| 摘要 |
<p>A low-molecular-weight acetylated hyaluronic acid having the following characteristics and an emollient containing the same as the active ingredient: limiting viscosity: 50 - 200 cm3/g, number of acetyl groups: 2.6 - 3.6 (except N-acetyl groups). The emollient can exhibit excellent emollient and humectant effects while appropriately controlling the stringiness of the hyaluronic acid. The process for producing the acid comprises suspending powdery hyaluronic acid in a solution of acetic anhydride and adding concentrated sulfuric acid to the solution to effect acetylation. The process for purifying the acid comprises adding crude acetylated hyaluronic acid to an aqueous solution of acetone, adding sodium lactate to the solution to effect dissolution of the acid, and precipitating high-purity acetylated hyaluronic acid by adding a high-concentration acetone solution.</p> |
