Capsaicin and nonivamide as novel skin permeation enhancers for indomethacin

The study was conducted in vitro to investigate the changes of indomethacin transdermal permeation pretreated by capsaicin and nonivamide, two compoun ds chemically similar to Atone. The combined effect of low frequency ultras ound (20 kHz) and enhancers on the indomethacin permeation was also evaluat ed. The experimental data demonstrated that capsaicin and nonivamide signif icantly enhanced the flux of indomethacin across nude mouse skin. Enhanceme nt effects of both analogues were very similar and depended predominantly o n the concentration tested. Histological examination coupled with visual sc ores indicated the safety of capsaicin and nonivamide on skin structure. Si multaneous application of ultrasound and enhancers significantly increased skin permeation of indomethacin compared with either ultrasound or enhancer s alone. Better effect was obtained by the combination with capsaicin than nonivamide. (C) 2001 Elsevier Science B.V. All rights reserved.