Development and Validation of RP-HPLC Method for Simultaneous Estimation of Dorzolamide and Natarsudil Dimesylate in Pharmaceutical Formulations

Abstract

Dorzolamide hydrochloride and Natarsudil is a well-established fixed-dose combination for the treatment of glaucoma worldwide. The study focuses on validating and developing a precise, simple, and accurate stability-indicating RP-HPLC method for simultaneously estimating Dorzolamide and Natarsudil in pharmaceutical formulations. The chromatographic separation was achieved by using a Chomosil C₁₈ column (250 × 4.5 mm, 5 μm) with acetonitrile: methanol: 0.01N Ammonium acetate buffer in a ratio of 45:35:20 v/v as a mobile phase at a constant flow rate of about 1.0 mL/min. The development and validation were carried out at a detection wavelength of 242 nm. We developed a robust RP-HPLC method, validated for linearity, precision, accuracy, specificity, and system suitability. The method demonstrated excellent linearity with correlation coefficient values r² was nearly 0.9989 and 0.9985 respectively with a linearity range 2.5-30 μg/mL for Dorzolamide and 2.5-30 μg/mL for Natarasudil. LOD and LOQ were found to be lower; hence, the method is sensitive. Percentage recovery was obtained at 99.97% and 99.99% for Dorzolamide and Natarasudil, respectively. In the case of precision, robustness and repeatability, RSD was found to be less than 2. The validated and developed RP-HPLC method offers an efficient and practical approach for simultaneously quantifying Dorzolamide and Natarsudil in pharmaceutical formulations, making it a valuable tool for quality control and pharmaceutical research.