Development and Validation of a UV Spectrophotometric Method for Estimation of Ritonavir in Bulk Drug Form

Abstract

Ritonavir is a protease inhibitor, an anti-retroviral medication used along with other medications to treat HIV/AIDS. Ritonavir is also used for the treatment of anti-viral infections. The study aimed to develop and validate a UV spectrophotometric method for the estimation of Ritonavir in bulk drug form. By dissolving ritonavir in non-aqueous solvents such as ethanol and adding distilled water to reach volume, absorbance was achieved using this procedure. As a result, Methanol was used as a blank sample while estimating ritonavir. To determine the analytical wavelength, a 10µg/ml Ritonavir solution was prepared in a 100ml volumetric flask by diluting 1ml of working standard solution with methanol: water. The method’s performance was statistically validated for key parameters. A quick and affordable UV spectroscopy method has been created using methanol as a solvent for the validation of ritonavir in bulk dosage form. Ritonavir’s absorption peak was observed at 240nm using methanol as solvent. This method obeys Beer's law and concentration ranges from 5µg/ml - 100µg/ml for ritonavir. The method was validated according to Regulatory standards for pharmaceuticals, demonstrating linearity for ritonavir across 5-100µg/ml with a regression coefficient of 0.9613. The method accuracy was resolved by a recovery study. The amount of drug recovered was found to be in the range of 98.7 – 99.8 %. The developed method showed good precision (%RSD≤ 2) and sensitivity (LOD: 0.314, LOQ:0.952). Residual plots (absorbance deviations from the regression line) indicated that deviations increase slightly at concentrations ˃80 µg/ml. This could arise from Minor deviations from Beer-Lambert’s law due to high analyte absorbance and detector saturation at higher optical densities. The validation results indicate that the method is accurate, precise, simple, and economical, making it suitable for routine analysis of Ritonavir in bulk dosage form. The developed method can be effectively applied in quality control laboratories. Hence, it can be recommended for regular estimation of Ritonavir, and the study confirms the effectiveness of UV spectrophotometry for Ritonavir Analysis.