Development and Validation of a Bioanalytical HPLC Method for Quantification of Valsartan in Human Plasma and its Application in Pharmacokinetics Studies

Simple, sensitive, accurate and validated bioanalytical liquid chromatographic procedure coupled with fluorescence detector for estimation of valsartan in presence of diclofenac as internal standard (IS) in plasma has been established. The extraction of valsartan and IS was achieved using methyl tertiary-butyl ether: ethyl acetate (2:8) mixture and the extracted samples were separated on Waters, Xterra- C18 (150 x 4.6 mm, 5 & mu;m) column with 1.0 mL/min flow rate. The detection has been performed at excitation and emission & lambda; at 255 nm and 374 nm, respectively. The elution of the analytes was achieved using acetonitrile: phosphate buffer containing 1 g/L sodium salt of 1-Hexane sulphonic acid with pH adjusted to 2.5 with orthophosphoric acid (52:48, v/v) as an eluting system. The standard curves were linear from 5.0-4000.0 ng/ mL. Method validation has been prepared as per FDA guidelines. Good extraction recoveries of 87.22 % and 99.33 % for valsartan and IS have been acquired, respectively. The achieved values of accuracy and precision were in the adequate range. The proposed procedure was conducted effectively for analysis of valsartan after a single oral administration of one tablet of Tareg tablets & REG; (80 mg valsartan) to six healthy volunteers.