| 摘要 |
PURPOSE:To obtain an external drug having suppressed browning tendency of arbutin with time, by using arbutin having skin-beautifying effect in combination with sodium bisulfite. CONSTITUTION:The objective external drug for skin contains arbutin (hydroquinone-beta-D-glucopyranoside) and sodium bisulfite at a weight ratio of 1:0.0001-1 (preferably 1:0.001-0.1). The amount of arbutin in the whole drug is 1-20wt.%. Arbutin is active to inhibit tyrosinase which is an enzyme participating in the formation of melanin pigment and exhibits skin-beautifying effect, however, it has a tendency to discolor from pale yellow to brown with time under exposure to sun light or by the storage at a high temperature. The defect can be eliminated by using sodium bisulfite especially at pH 4-7. |
