Objective: To optimize preparation process of sinomenine hydrochloride-loaded self-dissolving microneedles and to investigate effect of microneedles on transdermal delivery of sinomenine hydrochloride. Method: The microneedles was prepared by casting method.Taking formability and mechanical property of micrneedles as indexes

prescription with optimal drug content was screened out

and its characterization was investigated.In vitro permeation of sinomenine hydrochloride-loaded self-dissolving microneedles and sinomenine hydrochloride-loaded hydrogel were examined by Franz diffusion cell.HPLC was employed to determine the content of sinomenine hydrochloride with mobile phase of methanol-0.1% phosphate solution (18: 82) and detection wavelength of 263 nm. Result: Optimal prescription was as follows:polyvinylpyrrolidone (PVP) of 50%

chondroitin sulfate of 15%

sinomenine hydrochloride of 35%.The developed microneedles had regular shapes of needles with good mechanical strength

it can insert into aluminum foil and rat's skin.Accumulation permeation amount and rate of sinomenine hydrochloride in microneedles group increased 5.31 times and 5.06 times versus hydrogel group

respectively. Conclusion: These prepared microneedles have ideal formability and mechanical property.It provides more effective permeability of sinomenine hydrochloride by comparing with hydrogel group.