Spectrophotometric Estimation of Rosuvastatin, Simvastatin and Olmesartan in Bulk and Dosage Forms Using Bromatometric Method

Abstract

Background: A simple and sensitive spectrophotometric method is described
for determination of rosuvastatin, simvastatin and olmesartan in bulk and dosage forms
using bromate-bromide and methyl orange as reagents.
Material and methods: Drugs are treated with known excess of insitu generated bromine
and residual un-reacted bromine is determined by treating with fixed amount of methyl
orange then measuring absorbance at 510 nm. The amount of bromine consumed
corresponds to the amount of each drug reacted. Various analytical parameters have been
evaluated such as effect of acidity, bromate-bromide volume and time on the absorption
and the results were validated according to ICH guidelines.
Results: Beer’s law was obeyed in the range of 6–11 μg/mL for rosuvastatin, 1–3.50 μg/mL
for simvastatin and 2–7 μg/mL for olmesartan.
Conclusions: The method was satisfactory applied for the determination of drugs in both
bulk and pharmaceutical forms and results were compared statistically with reference
methods.