A prep work technique of Salt Acetylated Hyaluronate, making up the complying with steps:
( 1) hyaluronic acid or its salt in acetic acid and acetic anhydride blended solvent, carry out acylation response under the catalysis of vitriol oil;
( 2) after the reaction is ended up, the response fluid is added into water for precipitation, the coarse precipitation is collected, as well as the acetylated hyaluronic acid is obtained after washing with water;
( 3) The pH worth of the acetylated hyaluronic acid in step (2) is adapted to be nearly neutral with alkaline remedy, as well as after being diluted with water, filteringed system and also spray-dried to get the acetylated salt hyaluronate.
Wherein, the hyaluronic acid salt is sodium salt, potassium salt, magnesium salt, calcium salt, zinc salt or ammonium salt of hyaluronic acid, and the molecular weight is 50-3000kDa.
Wherein, the proportion of acetic acid as well as acetic anhydride blended solvent in the blended solvent in the described action (1) is 1:1 ～ 4(v/v); the proportion of hyaluronic acid or its salt to the blended solvent is 1:10 ～ 50 (w/v); the quantity of concentrated sulfuric acid made use of make up 1% to 5% of the complete quantity of the reaction solution.
Wherein, the acylation response temperature of the step (1) is 5-40 ° C., and also the response is finished when the response solution is transparent.
Wherein, the amount of water made use of in the precipitation as well as washing in step (2) is respectively 2 to 20 times the complete quantity of the reaction solution.
Wherein, in step (3 ), the lye service is a remedy consisting of salt hydroxide, sodium carbonate, sodium bicarbonate, sodium phosphate or disodium hydrogen phosphate, and the changed pH worth is 4-8, preferably 5-7.
Wherein, symphonious (3 ), the proportion of the total volume of the Sodium Acetylated Hyaluronate remedy to the hyaluronic acid or its salt after being weakened with water is 5-50 mL:1 g.
Wherein, symphonious (3 ), the inlet air temperature of the spray drying out devices is 100-200 ° C, and the outlet air temperature is 70-120 ° C.
The Sodium Acetylated Hyaluronate prepared by the above technique has an average replacement level of acetyl team of 2.5 to 3.7, preferably 2.8 to 3.5, ideally 2.9 to 3.4, a lot more ideally 3.0 to 3.3; inherent viscosity is 0.1 to 2.3 dL/g, preferably 0.3 to 1.5 dL/g, more ideally 0.5 to 1.2 dL/g. Extensively utilized in the preparation of medications, cosmetics, clinical materials and feed ingredients.