The present invention relates to a cross-linked sodium hyaluronate gel for tissue filler for plastic surgery and the preparation method thereof. The alkaline solution of sodium hyaluronate reacts with the long chain alkane containing epoxy group and the cross-linking agent containing epoxy group for 2˜5 hours at 35° C.˜50° C. to produce cross-linked sodium hyaluronate, then washed, gelled and sterilized, to prepare the gel. Among which, the molar ratio of sodium hyaluronate:cross-linking agent containing epoxy group:long chain alkane containing epoxy group is 10:4˜1:1˜4; the number of carbon atoms of the said long chain alkane containing epoxy group is 6 to 18. The gel prepared in the present invention can, on one hand, effectively enhance the resistance to enzymolysis to become more stable, and on the other hand, maintain the excellent biocompatibility of sodium hyaluronate without affecting its injectability.
Crosslinked sodium hyaluronate gel for surgical plastic surgery and preparation method thereof：
The invention relates to a preparation method of cross-linked sodium hyaluronate gel for surgical plastic surgery, which is characterized by comprising the following steps:
(1) Sodium hyaluronate dry powder was dispersed in 10? wt%～20? A mixed solution composed of wt% sodium hydroxide aqueous solution and acetone was used to obtain sodium hyaluronate basic suspension, and then crosslinking agent 1,4? Butanediol diglycidyl ether BDDE is mixed evenly to obtain the reaction material, so as to start the reaction to produce cross-linked sodium hyaluronate; Under the stirring state, the reaction is completed after the reaction material is kept at 35 ℃ ~ 50 ℃ for 5 ~ 8 hours, and the pH value of the solid-liquid mixed material after the reaction is adjusted to 7 with concentrated hydrochloric acid; Wherein the concentration of sodium hyaluronate in the reaction material is 2? Wt% ~ 5wt%, the mass ratio of crosslinking agent to sodium hyaluronate is (1: 1.3) ~ (1 : 1.8);
(2) Filtrate the solid and liquid mixture of pH=7 after the reaction to remove the liquid. The remaining material is washed with acetone to GC? MS to detect the content of BDDE below 2ppm. The remaining materials include white powder and transparent gel, and then the dried materials are vacuum dried to obtain water-insoluble white dry powder, namely, cross linked sodium hyaluronate powder.
(3) Sieving and separating the crosslinked sodium hyaluronate powder obtained by vacuum drying in step ② and collecting the sieved powder;
(4) Adding deionized water to the sieved powder collected in step 3, so that the cross-linked sodium hyaluronate powder is fully swollen and purified for 6~10 hours at room temperature from 15 to 35 degrees, and the gel particles are collected to obtain crosslinked sodium hyaluronate gel.
(5) The isotonic PBS buffer was added to the gel collected at step 4 and purified for 6~10 hours at room temperature from 15 to 35 degrees. After filtration, PBS was removed and gel was collected. The gel was sequentially screened by using the first specification and second specifications of screen. 3 different sizes of gels were obtained, and 3 gels were sterilized and filled in a pre sterilized disposable syringe.