Objective: To optimize matrix formulation of Jiufen cataplasms and investigate its in vitro release characteristics. Method: With viscosity and in vitro release constant of Jiufen cataplasms as indexes

effects of dosage of carbopol

CMC-Na

sodium polyacrylate

polyvinyl alcohol and glycerol on quality of Jiufen cataplasms were investigated by uniform design

multiple regression of test data was analyzed by Excel

then optimized matrix formulation of Jiufen cataplasms and determined its in vitro release.The content of strychnine was determined by HPLC

chromatographic conditions were as follows:Hypersil BDS C18 column(4.6 mm×250 mm

5 μm)

mobile phase of methanol-water-triethylamine-glacial acetic acid(20:280:0.3:2.4

pH 4.5)

flow rate l mL·min-1

detection wavelength 254 nm. Result: The best matrix formulation of Jiufen cataplasms was:carbopol-polyacrylate sodium-polyvinyl alcohol-sodium carboxymethylcellulose-glycerol(1:1:1:1.75:20).In vitro release properties of Jiufen cataplasms conformed to Higuchi equation with R2 of 0.902 4. Conclusion: Jiufen cataplasms had good forming

it could maintenance in vitro release for 24 h.Method combining Excel software and uniform design was simple and feasible.