Chemical constituents and bioactivity of Kalimeris indica Limonoids from Dictamnus angustifolius Effects of penetration enhancers on in vitro percutaneous absorption and amount retained in skin of paeonol, dictamnine, fraxinellone and glycyrrhetinic acid in Liangfu cream Determination of fraxinellone in root bark of Dictamnus dasycarpus by RP-HPLC Dermatopharmacokinetic studies of Liangfu cream in rat skin Simultaneous determination of three active compounds in root barks ofDictamnus dasycarpus by RP-HPLC