A Simple and Rapid HPLC Method Development for Quantification of Sodium Benzoate Content in Chlorzoxazone Oral Solid Dosage Forms.

The present study discusses the development of a simple, rapid, and specific HPLC method for the estimation of sodium benzoate in chlorzoxazone tablet dosage formulations. The current developed HPLC method was validated as per the current ICH guidelines. The chromatographic separation was achieved using a 0.02-M phosphate buffer adjusted to pH 3.0 with orthophosphoric acid as the buffer. Mobile phase A consisted of 100% buffer, and mobile phase B was a mixture of acetonitrile and buffer in a ratio of 80:20 (v/v). The column temperature was maintained at 30°C, the sample cooler at 25°C, and the flowrate at 0.8 mL min^-1. The injection volume was 10 μL. The UV detection was performed at 230 nm for Sodium benzoate. The validated HPLC method was highly specific, with linearity ranging between 1.2 and 7.5 μg/mL for sodium benzoate, and the correlation coefficient was found to be > 0.999. The method showed high accuracy, exceeding 97%. The results demonstrate the successful applicability of the current method for the estimation of sodium benzoate in marketed formulations, which can be extended to assess other formulation systems. The developed method was validated as per international ICH guidelines with respect to specificity, linearity, precision, accuracy, and robustness. The method was applied to the analysis of stability samples.