RESUMEN
<p><b>OBJECTIVE</b>Through the comparison of Xiaoyu ointment and xiaoyu plaster by in vitro transdermal demonstrate, to demonstrate the scientificity and feasibility of reformed formulation.</p><p><b>METHOD</b>The improved Franz diffusion cells and in vitro rabbit skin were used in vitro penetration experiment with emodin as an indicator of penetration rate quantitated by HPLC.</p><p><b>RESULT</b>The cumulative penetration rate of emodin in Xiaoyu ointment fit the model of Weibull distribution, while the cumulative penetration rate of emodin in Xiaoyu plaster fit the model of Density equation. Take emodin as an index,the transdermal rate in Xiaoyu plaster was 1.93 times as Xiaoyu ointment, and the total penetrated amount was 2.84 times as Xiaoyu ointment. The results showed that the emodin of xiaoyu plaster reserved in the skin were 3.95 times more than the ointment.</p><p><b>CONCLUSION</b>The penetration rate, total penetrated amount and the reserves in the skin of Xiaoyu plaster were better than the ointment, and the transdermal dosage form was better than the original form.</p>