INHIBITOR AGAINST FORMATION OF CROSSLINK IN COLLAGEN

PROBLEM TO BE SOLVED: To obtain the subject inhibitor free from a problem regarding safety, capable of inhibiting the formation of crosslink in collagen, manifesting aging- resistant effects by repairing flabbiness of the skin and recovering the firm state of the skin, and useful as a skin preparation for external use, etc., by including a medicinal agent such as a hydrolyzed casein and L-lysin. SOLUTION: This inhibitor is obtained by formulating one or more kinds selected from (A) a hydrolyzed casein, (B) L-lysin and (C) L-arginine. For example, the inhibitor is obtained by using the casein obtained by hydrolyzing a milk casein by using a trypsin and a subtilisin by two step reaction, and substituting the hydrolyzed casein to dialysis to desalt and purify the casein, and the preparation for external use can be obtained by formulating about 0.0001-20 wt.% objective inhibitor expressed in terms of a dried material based on the whole amount, and optionally further formulating a bleaching agent, a humectant an antioxidant, an oily component or the like besides the foregoing component.