Derivative Spectrophotometric Methods for the Analysis and Stability Studies of Ranolazine in Bulk and Dosage Forms

Abstract

The present study was aimed to develop simple and accurate derivative spectrophotometric methods ( 1 D and 2 D) for the assay and stability studies of Ranolazine (RAN) in bulk and dosage forms. The methods were based on differentiating the original UV spectrum of RAN solution in methanol to generate the first and second derivative spectra which were measured at 278nm and 283 nm, respectively. The developed methods were then validated as per ICH guidelines and applied for the stability studies. Beer's law was found to be valid over the concentration range100-600 µg/ml with correlation coefficient (r) not less than 0.999. The obtained limit of detection (LOD) and limit of quantification (LOQ) reflected the sensitivity of the methods (24.0 µg/ ml and 73.0 µg/ ml, 17.8 µg/ ml and 53.6 µg/ ml, for 1 D and 2 D, respectively). Good results were also obtained from the assay of RAN tablets (98.6 ± 2.3%, n=3). Studying the stability behavior of RAN using the developed methods reflects its instability under alkaline conditions following the first-order kinetics. The statistical validation at a 95% confidence level proves the sensitivity, precision, accuracy, and stability-indicating properties of the developed methods.