Abstract: Silanol hyaluronic acid compound (SHAC) was synthesized from sodium hyaluronate and chlorodimethylsilane suspended in organic phase using tetrabutylammonium iodide as catalyst.The product compound was precipitated by adding ethyl acetate to the filtrate of the reaction product mixture.The skin irritation,cytotoxicity and skin care effect of SHAC product were investigated.In test for back of rabbits that smeared with SHAC of mass fraction 1%,all the cumulative score for erythema and hydropsy is zero.It denotes that SHAC has no skin irritation.IC₅₀ of SHAC is higher than 5 g·L^-1 that is much higher than 1.5 g·L^-1,which is the EU standard criteria for no cytotoxicity.It shows that SHAC exhibits no cytotoxicity.Under environment of air relative humidy 65% and 30%,the moisture content of pig skin after smeared with SHAC achieves (49±2.16)% and (45±2.27)% respectively,which is better than that smeared with sodium hyaluronate that is widely used as humectant.The survival rate of keratinocyte that acted with 0.001 g·L^-1 mass concentration of SHAC achieves (106.0±6.2)% that is no significant differences as comparing with that acted by epidermal growth factor (EGF).

Key words: humectant, hyaluronate, silanization, cytotoxicity