The moisturizer, the rough skin improvement medicine and skin external use medicine

摘要

PROBLEM TO BE SOLVED: To obtain a moisturizer that has the moisturizing effect and skin- roughening-improving effect with excellent safety and stability to oxidation and low skin irritation by using a specific lower alkyl tetritol ether as an active ingredient. ;SOLUTION: This moisturizer contains a lower alkyl tetritol ether of the formula: A-Rn (A is the tetritol residue except n hydrogen atom; R is a 1-4C alkyl having a straight or branched chain, an unsaturated alkyl ; n is an average substitution degree and 1-4) a an active ingredient. This lower alkyl tetritol ether is prepared by mixing (A) tetritol as erythritol, when necessary, dissolved in a solvent, with (B) a compound of (i) the formula: X-R (an eliminating group as Br, I, mesyl, OH) or (ii) a compound of the formula (R₁-R₄ are each an alkyl in which the total carbon atoms is 2 in R₁-R₄) and allowing them to react with each other in the presence of a catalyst at 0-130°C.;COPYRIGHT: (C)1999,JPO