[Effects of penetration enhancers on in vitro percutaneous absorption and amount retained in skin of paeonol, dictamnine, fraxinellone and glycyrrhetinic acid in Liangfu cream].

Objective: To study the effects of different penetration enhancers on the in vitro percutaneous absorption and amount retained in skin of active ingredients in Liangfu cream and to screen out the effective accelerator.

Method: Using improved Franz-type difusion cell and excised small mouse skin in vitro as transdermal barrier, the amount retained in skin and kinetics parameters of active ingredients such as cumulative permeation quantity, permeation rate and permeation lagged time were determined by HPLC. The enhancement ability of four different enhancers such as azone, oleic acid, transcutol P and isopropyl myristate were investigated.

Result: 3% IPM enhanced the cumulative permeation quantity better than other penetration enhancers. The enhancive permeation multiples of paeonol, dictamnine, fraxinellone and glycyrrhetinic acid were 1.52, 1.24, 1.73 and 3.21 times (P < 0.05). The enhancive amount retained in skin multiple of glycyrrhetinic acid was 1.96 times (P < 0.05), but for other components there were no significant impacts.

Conclusion: The effects of penetration enhancers on the in vitro percutaneous absorption and amount retained in skin of components in Liangfu cream are different. 3% IPM which can enhance the cumulative permeation quantity of four components and amount retained in skin of glycyrrhetinic acid is the most suitable penetration enhancer for Liangfu cream.