DEVELOPMENT AND VALIDATION OF A RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF VANZACAFTOR, TEZACAFTOR, AND DEUTIVACAFTOR IN PHARMACEUTICAL FORMULATION

The present study reports the development and validation of a simple, precise, and robust RP- HPLC method for the simultaneous estimation of Vanzacaftor (VNC), Deutivacaftor (DEC), and Tezacaftor (TZC) in the fixed-dose combination formulation Alyftrek. Chromatographic separation was achieved using an XTERRAC18 column (250×4.6mm, 5µm) with a mobile phase consisting of potassium dihydrogen phosphate buffer and methanol (80:20, v/v). The analytes were detected at 247nm, and well-resolved peaks were obtained at retention times of 3.206 min (VNC), 5.148 min (DEC), and 6.823 min (TZC). The method was validated according to ICHQ2 (R1) guidelines. Linearity was established over the ranges of 2–6 µg/mL for VNC, 25–75µg/mL for DEC, and 10–30µg/mL for TZC with correlation coefficients (R²) close to 1. The limits of detection were 0.045 µg/mL (VNC), 0.431 µg/mL (DEC), and 0.073 µg/mL (TZC), while the limits of quantification were 0.150 µg/mL, 1.436 µg/mL, and 0.245 µg/mL, respectively. Precision studies showed %RSD values below 1%, indicating excellent repeatability. Accuracy was confirmed with recovery values between 99–100% for all three drugs. Overall, the method demonstrated suitability for routine quality control analysis, offering accurate quantification and reliable performance for simultaneous estimation of VNC, DEC, and TZC in pharmaceutical formulations.