Validation of uv derivative spectrophotometric method for determination of benazepril hydrochloride in tablets and evaluation of its stability.

The absorbance and first-, second- and third-order derivative UV spectroscopic methods were applied for the determination of benazepril hydrochloride (BEN) in model solutions and tablets, as well as the estimation of its stability in solid phase. Derivative UV spectroscopy and HPLC methods were tested for: precision, linearity, accuracy and repeatability. HPLC was used as a reference method. The study presents that derivative UV spectroscopy (the first and second derivative only) and HPLC can be successfully applied for the quantitative analysis of benazepril hydrochloride both pure and in pharmaceutical formulations. Although, the first and second derivative spectrophotometric methods are fast, precise and accurate, but they cannot be used for evaluation of purity and stability of BEN in pharmaceutical formulations (due to a lack of selectivity).