SPECTROPHOTOMETRIC METHOD DEVELOPMENT AND VALIDATION FOR VALACYCLOVIR HYDROCHLORIDE MONOHYDRATE AND RITONAVIR IN BULK AND TABLET DOSAGE FORM USING ABSORPTION RATIO METHOD

A simple, economic and accurate absorption ratio method was developed for the simultaneous estimation of valacyclovir (VC) hydrochloride monohydrate and ritonavir (RT) in bulk and tablet dosage form. 0.1M hydrochloric acid (HCl) was used as a diluent to dissolve VC and RT. One percent sodium lauryl sulphate (SLS) was used to enhance the solubility of the drugs in 0.1M HCl. The absorptions were observed at 237.52 nm and 256.75 nm, which were selected based on overlapping spectra of VC and RT. The linearity range was found to be 10–20 g/mL at 237.52 nm (r2=0.995) and 256.75 nm (r2=0.994). The method was found to be simple, precise, accurate and rapid for the simultaneous determination of VC and RT in bulk and tablet dosage form using absorption ratio method.