Development of Ion- pair Extractive Spectrophotometry Method for the determination of Ranolazine in Pharmaceutical Dosage Forms

A validated ion-pair extractive spectrophotometry method was developed for the quantitative determination of ranolazine in bulk drug and tablet dosage forms. These methods are based on stable colored ion-pair spectrophotometric method between Ranolazine and acidic dyes in acidic medium, followed by extraction into chloroform. The absorbance of the extracted chromogen was measured at 418nm respectively. The proposed methods were validated statistically. Recoveries of methods were carried out by standard addition methods. For the Bromophenol green dyes, the calibration curve showed good linearity in the concentration range of 40–90 μg/ml with a correlation coefficient (R²) of 0.995 for UV spectrophotometry measurements. Similarly for the Bromophenol blue dyes, linearity was observed in the concentration ranges of 40–90 μg/ml with R² 0.998 for UV spectrophotometry measurements indicating good linearity. The low standard deviation and % RSD values obtained for both Bromocresol green dyes and Bromophenol blue dyes indicate good repeatability and precision of this method. Both colorimetric and UV-spectrophotometry reading showed %RSD within acceptable limits, confirming the reliability of the measurements.