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CN-121991383-A - Preparation method of crosslinked hyaluronic acid gel

CN121991383ACN 121991383 ACN121991383 ACN 121991383ACN-121991383-A

Abstract

The application provides a preparation method of crosslinked hyaluronic acid gel and a preparation containing microspheres and crosslinked hyaluronic acid gel. The preparation method comprises the following steps of (1) mixing hyaluronic acid or salt thereof, a cross-linking agent and an alkaline solution to obtain a mixed solution, (2) carrying out primary cross-linking reaction on the mixed solution to obtain first gel, (3) cutting the first gel into pieces, adding the first gel into the alkaline solution containing hyaluronic acid or salt thereof to carry out secondary cross-linking reaction to obtain second gel, and (4) purifying the second gel to obtain cross-linked hyaluronic acid gel. The prepared hyaluronic acid gel has excellent cohesive force, microspheres can be uniformly dispersed in the hyaluronic acid gel only in a very short time, and after the hyaluronic acid gel is mixed with the microspheres, the microspheres can be uniformly distributed in the crosslinked hyaluronic acid gel for a long time, and displacement, sedimentation and agglomeration are not easy to occur.

Inventors

  • WU ZIXIANG
  • CHEN YI
  • ZHAO TONGTONG
  • DONG LIANGRUN
  • WANG SINING
  • SU YANG

Assignees

  • 华熙生物科技(海南)有限公司

Dates

Publication Date
20260508
Application Date
20241108

Claims (10)

  1. 1. A method for preparing a crosslinked hyaluronic acid gel, comprising the steps of: Step (1), mixing hyaluronic acid or salt thereof, a cross-linking agent and an alkaline solution to obtain a mixed solution; Step (2), performing primary crosslinking reaction on the mixed solution to obtain first gel; cutting the first gel into pieces, and then adding the pieces into an alkaline solution containing hyaluronic acid or salt thereof to carry out secondary crosslinking reaction to obtain second gel; And (4) purifying the second gel to obtain the crosslinked hyaluronic acid gel.
  2. 2. The production method according to claim 1, wherein the molecular weight of the hyaluronic acid or a salt thereof is 800kDa-3000kDa.
  3. 3. The production method according to claim 1 or 2, wherein the mass content of the hyaluronic acid or a salt thereof in the mixed solution is 4% to 20%.
  4. 4. The production method according to any one of claims 1 to 3, wherein the crosslinking agent is added in an amount of 0.5% to 10% by weight of the hyaluronic acid or a salt thereof.
  5. 5. The production process according to any one of claims 1 to 4, wherein the alkaline solution has a pH of 9 to 14.
  6. 6. The production process according to any one of claims 1 to 5, wherein the temperature of the crosslinking reaction in step (2) is 20 to 50 ℃ for 1 to 8 hours.
  7. 7. The production method according to any one of claims 1 to 6, wherein the crosslinking agent is ethylene glycol diglycidyl ether, 1, 4-butanediol diglycidyl ether, or polyglycidyl ether.
  8. 8. The production process according to any one of claims 1 to 7, wherein the mass content of the hyaluronic acid or a salt thereof in the alkaline solution containing the hyaluronic acid or a salt thereof in the step (3) is 0.2% to 2.2%, Preferably, the temperature of the secondary crosslinking reaction in step (3) is 20-50 ℃ and the time is 4-15h.
  9. 9. A crosslinked hyaluronic acid gel prepared according to the preparation method of any of claims 1-8.
  10. 10. A microsphere-containing preparation comprising the crosslinked hyaluronic acid gel and microspheres prepared by the preparation method of any one of claims 1-8, wherein the microspheres have an average particle size of 10-120 μm, preferably the mass content of the microspheres is 6% -50% based on the total mass of the crosslinked hyaluronic acid gel and microspheres, Further preferably, the microsphere comprises a poly (l-lactic acid) microsphere, a polycaprolactone microsphere, a polymethyl methacrylate microsphere, or a hydroxyapatite microsphere.

Description

Preparation method of crosslinked hyaluronic acid gel Technical Field The application belongs to the technical field of injection facial fillers, and particularly relates to a preparation method of crosslinked hyaluronic acid gel and a preparation containing microspheres and crosslinked hyaluronic acid gel. Background The microsphere soft tissue filler is a novel biostimulating soft tissue filler, can stimulate collagen regeneration, and has obvious and durable curative effects on improving facial volume loss, wrinkles and facial contours caused by aging. The microsphere soft tissue filler generally comprises polymer microspheres and dispersion liquid, when the polymer microspheres are implanted subcutaneously, foreign body reaction can be generated, and collagen is finally stimulated to generate through the processes of protein absorption, cell aggregation, fiber embedding and the like, so that the effect of improving and tightening skin is achieved. Common dispersions are hyaluronic acid, cellulose. Among them, hyaluronic acid is a high molecular polysaccharide, which is widely present in connective tissue, epithelial tissue and nerve tissue of the human body. It has good moisture-keeping property, biocompatibility and biodegradability. In cosmetology, hyaluronic acid is commonly used to fill wrinkles, correct facial contours, and the like. Common polymer microspheres include poly-L-lactic acid (PLLA), polycaprolactone (PCL), polymethyl methacrylate (PMMA), hydroxyapatite (CaHA) and the like, and unlike traditional soft tissue fillers, microsphere materials are generally hydrophobic, are easy to settle after being mixed with low-viscosity dispersion liquid, and are easy to aggregate after being mixed with high-viscosity dispersion liquid. And aggregation or sedimentation of the microspheres can lead to the failure of uniform distribution of the microspheres in the dispersion liquid, influence the safety and effectiveness of the microsphere soft tissue filler product, and cannot obtain an ideal filling effect. Taking CaHA microspheres as an example, caHA is one of main components of human bones, and has excellent biocompatibility and bioactivity. The CaHA microsphere is combined with hyaluronic acid gel, so that the stability and durability of the filling agent can be improved. CaHA microspheres can be used as a skeleton after being injected into tissues to promote the generation of collagen, and hyaluronic acid gel provides an instant filling effect. In preparing hyaluronic acid gels containing CaHA microspheres, it is desirable to solve the problem of uniform dispersion of CaHA microspheres in the gel and to avoid sedimentation and aggregation of the microspheres during injection. In the prior art, patent CN115282339B discloses a preparation method of a cross-linked hyaluronic acid/hydroxyapatite injectable material, which is characterized in that photo-cross-linked sodium hyaluronate and PEG modified CaHA microspheres are mixed and photo-cured to obtain a cross-linked hyaluronic acid/hydroxyapatite filler, the preparation process is complicated, HAMA is firstly prepared, caHA microspheres modified by CaHA are prepared, time is wasted, residues in each reaction are difficult to remove, and after HAMA and CaHA are mixed, microspheres are unevenly distributed due to the fact that CaHA microspheres have larger density and are settled in uncrosslinked HAMA solution, and patent application CN104853742A provides a preparation method of an injectable sterile aqueous preparation based on cross-linked hyaluronic acid and hydroxyapatite for therapeutic and cosmetic application, however, the mixed gel obtained by the preparation method can avoid sedimentation of hydroxyapatite particles, the hydroxyapatite particles in the mixed gel are difficult to uniformly distribute, and the hydroxyapatite particles are easy to shift and accumulate in the injection process to influence injection. Therefore, how to uniformly distribute polymer microspheres in a dispersion liquid and reduce sedimentation and aggregation of the microspheres is a technical problem to be solved in the field of microsphere soft tissue fillers. Disclosure of Invention Aiming at the problems existing in the prior art, the application provides a preparation method of crosslinked hyaluronic acid gel, which can ensure uniform distribution of microspheres in the crosslinked hyaluronic acid gel for a long time after the crosslinked hyaluronic acid gel obtained by the method is mixed with microspheres, and reduce sedimentation and aggregation of the microspheres. In particular, the application relates to the following aspects: 1. A method for preparing a crosslinked hyaluronic acid gel, comprising the steps of: Step (1), mixing hyaluronic acid or salt thereof, a cross-linking agent and an alkaline solution to obtain a mixed solution; Step (2), performing primary crosslinking reaction on the mixed solution to obtain first gel; cutting the first gel into piece