Transdermal delivery character of sinomenine microemulsion

AIM:To prepare O/W microemulsion formulation containing sinomenine and investigate the effect of different penetration enhancers on transermal delivery character of microemulsion in vitro. METHODS: The microemulsions were prepared and characterized using Zetasize potential/particle size analysis instrument.The stability tests were performed to evaluate the sinomenine microemulsions.Franz diffusion cell was adopted as the apparatus for in vitro transdermal test.Excised Wistar-rat abdomen skin was pretreated with penetration enhancers,such as menthol,borneol and isopropyl myristate. RESULTS: The average droplet size of the microemulsion was about(31.3 nm.)A high permeation rate of(32.238±1.13)μg/cm~(2)·h was showed in vitro.Ail the enhancers showed significant enhancement effect on the transdermal behavior of sinomenine microemulsion.2% borneol had the strongest effect in all. CONCLUSION: These results indicate that the studied microemulsion system with high permeation rate may be a promising vehicle for the transdermal delivery of sinomenine.Menthol,borneol and isopropyl myristate were found to be the proper penetration enhancers in the transdermal preparation.