Enhancement effect of essential oils from the fruits and leaves of Alpinia oxyphylla on skin permeation and deposition of indomethacin

Abstract

Essential oils from plants are gaining increasing attention as potential chemical penetration enhancers. This study aimed to investigate the enhancement effect of essential oils from the fruits and leaves of Alpinia oxyphylla on skin permeation and deposition of indomethacin. In vitro permeation experiments were performed in Franz-type cells through rat skin, and the amount of drug passing through into the receptor phase was analyzed by ultra performance liquid chromatography-photodiode array (UPLC-PDA). Ultra fast liquid chromatography coupled with tandem mass spectrometry (UFLC-MS/MS) was used to analyze the plasma drug concentration of indomethacin to examine the enhancement effect of essential oils in an in vivo rat model of drug delivery. Both oils demonstrated a significant enhancement effect on drug delivery and skin deposition (p < 0.05). Particularly, at 3% concentration, enhancement ratios of fruit oil and leaf oil were 10.16 and 4.61, respectively, which were both significantly higher than that of the commonly used enhancer, Azone (2.04). Major constituents of both oils were identified by gas chromatography-mass spectrometry (GC-MS). It may be deduced that higher content hydrocarbon terpenes in the fruit oil contribute to the increased enhancement effect relative to leaf oil. The skin irritation test indicated that both oils at certain concentrations (1%, 3%, and 5%) did not cause obvious erythema or edema in rabbits. Considering their enhanced drug permeation and low skin irritation, essential oils from Alpinia oxyphylla could be novel penetration enhancers and have promising applications in transdermal drug delivery and cosmetics.