SIMULTANEOUS ESTIMATION OF IVACAFTOR AND TEZACAFTOR IN RAT PLASMA BY LC-MS-MS: APPLICATION TO PHARMACOKINETIC STUDIES:TJPS-2021-0144.R2

Abstract

Background: Ivacaftor and Tezacaftor belong to the C.F.T.R potentiator class, in combination approved to manage cystic fibrosis. Objective: To establish a sensitive LC-MS-MS approach for the synchronized analysis of ivacaftor and tezacaftor and its appliance to rat pharmacokinetic investigation. Methodology: Method is developed with protein precipitation by acetonitrile and ivacaftor-d4, tezacaftor-d4 are used as internal standards. Separation is done on an Eclipse plus C18 analysis column (100 mm × 4.6 mm 1.8 µm) with a mobile phase consisting of 0.1% trifluoroacetic acid: acetonitrile (ratio 60:40, v/v, and pH 2.5) and flow stream of 1.0 mL/min at ambient temperature. Results: The approach developed showed a fine calibration curve in the quantity range of 1.5 - 22.53 ng/mL (r2 – 0.99974) for ivacaftor and 1 - 15.02 ng/mL (r2 – 0.99988) for tezacaftor and the accuracy and precision meets F.D.A Guidelines. 
Conclusion: The newly designed and validated approach was simple, fast, and applied effectively for rat pharmacokinetic investigation.