UV Spectrophotometric Method Development and Validation for Simultaneous Determination of Flunarizine Dihydrochloride and Propranolol Hydrochloride in Combined Capsule Dosage form

A simple, sensitive, accurate and precise UV ‐ spectrophotometric isobestic point method for simultaneous estimation of flunarizine dihydrochloride and propranolol HCl in capsule dosage form has been developed and validated for accuracy, precision, ruggedness, linearity and range. The wavelengths selected for estimation of drugs were 262.5 nm (isobestic point at which both drug exhibit equal absorbance) and 288.8 nm (&#955; <SUB>max</SUB> of propranolol hydrochloride). Linearity for detector response for flunarizine dihydrochloride and propranolol HCL were 1-25 &#181;g/ml and 4-100 μg/ml respectively. The method gives results for high accuracy and high recovery of 99.76±0.08 and 99.38±0.22 for flunarizine dihydrochloride and propranolol HCL respectively. % R.S.D. Values for marketed formulation analysis were found to be less than 2 which indicated good precision and reproducibility of the method. The method was found to be simple, sensitive, accurate and precise.