Cyclic monoterpene extract from cardamom oil as a skin permeation enhancerfor indomethacin: In vitro and in vivo studies

The in vitro and in vivo effect of pretreatment by cardamom oil, a crude dr ug extract, in ethanol/water vehicles on the transdermal delivery of indome thacin was investigated, The cyclic monoterpene components in cardamom oil were also determined and quantified in this study. The permeation of indome thacin was significantly enhanced after pretreatment of cardamom oil both i n the in vitro and in vivo studied. The result of various pretreatment peri ods showed that the indomethacin flux decreased as the length of the pretre atment increased. Both natural cardamom oil and a cyclic monoterpene mixtur e composed of the components of the oil showed similar enhancement on indom ethacin permeation, indicating cyclic monoterpenes are the predominant comp onents altering the barrier property of stratum corneum. The results also s howed that three minor components in cardamom oil (alpha-pinene, 6.5%; beta -pinene, 4.8%; alpha-terpineol, 0.4%) had a synergistic. effect with 1,8-ci neole (59.3%) and d-limonene (29.0%) to enhance the permeation of indometha cin.