To provide a method for suppressing lowering of molecular weight due to incident decomposition of hyaluronic acid when dehydroacetic acid, sodium dehydroacetate or both of them are used in an aqueous preparation containing hyaluronic acid, hyaluronate or a mixture of hyaluronic acid and hyaluronate.
This method for suppressing hyaluronic acid preparation comprises formulating an aqueous preparation comprising hyaluronic acid, a hyaluronate or both of them and dehydroacetic acid, sodium dehydroacetate or both of them with at least one kind of compounds selected from the group comprising ethylene diamine tetraacetic acid, diethylene triamine heptaacetate, trans-1,2-diaminocyclohexane, glycol ether diamine tetraacetate, citric acid and their salts. Further, the aqueous preparation is a main medicine of opththalmic agent, otolaryngologic agent or ointment.
KAWAI KATSUHIRO
UMEDA TOSHIHIKO
KITAGAWA HIROYUKI
DENKI KAGAKU KOGYO KK