects of long re-dissolution time, bonding aggregation and uneven injection of the existing microspheres of the injection preparation are overcome, and the injection preparation prepared from the degradable polymer microspheres can be quickly re-dissolved without aggregation and precipitation, and keeps good dispersibility.

In a first aspect, the present invention provides a method for preparing a degradable polymeric microsphere, comprising:

Step 1, mixing a degradable polymer and an organic solvent to obtain a polymer solution; then, the polymer solution is used as a disperse phase and is fully mixed with the continuous phase of the aqueous solution containing the emulsifier to obtain microsphere emulsion;

Step 2, injecting the microsphere emulsion in the step 1 into an aqueous solution containing a stabilizer, wherein the temperature of the aqueous solution containing the stabilizer is the volatilizable temperature of the organic solvent, and simultaneously, continuously introducing protective gas from the bottom of the mixed solution upwards to continuously perform air flow disturbance to obtain microsphere suspension for removing the organic solvent;

Step 3, sieving the microsphere suspension obtained in the step 2 in a liquid circulation mode, and screening microspheres with target particle diameters; re-suspending the obtained target particle size microspheres with absolute ethyl alcohol, and sieving the target particle size microspheres with a liquid circulation mode to obtain treated microspheres;

And 4, drying the treated microspheres obtained in the step 3.

The weight average molecular weight of the degradable polymer according to the invention can be selected within a wide range, in a preferred embodiment of the invention the weight average molecular weight of the degradable polymer is 10000-500000g/mol.

According to the present invention, the degradable polymer may be selected from a wide range, including but not limited to one or more selected from polylactic acid, polyglycolic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polydioxanone, polyamino acid derived carbonate, polyorthoester, polyhydroxyalkanoate, polytrimethylene carbonate, oxalate-containing polymer, polydioxanone ester, polyacetal and polyanhydride;

in a preferred embodiment of the present invention, the degradable polymer is selected from one or more of polylactic acid, polyglycolic acid, polycaprolactone, polylactic acid-glycolic acid copolymer.

In a more preferred embodiment of the present invention, the degradable polymer is selected from polylactic acid, preferably, the polylactic acid is selected from a blend or copolymer of one or more of levorotatory polylactic acid, dextrorotatory polylactic acid, racemic polylactic acid, meso-polylactic acid, or a blend or copolymer of one or more of levorotatory polylactic acid, dextrorotatory polylactic acid, meso-polylactic acid with an absorbable polymer; the absorbable polymer is selected from one or more of the following polymers: polyglycolic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polydioxanone, polyamino acid derived carbonate, polyorthoester, polyhydroxyalkanoate, polytrimethylene carbonate, oxalate-containing polymer, polydioxanone, polyacetal, polyanhydride.

According to the present invention, the organic solvent may be selected within a wide range, and in a preferred embodiment of the present invention, the organic solvent is methylene chloride or a solvent formed of methylene chloride and an organic solvent miscible with methylene chloride; preferably, the organic solvent which is miscible with dichloromethane is selected from one of chloroform, ethyl acetate, acetone, acetonitrile, dimethyl sulfoxide, dimethylformamide and methyl ethyl ketone, preferably one of chloroform, acetone and tetrahydrofuran.

The mass percentage of polymer in the polymer solution in step 1 according to the invention can be chosen within a wide range, in a preferred embodiment of the invention, in step 1: the mass percentage of the polymer in the polymer solution is 1-20%, preferably 4-10%.

According to the invention, the mass percentage of the emulsifier in the aqueous solution containing the emulsifier in step 1 may be selected within a wide range, and in a preferred embodiment of the invention the mass percentage of the emulsifier in the aqueous solution containing the emulsifier is 0.5% to 10%, preferably 1% to 4%.

According to the present invention, the emulsifier may be selected within a wide range, and in a preferred embodiment of the present invention, the emulsifier is at least one of polyvinyl alcohol, carboxymethyl chitosan, gelatin, agar, and hyaluronic acid.

According to the invention, the volume ratio of the polymer solution to the emulsifier solution can be selected within a wide range, in a preferred embodiment of the invention the volume ratio of the polymer solution to the emulsifier solution is 1 (1-20), preferably 1 (3-5).

In a preferred embodiment of the present invention, in step 1, the conditions under which the continuous phase is thoroughly mixed include: the temperature is 10-20 ℃, and/or in the step 1, the continuous phase is fully mixed by mechanical stirring; preferably, the shear rate of the mechanical agitation is from 100 to 1200rpm, preferably from 700 to 1000rpm; and/or stirring for 5-60min; preferably 8-40min.

According to the invention, the temperature of the aqueous solution containing the stabilizer may be selected within a wide range, and in a preferred embodiment of the invention, the temperature of the aqueous solution containing the stabilizer in step 2 is 40 to 90 ℃.

According to the invention, the volume ratio of the aqueous solution containing a stabilizer to the microsphere emulsion in step 2 may be selected within a wide range, and in a preferred embodiment of the invention the volume ratio of the aqueous solution containing a stabilizer to the microsphere emulsion is 1 (1-5), preferably 1:2-1:3.

The duration of the air flow disturbance according to the invention can be chosen within wide limits, in a preferred embodiment of the invention the duration of the air flow disturbance is 1-2 hours.

According to the present invention, the mass percentage of the stabilizer of the aqueous solution containing the stabilizer may be selected within a wide range, and in a preferred embodiment of the present invention, the mass percentage of the stabilizer of the aqueous solution containing the stabilizer is 2% to 4%.

According to the present invention, the stabilizer may be selected within a broad range, and in a preferred embodiment of the present invention, the stabilizer is selected from one or more of carboxymethyl cellulose, carboxymethyl chitosan, alginate, huang Yuanfen, sodium silicate, polyacrylamide, polyacrylic acid, polyvinylpyrrolidone, polyvinyl alcohol, polymaleic anhydride, polyquaternium, polyethylene glycol, polyethoxylane, hydrophobically modified hydroxyethyl cellulose.

In a preferred embodiment of the present invention, in step 3: the liquid circulation mode is driven by a high-pressure flow pump, and the flow speed of the pressure flow pump is preferably 2.5-6L/h.

In a preferred embodiment of the present invention, the target particle size microspheres are screened using a standard screen, preferably 800 mesh to 250 mesh.

The number of two passes in step 3 according to the invention may be selected within wide limits, and in a preferred embodiment of the invention the number of passes in step 3 is each 3-8.

The drying mode in step 4 may be selected according to the present invention, and may be, for example, natural air drying, vacuum drying or freeze drying. The method for preparing the microsphere can reach less than 10ppm of solvent residue under the condition of forced air drying, and can be considered to have no residue if vacuum drying or freeze drying is adopted and the solvent residue is lower than the detection limit. The preparation method can further reduce the requirement on drying conditions, and the microspheres prepared by the method can be prepared with very low organic solvent residues even without vacuum drying or freeze-drying conditions.

In a preferred embodiment of the present invention, step 4 comprises subjecting the microspheres obtained in step 3 to air-drying to obtain degradable polymer microspheres; preferably, the temperature of the air drying is 20-50 ℃.

In a more preferred embodiment of the present invention, the preparation method of the degradable polymer microsphere comprises the following specific steps:

Step 1, mixing a degradable polymer and an organic solvent to obtain a polymer solution with a certain concentration; fully mixing a polymer solution serving as a disperse phase with an aqueous solution continuous phase containing an emulsifier at the temperature of 10-20 ℃ and mechanically stirring to obtain microsphere emulsion;

Step 2, rapidly injecting the microsphere emulsion into a certain amount of aqueous solution containing a stabilizer at the temperature of 40-90 ℃, and continuously introducing nitrogen upwards from the bottom of the mixed solution to ensure that the microspheres are uniformly dispersed in the stabilizer and prevent adhesion, and continuously volatilizing the organic solvent for 1-2 hours to obtain microsphere suspension;

Step 3, sieving the microsphere suspension by adopting a liquid circulation mode under the action of a high-pressure flow pump, circulating for 3-8 times, sieving microspheres with target particle size, re-suspending the microspheres by using absolute ethyl alcohol, sieving by adopting a liquid circulation mode, circulating for 3-8 times, and reducing microsphere aggregation to obtain treated microspheres;

And step 4, naturally blowing and drying the microspheres at normal temperature to obtain finished microsphere products.

Based on the above preferred embodiments, in step 1, the degradable polymer is selected from one or more of polylactic acid, polyglycolic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polydioxanone, polyamino acid derived carbonate, polyorthoester, polyhydroxyalkanoate, polytrimethylene carbonate, oxalate-containing polymer, polydioxanone, polyacetal, polyanhydride;

preferably one or more selected from polylactic acid, polyglycolic acid, polycaprolactone, and polylactic acid-glycolic acid copolymers;

The polylactic acid is selected from one or a plurality of blends or copolymers of the L-polylactic acid, the D-polylactic acid, the racemized polylactic acid and the meso-polylactic acid, or one or a plurality of blends or copolymers of the L-polylactic acid, the D-polylactic acid, the racemized polylactic acid and the meso-polylactic acid and other absorbable polymers.

Based on the above preferred technical scheme, in step 1, the weight average molecular weight of the degradable polymer is 10000-500000g/mol.

According to the above preferred embodiment, in step 1, the organic solvent is selected from dichloromethane or a mixture of dichloromethane and an organic solvent miscible therewith;

the solvent which can be mutually dissolved with dichloromethane comprises one of chloroform, ethyl acetate, acetone, acetonitrile, dimethyl sulfoxide, dimethylformamide and methyl ethyl ketone, and preferably one of chloroform, acetone and tetrahydrofuran.

Based on the above preferred technical scheme, in step 1, the mass percentage of the polymer in the polymer solution is 1-20%, preferably 4-10%.

Based on the above preferred technical scheme, in step 1, the emulsifier is at least one of polyvinyl alcohol, carboxymethyl chitosan, gelatin, agar, and hyaluronic acid;

The mass percentage of the emulsifier aqueous solution is 0.5-10%, preferably 1-4%.

Based on the above preferred technical scheme, in step 1, the volume ratio of the polymer solution to the emulsifier solution is 1:1-1:20, preferably 1:3-1:5.

Based on the above preferred technical scheme, in step 1, the shearing rate of the mechanical stirring is 100-1200rpm, preferably 700-1000rpm; stirring for 5-60min; preferably 8-40min.

Based on the above preferred technical scheme, in step 2, the stabilizer has the function of maintaining microsphere form when the organic solvent is removed rapidly, and the mass percentage of the stabilizer in the aqueous solution of the stabilizer is 2-4%.

Based on the above preferred technical scheme, in step 2, the volume ratio of the aqueous solution of the stabilizer to the polymer emulsion is 1 (1-5), preferably 1:2-1:3.

Based on the above preferred technical scheme, in step 2, the stabilizer is one or more selected from carboxymethyl cellulose, carboxymethyl chitosan, alginate, huang Yuanfen, sodium silicate, polyacrylamide, polyacrylic acid, polyvinylpyrrolidone, polyvinyl alcohol, polymaleic anhydride, polyquaternium, polyethylene glycol, polyethoxylane, and hydrophobically modified hydroxyethyl cellulose.

Based on the preferable technical scheme, in the step 3, the flow speed of the high-pressure flow pump is 2.5-6L/h.

Based on the above preferred technical scheme, in step 3, the mesh number of the standard sieve used is 800 mesh-250 mesh.

In a second aspect, the present invention provides a degradable polymer microsphere prepared by the preparation method according to the first aspect.

The residue of the organic solvent (including methylene dichloride) in the microsphere finished product obtained by the invention is 10ppm or less; the particle size distribution of the microsphere finished product can be precisely controlled to be 20-60 microns; the microsphere finished product is in a regular sphere shape and has a smooth microscopic appearance.

Aiming at the defects of long re-dissolution time, bonding aggregation and non-uniform injection of the prior microsphere in the injection preparation in the prior art, the third aspect of the invention provides an injection preparation which comprises the degradable polymer microsphere and the dispersing agent in the second aspect.

According to the present invention, the ratio of the degradable polymer microsphere to the dispersing agent can be selected within a wide range, and in a preferred embodiment of the present invention, the mass percentage of the degradable polymer microsphere is 10% to 50%, preferably 25% to 40%, and the mass percentage of the dispersing agent is 50% to 90%, preferably 60% to 75%.

In a preferred embodiment of the invention, the size of the dispersant ranges from 50 to 300 microns.

In a preferred embodiment of the invention, the dispersing agent is a hyaluronic acid forming microgel; preferably, the weight average molecular weight of the hyaluronic acid is 10000-2000000g/mol.

In a preferred embodiment of the invention, the dispersing agent is cross-linked hyaluronic acid, preferably the cross-linking agent used is butanediol glycidyl ether; the content of the crosslinking agent in the crosslinked hyaluronic acid is 0.1% -10% of the mass of the hyaluronic acid, preferably 3% -8%.

The injection preparation of the invention is in the form of foam, flocculent, sheet or block.

In a fourth aspect, the present invention provides a method for preparing the injection preparation according to the third aspect, comprising: mixing degradable polymer microsphere and dispersant, and freeze drying.

In a preferred embodiment of the invention, the temperature of the mixing is 0-4 ℃ and/or the time of freeze-drying is 24-72 hours.

In a preferred embodiment of the present invention, a method for preparing an injection preparation comprises:

Step 1, dispersing hyaluronic acid in an alkaline aqueous solution to obtain a hyaluronic acid solution;

step 2, adding a cross-linking agent into the hyaluronic acid solution, mixing and standing to obtain hyaluronic acid gel;

Step 3, immersing the hyaluronic acid gel obtained in the step 2 in water, and carrying out swelling treatment to obtain the swelled crosslinked hyaluronic acid gel;

Step 4, extruding and sieving the swelled crosslinked hyaluronic acid gel by adopting an external pressure sieving method to obtain gel particles with a target size as a dispersing agent;

And 5, uniformly mixing the degradable polymer microspheres with a dispersing agent, packaging, and freeze-drying to obtain a finished injection preparation.

In the above technical solution, the mass concentration of the alkaline solution in step 1 may be selected within a wide range, and in a preferred embodiment of the present invention, in step 1: the mass concentration of the alkali solution is 0.1% -2%, preferably 0.5% -1%.

The choice of base is a matter of routine in the art and includes, but is not limited to, sodium hydroxide, and is not described in detail herein.

In the above technical solution, the mass concentration of hyaluronic acid in the hyaluronic acid solution may be selected within a wide range, and in a preferred embodiment of the present invention, the mass concentration of hyaluronic acid in the hyaluronic acid solution is 1% -20%, preferably 6% -12%.

In a preferred embodiment of the invention, the temperature in step 1 is from 10 to 20℃and/or the dispersion is carried out by stirring, preferably at a rate of from 50 to 300rpm, for a period of from 24 to 48 hours.

In a preferred embodiment of the invention, the cross-linking agent is used in step 2 in an amount of 0.1% to 10%, preferably 3% to 8% by mass of hyaluronic acid.

In a preferred embodiment of the present invention, the conditions in step 2 include: the mixing temperature is 10-20deg.C, preferably 40-60deg.C, and the standing time is 3-8 hr.

In a preferred embodiment of the present invention, in step 3: the temperature is 10-20 ℃, the pH is 6.5-7.5, and the swelling treatment time is 2-24h.

In a preferred embodiment of the present invention, in step 4: the mesh number of the used sieves is 300-60 mesh.

In a more preferred embodiment of the present invention, the method for preparing an injection preparation comprises:

step 1, dissolving hyaluronic acid in an alkali aqueous solution at the temperature of 10-20 ℃, stirring at a low speed, and uniformly dissolving to prepare a hyaluronic acid solution with a certain concentration;

Step 2, adding a certain amount of cross-linking agent into the hyaluronic acid solution at the temperature of 10-20 ℃, uniformly mixing, and then standing at the temperature of 40-60 ℃ for a certain period of time, wherein the hyaluronic acid solution becomes gel under the action of the cross-linking agent;

And 3, immersing the hyaluronic acid gel obtained in the step 2 into deionized water at the temperature of 10-20 ℃ and neutralizing with dilute hydrochloric acid until the pH value is 6.5-7.5.

Step 4, directly extruding and sieving the fully swelled crosslinked hyaluronic acid gel by adopting an external pressure sieving method at the temperature of 10-20 ℃ to obtain gel particles with the target size as a dispersing agent;

And 5, uniformly mixing the degradable polymer microspheres with a dispersing agent at the temperature of 0-4 ℃, adding the mixture into a penicillin bottle, freeze-drying the penicillin bottle filled with the mixture for 12 hours, and sterilizing to obtain a finished product of the injection.

Based on the above preferred technical scheme, in step 1, the molecular weight of hyaluronic acid is 10000-2000000g/mol; the concentration of the alkali solution is 0.1-2%, preferably 0.5-1%; the concentration of the hyaluronic acid alkali solution is 1-20%, preferably 6-12%.

Based on the above preferred technical scheme, in step 1, the stirring speed is 50-300rpm, and the time is 24-48h.

Based on the above preferred technical scheme, in step 2, the cross-linking agent is butanediol glycidyl ether, the amount of the cross-linking agent is 0.1-10% of the mass of hyaluronic acid, preferably 3-8%, and the reaction time is 3-8h.

Based on the above preferred technical scheme, in step 3, the mesh number of the standard sieve used is 300 mesh-60 mesh.

Based on the above preferred technical scheme, in step 4, the ratio of the degradable polymer microsphere to the dispersant is 1:125-1:500.

In a fifth aspect, the present invention provides an injection comprising a reconstituted solution and an injection preparation according to one of the third aspects or an injection preparation prepared by the preparation method according to the fourth aspect.

In a preferred embodiment of the present invention, the multiple solution is at least one of distilled water, physiological saline, phosphate buffer, and simulated body fluid.

According to the invention, which can be chosen within wide limits, in a preferred embodiment of the invention the ratio of the mass of the injectable formulation to the mass of the reconstituted solution is 1: (1-5).

The invention relates to a preparation method of injection. Adding a compound solution into the prepared injection preparation, slightly shaking, and obtaining a suspension after the compound solution is dissolved.

When in use, the suspension is kept stand for defoaming, and the defoamed suspension is extracted by a syringe for use.

The injection provided by the invention can be completely dissolved within 30min, and the degradable polymer microspheres can be uniformly and well suspended in the solution and stably dispersed for more than 1 h. After standing for 24 hours, the degradable polymer microspheres are not obviously aggregated or precipitated, and still maintain good dispersibility.

In a sixth aspect, the present invention provides a degradable polymer microsphere according to the second aspect, an injection preparation according to the third aspect or an injection preparation prepared by a preparation method according to the fourth aspect, or an application of an injection preparation according to the fifth aspect in the field of non-surgical cosmetology. For example, the composition may be used as a cosmetic material or an auxiliary agent for a cosmetic material, or a cosmetic material not intended for medical treatment.

The microspheres in the injection disclosed by the invention are well dispersed, do not adhere, have small organic solvent residue and are safer, so that the injection disclosed by the invention can be used for improving wrinkles, repairing soft tissues or expanding the volume, correcting contours or filling shallow to deep nasolabial folds and other facial wrinkles, and has higher safety.

According to the technical scheme, compared with the prior art, the invention has the advantages that:

1. The inventor of the present invention has found through research that methylene dichloride is easy to volatilize during emulsification in the prior art, and is easy to phase separate from a polymer during the emulsification process, so that the emulsification is unstable, the present invention preferably adopts emulsification at a lower temperature (preferably 10-20 ℃), the polymer solution is stable, the sphericity of the microsphere is ensured, and the residual amount of organic solvents including methylene dichloride can be reduced to below 10ppm by adopting the subsequent specific method.

2. The inventor of the present invention also found through research that the prior art generally uses long-time magnetic stirring to volatilize methylene dichloride, the speed is low, the sphericity of the microspheres is affected, and as the microspheres are solidified, a part of solvent is solidified inside the microspheres, so that residues are caused. According to the invention, the polymer solution is introduced into hot water with a certain temperature, and under the continuous airflow disturbance of the protective gas, dichloromethane can be rapidly diffused into the disperse phase, so that the microsphere product form is not influenced, the regularity of the microsphere appearance is ensured, the organic solvent can be rapidly volatilized on the surface and in the microsphere, the dichloromethane residue is greatly reduced, and the post-treatment time is greatly shortened.

3. The method of screening (preferably high-pressure flow screening) in combination with ethanol cleaning is adopted, so that the step of centrifugally collecting microspheres in the prior art is omitted, the aggregation of the microspheres and the residue of an emulsifying agent can be reduced simultaneously, the screening efficiency is improved, the yield of the microspheres with the target particle size is increased, the equipment use requirement is reduced, and the large-scale production is easy.

4. The microgel formed by sieving the dispersing agent (preferably crosslinked hyaluronic acid gel) is mixed with the degradable polymer microsphere to prepare an injection preparation, and after being mixed with a compound solution (such as physiological saline and the like), the injection preparation can be quickly redissolved, the redissolved degradable microsphere is uniformly dispersed in the gel, the stability can be maintained after long-term storage (such as standing for 24 hours), the sedimentation or layering phenomenon can not occur, the problems that the redissolved time of the injectable microsphere preparation is overlong, the redissolved is incomplete, and meanwhile, some chemical reagents with larger toxicity can not be introduced, so that the instant use can be realized, and the injection use performance of the product can be thoroughly improved.

Based on the technical scheme, the preparation method of the degradable polymer microsphere is simple and easy to implement, does not need special equipment, and is easy for mass production. The obtained degradable polymer microsphere finished product has good sphericity, smooth surface, low dichloromethane residue and high yield of target particle diameter microsphere, and is an economic, efficient and safe microsphere preparation method. The invention mixes the microsphere dry powder and the dispersing agent (preferably crosslinked hyaluronic acid) and freeze-dries the mixture into foam, flocculent, flaky or block, and when in use, the compound solution (such as physiological saline and the like) is directly added, the compound solution has short compound solution time (less than 21 min), no aggregation and precipitation and good dispersibility, solves the problems of long compound solution time, uneven suspension and needle blocking for injection in the prior injection, and greatly improves the safety and the use effect on human bodies.

Drawings

FIG. 1 is a scanning electron microscope image of the degradable polymer microspheres of example 1;

FIG. 2 is a scanning electron microscope image of the degradable polymeric microspheres of example 4;

FIG. 3A scanning electron microscope image of the injectable formulation in example 7.

Detailed Description

The present invention is described in detail below with reference to specific embodiments, and it should be noted that the following embodiments are only for further description of the present invention and should not be construed as limiting the scope of the present invention, and some insubstantial modifications and adjustments of the present invention by those skilled in the art from the present disclosure are still within the scope of the present invention.

In the following examples, degradable polymers such as poly (L-lactic acid) pellets, polycaprolactone, poly (lactic acid-glycolic acid) and the like are purchased from chemical reagent companies such as microphone, carbofuran, sheen s and the like, and have weight average molecular weights of 10000-500000g/mol;

the polyvinyl alcohol is 1788-L, purchased from Anhui View New materials Co., ltd,

Gelatin is used in microbiology, gel strength 250g,

The weight average molecular weight of the hyaluronic acid is 200000-2000000g/mol,

The substitution degree of carboxymethyl chitosan is more than or equal to 80 percent.

EXAMPLE 1 preparation of degradable Polymer microspheres with Low organic solvent residues

2G of polylactic acid granules are weighed and dissolved in 50ml of dichloromethane to be fully dissolved, so as to prepare polylactic acid solution. The polylactic acid solution was mixed as a dispersed phase with 180ml of a 2% aqueous polyvinyl alcohol solution continuous phase at 10℃and mechanically stirred at 800rpm for 15min at 15℃to obtain an oil-in-water emulsion. The oil-in-water emulsion is rapidly introduced into a 1.5% carboxymethyl chitosan aqueous solution at 50 ℃ and 500ml, and simultaneously, nitrogen is continuously introduced from the bottom of the mixed solution upwards, so that the microspheres are uniformly dispersed in the stabilizer and prevented from adhesion, and the solvent methylene dichloride is fully volatilized after 2 hours, so as to obtain microsphere suspension. Sieving the microsphere suspension with a liquid circulation mode at a flow rate of 4L/h under the action of a high-pressure flow pump, and circulating for 5 times to select the microspheres of 20-60 microns. Suspending the screened microspheres with absolute ethyl alcohol, sieving by using a liquid circulation mode, circulating for 5 times, and reducing microsphere aggregation to obtain the treated microspheres. And naturally air-drying the fully treated microspheres to obtain polylactic acid microsphere finished products.

FIG. 1 is a scanning electron microscope image of the degradable polymer microsphere in example 1, and it can be seen that the obtained microsphere has a smooth outer surface and a particle size distribution in the range of 20-60 μm.

EXAMPLE 2 preparation of degradable Polymer microspheres with Low organic solvent residues

2G of polylactic acid granules are weighed and dissolved in 50ml of dichloromethane to be fully dissolved, so as to prepare polylactic acid solution. The polylactic acid solution was mixed as a dispersed phase with 180ml of a 2% gelatin aqueous continuous phase at 10℃and mechanically stirred at 900rpm for 15min at 15℃to obtain an oil-in-water emulsion. The oil-in-water emulsion is rapidly introduced into the aqueous solution of sodium alginate with the concentration of 1.5 percent at 60 ℃ and 500ml, and simultaneously, nitrogen is continuously introduced from the bottom of the mixed solution upwards, so that the microspheres are ensured to be uniformly dispersed in the stabilizer and prevented from adhesion, and the solvent methylene dichloride is kept for 2 hours to fully volatilize, so as to obtain microsphere suspension. Sieving the microsphere suspension with a liquid circulation mode at a flow rate of 4L/h under the action of a high-pressure flow pump, and circulating for 5 times to select the microspheres of 20-60 microns. Suspending the screened microspheres with absolute ethyl alcohol, sieving by using a liquid circulation mode, circulating for 5 times, and reducing microsphere aggregation to obtain the treated microspheres. And naturally air-drying the fully treated microspheres to obtain polylactic acid microsphere finished products.

EXAMPLE 3 preparation of degradable Polymer microspheres with Low organic solvent residues

2G of polylactic acid granules are weighed and dissolved in 50ml of dichloromethane to be fully dissolved, so as to prepare polylactic acid solution. The polylactic acid solution was mixed as a dispersed phase with 180ml of a 2% aqueous hyaluronic acid solution continuous phase at 10℃and mechanically stirred at 800rpm for 15min at 15℃to obtain an oil-in-water emulsion. The oil-in-water emulsion is rapidly introduced into 70 ℃ and 500ml of 1.5% polyethylene glycol 2000 aqueous solution, and simultaneously, nitrogen is continuously introduced from the bottom of the mixed solution upwards, so that the microspheres are uniformly dispersed in the stabilizer and prevented from adhesion, and the solvent methylene dichloride is fully volatilized after 2 hours, so as to obtain microsphere suspension. Sieving the microsphere suspension with a liquid circulation mode at a flow rate of 4L/h under the action of a high-pressure flow pump, and circulating for 5 times to select the microspheres of 20-60 microns. Suspending the screened microspheres with absolute ethyl alcohol, sieving by using a liquid circulation mode, circulating for 5 times, and reducing microsphere aggregation to obtain the treated microspheres. And naturally air-drying the fully treated microspheres to obtain polylactic acid microsphere finished products.

EXAMPLE 4 preparation of degradable Polymer microspheres with Low organic solvent residues

2G of polycaprolactone was weighed and dissolved in 50ml of dichloromethane to prepare a polylactic acid solution. The polylactic acid solution was mixed as a dispersed phase with 180ml of a 2% aqueous polyvinyl alcohol solution continuous phase at 10℃and mechanically stirred at 1000rpm for 30 minutes at 10℃to obtain an oil-in-water emulsion. The oil-in-water emulsion is rapidly introduced into 60 ℃ and 650ml of 1.5% carboxymethyl chitosan aqueous solution, and simultaneously, nitrogen is continuously introduced from the bottom of the mixed solution upwards, so that the microspheres are uniformly dispersed in the stabilizer and prevented from adhesion, and the solvent methylene dichloride is fully volatilized after 2 hours, so as to obtain microsphere suspension. Sieving the microsphere suspension with a liquid circulation mode at a flow rate of 4L/h under the action of a high-pressure flow pump, and circulating for 5 times to select the microspheres of 20-60 microns. Suspending the screened microspheres with absolute ethyl alcohol, sieving by using a liquid circulation mode, circulating for 5 times, and reducing microsphere aggregation to obtain the treated microspheres. And naturally air-drying the fully treated microspheres to obtain polylactic acid microsphere finished products.

FIG. 2 is a scanning electron microscope image of the degradable polymer microsphere in example 4, which shows that the obtained microsphere has smooth outer surface and particle size distribution in the range of 20-60 μm.

EXAMPLE 5 preparation of degradable Polymer microspheres with Low organic solvent residues

3G of the polylactic acid-glycolic acid copolymer was weighed and dissolved in 50ml of methylene chloride to prepare a polylactic acid solution. The polylactic acid solution was mixed as a dispersion phase with 250ml of a 3% aqueous polyvinyl alcohol solution continuous phase at 10℃and mechanically stirred at 700rpm for 20 minutes at 20℃to obtain an oil-in-water emulsion. The oil-in-water emulsion is rapidly introduced into the aqueous solution of carboxymethyl chitosan with the temperature of 60 ℃ and 800ml of 1.5%, and simultaneously, nitrogen is continuously introduced upwards from the bottom of the mixed solution, so that the microspheres are uniformly dispersed in the stabilizer and prevented from adhesion, and the solvent dichloromethane is fully volatilized after 2 hours, so as to obtain microsphere suspension. Sieving the microsphere suspension with a liquid circulation mode at a flow rate of 5L/h under the action of a high-pressure flow pump, and circulating for 5 times to select the microspheres of 20-60 microns. Suspending the screened microspheres with absolute ethyl alcohol, sieving by using a liquid circulation mode, circulating for 5 times, and reducing microsphere aggregation to obtain the treated microspheres. And naturally air-drying the fully treated microspheres to obtain polylactic acid microsphere finished products.

EXAMPLE 6 preparation of degradable Polymer microspheres with Low organic solvent residues

4G of polylactic acid granules are weighed and dissolved in 50ml of dichloromethane to be fully dissolved, so as to prepare polylactic acid solution. The polylactic acid solution was mixed as a dispersed phase with 200ml of a 3% aqueous polyvinyl alcohol solution continuous phase at 10℃and mechanically stirred at 750rpm for 10 minutes at 18℃to obtain an oil-in-water emulsion. The oil-in-water emulsion is rapidly introduced into a 1.5% carboxymethyl chitosan aqueous solution at 60 ℃ and 700ml, and simultaneously, nitrogen is continuously introduced from the bottom of the mixed solution upwards, so that the microspheres are uniformly dispersed in the stabilizer and prevented from adhesion, and the solvent methylene dichloride is fully volatilized after 2 hours, so as to obtain microsphere suspension. Sieving the microsphere suspension with a liquid circulation mode at a flow rate of 5L/h under the action of a high-pressure flow pump, and circulating for 5 times to select the microspheres of 20-60 microns. Suspending the screened microspheres with absolute ethyl alcohol, sieving by using a liquid circulation mode, circulating for 5 times, and reducing microsphere aggregation to obtain the treated microspheres. And naturally air-drying the fully treated microspheres to obtain polylactic acid microsphere finished products.

Examples 7-9 preparation of injectable formulations

The proportions and preparation conditions of the injection preparations of examples 7-9 are shown in Table 1, and the preparation method comprises the following steps:

(1) Dissolving a required amount of hyaluronic acid in an alkali aqueous solution (sodium hydroxide aqueous solution, weight of 2%) at 15 ℃, stirring at a low speed, and uniformly dissolving to prepare a hyaluronic acid alkali solution with a required concentration;

(2) Adding a required amount of cross-linking agent into the hyaluronic acid solution at 20 ℃, uniformly mixing, and then standing at 40 ℃ for a certain period of time, wherein the hyaluronic acid solution becomes gel under the action of the cross-linking agent;

(3) Selecting standard mesh number in table 1 at 10deg.C, directly squeezing and sieving the obtained crosslinked hyaluronic acid gel to obtain gel particles with target size as dispersing agent;

(4) At 4 ℃, a certain amount of the degradable polymer microsphere prepared in the example 1 is taken and evenly mixed with the dispersing agent, the mixture is added into a penicillin bottle, the penicillin bottle filled with the mixture is freeze-dried for 12 hours, and the injection finished product is obtained after sterilization.

Fig. 3 is a scanning electron microscope image of the injection preparation in example 7, and it can be seen that the microspheres are distributed inside the freeze-dried hyaluronic acid.

TABLE 1

Comparative example 1 emulsion-solvent volatilization to prepare degradable Polymer microspheres

At room temperature, 2g of polylactic acid granules are weighed and dissolved in 50ml of dichloromethane to be fully dissolved, so as to prepare polylactic acid solution. The polylactic acid solution was mixed as a dispersed phase with 180ml of a 2% aqueous polyvinyl alcohol solution continuous phase and mechanically stirred at 800rpm for 15min at 15℃to obtain an oil-in-water emulsion. The oil-in-water emulsion was warmed to 40 ℃ and mechanically stirred at 300rpm for 24 hours to give a microsphere suspension. The microsphere suspension was screened and rinsed 5 times with deionized water. And then washing 5 times by absolute ethyl alcohol to obtain the microspheres with the specified size after treatment. And freeze-drying the fully treated microspheres for 12 hours to obtain polylactic acid microsphere dry powder.

Dichloromethane residue test

The degradable polymeric microsphere materials obtained in examples 1 to 6, comparative example 1 were quantitatively tested for methylene chloride residue using a 7890A-5975C gas chromatograph-mass spectrometer, and the results are shown in Table 2. Mass spectrometry conditions: the electrons bombard the ionization source, selecting the ion mode (SIM) m/z 49, 84.

Analytical procedure

1 Sample treatment

Directly weighing 10.00g (accurate to 0.01 g) of the sample into a 50mL volumetric flask, adding methanol to the scale, and capping and sealing. Vortex oscillating on vortex oscillator until the sample is completely dissolved or uniformly mixed, and transferring 10.0mL sample solution to the headspace sample bottle. Taking 1mL of upper gas after gas-liquid balance, and entering gas chromatography for detection.

2 Headspace sampler conditions

The headspace sampler conditions were as follows:

a) Vaporization chamber temperature: 80 ℃, quantitative tube temperature: 90 ℃, transmission line temperature: 100 ℃;

B) Gas-liquid equilibrium time: 30min.

3 Reference conditions for gas chromatography

The gas chromatography reference conditions were as follows:

A) Chromatographic column: HP-VOC,30 m.times.0.2 mm.times.1.1 μm;

B) Column temperature: keeping at 35 ℃ for 2min;

C) Sample inlet temperature: 250 ℃;

d) Split ratio: 50:1;

E) Flow rate: l.0mL/min.

Drawing 4 standard working curve

Respectively sucking 10mL of standard working solution of each level into a headspace bottle, and detecting according to 3 medium chromatographic conditions. Linear regression was performed with the concentrations of the standard working solutions (dichloromethane 0.05. Mu.g/mL, 0.10. Mu.g/mL, 0.50. Mu.g/mL, 1.0. Mu.g/mL, 5.0. Mu.g/mL, 10. Mu.g/mL, 1-trichloroethane 0.0010. Mu.g/mL, 0.0020. Mu.g/mL, 0.010. Mu.g/mL, 0.020. Mu.g/mL, 0.20. Mu.g/mL, 0.50. Mu.g/mL) at each stage as the abscissa and the corresponding peak areas as the ordinate to obtain the standard curve equation.

5 Measurement

Taking a standard working solution and the sample in the step 1 according to the 3 chromatographic condition, and obtaining a standard curve and the peak area of the sample solution. The concentration of the target compound in the sample solution is determined from the standard curve. The methylene chloride and 1,1 trichloroethane contents of the samples should be determined, if necessary, from the average of the results of two independent parallel tests.

6 Blank test

The procedure was followed except that the sample was not weighed.

7 Result calculation

The content of the object to be detected in the sample is calculated according to the formula:

Wherein:

X-the contents of the methylene dichloride and the 1, 1-trichloroethane to be detected in the sample are expressed in milligrams per kilogram (mg/kg);

Concentration of dichloromethane and 1, 1-trichloroethane in micrograms per milliliter (μg/mL) as measured by the C-standard curve;

v-volume of sample solution in milliliters (mL);

M-mass of sample in grams (g).

TABLE 2 residual dichloromethane content

Detection of particle size of degradable polymer microsphere material

The average particle diameters of the degradable polymer microspheres in examples 1 to 6 and comparative example 1 were measured by a dynamic light scattering method, and the results are shown in Table 3.

TABLE 3 particle size of degradable polymeric microsphere materials

Comparative example 2 comparative reconstitution Effect

The reconstitution time and reconstitution effect of the injection formulations obtained in examples 7-9 were compared with the commercial skin-filled injection formulation product (comparative example 2) and the test results are shown in table 4.

Test of reconstitution Effect

The injection preparations prepared in examples 7 to 9, the commercially available microsphere injection preparation (comparative example 2) and the injection preparation in comparative example 3 were weighed, thoroughly mixed with 5mL of sterile water for injection, shaken up and down, and the reconstitution time and the effect after reconstitution of the injection were observed.

TABLE 4 reconstitution Effect

The injection preparation prepared by the microspheres in examples 2-6 according to the method of example 7 is re-dissolved according to the method, and no aggregation and precipitation exist after re-dissolution, so that good dispersibility is maintained.

It should be noted that the above-described embodiments are only for explaining the present invention and do not constitute any limitation of the present invention. The invention has been described with reference to exemplary embodiments, but it is understood that the words which have been used are words of description and illustration, rather than words of limitation. Modifications may be made to the invention as defined in the appended claims, and the invention may be modified without departing from the scope and spirit of the invention. Although the invention is described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, as the invention extends to all other means and applications which perform the same function.

All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art. In case of conflict, the present specification, definitions, will control.

When the specification derives materials, substances, methods, steps, devices, or elements and the like in the word "known to those skilled in the art", "prior art", or the like, such derived objects encompass those conventionally used in the art as the application suggests, but also include those which are not currently commonly used but which would become known in the art to be suitable for similar purposes.

The endpoints of the ranges and any values disclosed in this document are not limited to the precise range or value, and the range or value should be understood to include values approaching the range or value. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein. In the following, the individual technical solutions can in principle be combined with one another to give new technical solutions, which should also be regarded as specifically disclosed herein.

In the context of this specification, any matters or matters not mentioned are directly applicable to those known in the art without modification except as explicitly stated.

Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or ideas thus formed are all deemed to be part of the original disclosure or original description of the present invention, and should not be deemed to be a new matter which has not been disclosed or contemplated herein, unless such combination is clearly unreasonable by those skilled in the art.

Claims (39)

1. A method of preparing a degradable polymeric microsphere comprising:

step 1, mixing a degradable polymer and an organic solvent to obtain a polymer solution; then mixing the polymer solution as a disperse phase with an aqueous solution continuous phase containing an emulsifier to obtain microsphere emulsion;

Step 2, injecting the microsphere emulsion in the step 1 into an aqueous solution containing a stabilizer, wherein the temperature of the aqueous solution containing the stabilizer is the volatilizable temperature of the organic solvent, and simultaneously, continuously introducing protective gas from the bottom of the mixed solution upwards to continuously perform air flow disturbance to obtain microsphere suspension for removing the organic solvent;

Step 3, sieving the microsphere suspension obtained in the step 2 in a liquid circulation mode, and screening microspheres with target particle diameters; re-suspending the obtained target particle size microspheres with absolute ethyl alcohol, and sieving the target particle size microspheres with a liquid circulation mode to obtain treated microspheres;

step 4, drying the treated microspheres obtained in the step 3;

the organic solvent is dichloromethane or a solvent formed by dichloromethane and an organic solvent which can be mutually dissolved with the dichloromethane;

in step 1, the conditions for mixing the polymer solution as a dispersed phase with the continuous phase of the aqueous solution containing the emulsifier include: the temperature is 10-20 ℃.

2. The method of manufacturing according to claim 1, characterized in that:

the weight average molecular weight of the degradable polymer is 10000-500000g/mol; and/or the number of the groups of groups,

The degradable polymer is selected from one or more of polylactic acid, polyglycolic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polydioxanone, polyamino acid derived carbonate, polyorthoester, polyhydroxyalkanoate, polytrimethylene carbonate, oxalate-containing polymer, polydioxanone, polyacetal and polyanhydride.

3. The method of manufacturing according to claim 1, characterized in that:

The degradable polymer is selected from one or more of polylactic acid, polyglycolic acid, polycaprolactone and polylactic acid-glycolic acid copolymer.

4. The method of manufacturing according to claim 1, characterized in that:

the degradable polymer is selected from polylactic acid.

5. The method of manufacturing according to claim 4, wherein:

the polylactic acid is selected from one or a mixture or a copolymer of a plurality of L-polylactic acid, D-polylactic acid, racemized polylactic acid and meso-polylactic acid, or one or a mixture or a copolymer of a plurality of L-polylactic acid, D-polylactic acid, racemized polylactic acid and meso-polylactic acid and an absorbable polymer;

the absorbable polymer is selected from one or more of the following polymers:

polyglycolic acid, polylactic acid-glycolic acid copolymers, polycaprolactone, polydioxanone, polyamino acid derived carbonates, polyorthoesters, polyhydroxyalkanoates, polytrimethylene carbonates, oxalate containing polymers, polydioxanes, polyacetals, polyanhydrides.

6. The method of manufacturing according to claim 1, characterized in that:

The organic solvent which can be mutually dissolved with methylene dichloride is selected from one of chloroform, ethyl acetate, acetone, acetonitrile, dimethyl sulfoxide, dimethylformamide and methyl ethyl ketone.

7. The method of manufacturing according to claim 1, characterized in that:

the organic solvent which can be mutually dissolved with methylene dichloride is selected from one of chloroform, acetone and tetrahydrofuran.

8. The preparation method according to one of claims 1 to 7, characterized in that:

In step 1:

In the polymer solution, the mass percentage of the polymer is 1% -20%; and/or the number of the groups of groups,

The mass percentage of the emulsifier in the aqueous solution containing the emulsifier is 0.5-10%; and/or the number of the groups of groups,

The emulsifier is at least one of polyvinyl alcohol, carboxymethyl chitosan, gelatin, agar and hyaluronic acid; and/or the number of the groups of groups,

The volume ratio of the polymer solution to the aqueous solution containing the emulsifier is 1 (1-20).

9. The method of manufacturing according to claim 8, wherein:

In step 1:

in the polymer solution, the mass percentage of the polymer is 4% -10%; and/or the number of the groups of groups,

The mass percentage of the emulsifier in the aqueous solution containing the emulsifier is 1-4%; and/or the number of the groups of groups,

The volume ratio of the polymer solution to the aqueous solution containing the emulsifier is 1 (3-5).

10. The preparation method according to one of claims 1 to 7, characterized in that:

in step 1, the conditions for mixing the polymer solution as a dispersed phase with the continuous phase of the aqueous solution containing the emulsifier include: the mixing mode is mechanical stirring.

11. The method of manufacturing according to claim 10, wherein:

the shear rate of the mechanical stirring is 100-1200rpm; and/or stirring for 5-60min.

12. The method of manufacturing according to claim 10, wherein:

The shear rate of the mechanical stirring is 700-1000 rpm; and/or stirring for 8-40min.

13. The preparation method according to one of claims 1 to 7, characterized in that:

in step 2:

the temperature of the aqueous solution containing the stabilizer is 40-90 ℃; and/or the number of the groups of groups,

The volume ratio of the aqueous solution containing the stabilizer to the microsphere emulsion is 1 (1-5); and/or the number of the groups of groups,

The duration of the air flow disturbance is 1-2h.

14. The method of manufacturing according to claim 13, wherein:

The volume ratio of the aqueous solution containing the stabilizer to the microsphere emulsion is 1:2-1:3.

15. The preparation method according to one of claims 1 to 7, characterized in that:

the mass percentage of the stabilizer of the aqueous solution containing the stabilizer is 2% -4%; and/or the number of the groups of groups,

The stabilizer is one or more selected from carboxymethyl cellulose, carboxymethyl chitosan, alginate, huang Yuanfen, sodium silicate, polyacrylamide, polyacrylic acid, polyvinylpyrrolidone, polyvinyl alcohol, polymaleic anhydride, polyquaternium, polyethylene glycol, polyethoxylane and hydrophobically modified hydroxyethyl cellulose.

16. The preparation method according to one of claims 1 to 7, characterized in that:

In step 3:

The liquid circulation mode is driven by a high-pressure flow pump; and/or screening the microspheres with the target particle size by adopting a standard sieve;

and/or, the number of times of sieving twice in the step3 is 3-8 respectively.

17. The method of manufacturing according to claim 16, wherein:

In step 3:

the liquid circulation mode is driven by a high-pressure flow pump, and the flow speed of the high-pressure flow pump is 2.5-6L/h; and/or screening the microspheres with the target particle size by adopting a standard sieve, wherein the mesh number of the standard sieve is 800-250 meshes.

18. The preparation method according to one of claims 1 to 7, characterized in that:

the drying method in the step 4 comprises the step of carrying out air flow drying on the microspheres obtained in the step 3 to obtain the degradable polymer microspheres.

19. The method of manufacturing according to claim 18, wherein:

the temperature of the air flow drying is 20-50 ℃.

20. A degradable polymeric microsphere prepared according to the preparation method of any one of claims 1 to 19.

21. The degradable polymeric microsphere of claim 20, wherein:

the particle size distribution range of the degradable polymer microspheres is 20-60 microns, and/or the residual total amount of the organic solvent in the degradable polymer microspheres is not higher than 10 ppm; and/or the number of the groups of groups,

The degradable polymeric microspheres are regular spherical and have a smooth microscopic appearance.

22. An injectable formulation comprising the degradable polymeric microsphere of claim 20 or 21 and a dispersing agent.

23. The injection formulation of claim 22, wherein:

The mass percentage of the degradable polymer microsphere is 10-50%, the mass percentage of the dispersing agent is 50-90%, and/or the size of the dispersing agent is 50-300 microns.

24. The injection formulation of claim 23, wherein:

the mass percentage of the degradable polymer microsphere is 25-40%, and the mass percentage of the dispersing agent is 60-75%.

25. Injection formulation according to claim 23 or 24, characterized in that:

The dispersing agent is microgel formed by hyaluronic acid.

26. The injection formulation of claim 25, wherein:

The weight average molecular weight of the hyaluronic acid is 10000-2000000g/mol.

27. The injection formulation of claim 22, wherein:

The dispersing agent is cross-linked hyaluronic acid.

28. The injectable formulation of claim 27, wherein:

The cross-linking agent used in the cross-linked hyaluronic acid is butanediol glycidyl ether;

The content of the cross-linking agent in the cross-linked hyaluronic acid is 0.1-10% of the mass of the hyaluronic acid.

29. The injectable formulation of claim 27, wherein:

The cross-linking agent used in the cross-linked hyaluronic acid is butanediol glycidyl ether;

the content of the cross-linking agent in the cross-linked hyaluronic acid is 3-8% of the mass of the hyaluronic acid.

30. A method of preparing an injectable formulation according to any one of claims 22 to 29 comprising:

mixing degradable polymer microsphere and dispersant, and freeze drying.

31. The method of preparing an injectable formulation of claim 30, wherein:

Mixing the degradable polymer microspheres and the dispersing agent, wherein the mixing temperature is 0-4 ℃; and/or freeze-drying for 24-72h.

32. The method of preparing an injectable formulation according to claim 30 or 31, comprising:

Step 1, dispersing hyaluronic acid in an alkaline aqueous solution to obtain a hyaluronic acid solution;

step 2, adding a cross-linking agent into the hyaluronic acid solution, mixing and standing to obtain hyaluronic acid gel;

Step 3, immersing the hyaluronic acid gel obtained in the step 2 in water, and carrying out swelling treatment to obtain the swelled crosslinked hyaluronic acid gel;

Step 4, extruding and sieving the swelled crosslinked hyaluronic acid gel by adopting an external pressure sieving method to obtain gel particles with a target size as a dispersing agent;

And 5, uniformly mixing the degradable polymer microspheres with a dispersing agent, packaging, and freeze-drying to obtain a finished injection preparation.

33. The method of manufacturing according to claim 32, wherein:

In step 1:

The mass concentration of the alkaline water solution is 0.1% -2%; and/or the number of the groups of groups,

The mass concentration of the hyaluronic acid in the hyaluronic acid solution is 1% -20%; and/or the number of the groups of groups,

The temperature is 10-20deg.C, and/or the dispersion is stirring.

34. The method of manufacturing according to claim 33, wherein:

In step 1:

The mass concentration of the aqueous alkali solution is 0.5% -1%; and/or the number of the groups of groups,

The mass concentration of the hyaluronic acid in the hyaluronic acid solution is 6% -12%; and/or the dispersing mode is stirring, the stirring speed is 50-300rpm, and the time is 24-48h.

35. The method of manufacturing according to claim 32, wherein:

The dosage of the cross-linking agent in the step 2 is 0.1-10% of the mass of the hyaluronic acid; and/or, the conditions in step 2 include: the mixing temperature is 10-20 ℃; and/or the number of the groups of groups,

In step 3: the temperature is 10-20 ℃, the pH is 6.5-7.5, and the swelling treatment time is 2-24h; and/or the number of the groups of groups,

In step 4: the mesh number of the used sieves is 300-60 mesh.

36. The method of manufacturing according to claim 35, wherein:

The dosage of the cross-linking agent in the step 2 is 3-8% of the mass of the hyaluronic acid; and/or, the conditions in step 2 include: the mixing temperature is 10-20 ℃, the standing temperature is 40-60 ℃, and the standing time is 3-8h.

37. An injection comprising a reconstituted solution and an injection formulation according to any one of claims 22 to 29 or a preparation prepared by a method according to any one of claims 30 to 36.

38. An injection according to claim 37, wherein:

The compound solution is at least one of distilled water, normal saline, phosphate buffer solution and simulated body fluid; and/or the mass ratio of the injection preparation to the reconstituted solution is 1: (1-5).

39. Use of a degradable polymeric microsphere according to claim 20 or 21, an injectable formulation according to any one of claims 22 to 29 or a injectable formulation prepared by a method according to any one of claims 30 to 36, or an injectable formulation according to claim 37 or 38 in the field of non-surgical cosmetology.