A simple thin layer chromatography ultraviolet densitometric method has been established for the separation and quantitative determination of Puerarin in plasma. Using ethyl acetate : metha-nol: water : toluene : absolute alcohol ( 100 : 15.5: 13.5: 2 :13.5 V/V ) as the developing system, 5?l supernatant of the sample extracts were spotted on high performance sillica gel G glass plates and developed. The separeted spots were scanned using Shimadzu CS-910 TLC scanner, the results were calculated by the areas of spots with Rf 0.47. The mininum detectable quantity of Puerarin was 7.5ng/spot. The plasma concentration-time curve of Puerarin in rabbits after single iv 30mg/kg was best fitted to a two- compartments open model. The T1/2? , T1/2? (3 were 5.7, 27.5 min respectively. This showed that Puerarin is distributed and eliminated in a fairly rapid rate in rabbits.

Purpose To prepare the sustained-release tablet of tetramethylpyrazine phosphate with hydroxypropylmethylcelluose(HPMC) as matrix material. MethodsThe paddle method and the HPLC method were erspectively used determined the cumulative drug released in vitro and the serum concentration in vivo.ResultsThe cumulative drug released in the first hour was about 20%, while in 12 hours it was above 85%. Drug release behavior can be best described by Higuchi equation, and the release rate decreased as the viscosity and/or the amount of HPMC increased. Compared with the market tablet on the rabbits, the sustained release tablet had the decreased peak concentration (P < 0.05 ); the prolonged peak time and mean residence time (P< 0.05).ConclusionsThe matrix tablet was a good sustained-release dosage form and it had a good in vitro-in vivo correlation.