RP-HPLC Stability Indicating Analytical Method Development and Validation For The Simultaneous Estimation Of Tezacaftor, Ivacaftor and Elexacaftor In API and Pharmaceutical Dosage Form

We developed a straightforward, precise method for the simultaneous estimation of Ivacaftor, Elexacaftor and Tezacaftor in both bulk and tablet dosage forms. The chromatography analysis was performed using a Discovery C18 column measuring 150 x 4.6 mm with a 5µm particle size. The mobile phase, composed of Acetonitrile: Methanol: 0.1% OPA (10:35:55 v/v) was pumped at a flow rate of 0.9 ml/min, with the temperature maintained at 28°C. The optimized wavelength for detecting 3 drugs was set at 278.0 nm. Retention times were measured at 2.537 min, 2.089 min, and 3.090 min, respectively. The method precision showed low %RSD values, with 0.4 for Ivacaftor, 0.3 for Elexacaftor and 0.4 for Tezacaftor. Recovery percentages were determined as 99.79% for Ivacaftor, 99.72% for Elexacaftor and 100.05% for Tezacaftor. Furthermore, the LOD and LOQ values derived from the regression equations for  Ivacaftor, Elexacaftor and Tezacaftor i.e  y = 22674x + 2799.3, y = 21285x + 4513.2 and y = 21548x + 869.63  were found to be 0.06 ppm and 0.22 ppm, 0.18 ppm and 0.19 ppm , 0.07 ppm and 0.57 ppm  respectively. With reduced retention times, this method offers simplicity and cost-effectiveness, making it suitable for routine quality control testing.