Determination Of Valsartan And Hydrochlorothazid In Valsartan And Hydrochlorothiazid Capsules By HPLC And Valsartan Preliminary Application In Pharmacokinetic

ObjectiveTo establish an HPLC method for simultaneous determination of Valsartanand Hydrochlorothiazid in Valsartan and Hydrochlorothiazid Capsules. Themeasurement uncertainties of the HPLC method for determination of Valsartanand Hydrochlorothiazid Capsules was evaluated. A method was applied todetermine the concentration of valsartan in rabbit plasma, and was applied to apreliminary pharmacokinetic research for valsartan in rabbit plasma.MethodsHPLC method for simultaneous determinations of Valsartan and Hydrochl-orothiazid in Valsartan and Hydrochlorothiazid Capsules: The determinationwas performed by HPLC using an Chromatrex C18(200mm×4.6mm,5μm)column with column temperature at25℃. The mobile phase consisted ofmethanol-water (70:30) with the pH adjusted to3.1with phosphoric acid at aflow rate of1mL/min.The detection wavelength of230nm. An evaluate methodfor uncertainty of simultaneous determinations of Valsartan and Hydrochloroth-iazid in Valsartan and Hydrochlorothiazid Capsules by HPLC: The model forevaluation of the uncertainty was established based on the measure of contentof Valsartan and Hydrochlorothiazid Capsules by HPLC. The factors influenced on the measuration were analysed. The plasma samples concertrations atdifferent times for the rabbits were assayed by high performance liquidchromatography(HPLC). And the parameters of pharmacokineties werecalculated with DAS2.1.1pharmacokinetic program.ResultsThe calibration curve for valsartan was linear in the concentration range of8~160μg/mL with r=0.9997.The average recovery was99.29%and RSD=0.72%.And the calibration curve for hydrochlorothiazid was linear in theconcentration rang of1.25~25μg/mL with r=0.9995. The average recovery was100.21%and RSD=1.84%. The pharmacokinetic profiles obeyed a two-compartment model after taking drug,pharmacokinetic parameters: t （α）=4.402ht﹙β﹚=4.208h,Tmax=2.5h,Cmax=1.833mg/L,AUC(0-5)=13.233(mg/L)·h.ConclusionsThe method have a good sensitivity,reproducibility and specificity and canbe used in analyzing in vivo and vitro. The study of valsartan will have referencevalue in vivo future research. And prarmacokinetic study of the concentration-time curve drawn to guide clinical use of drugs.