Stability indicating LC Method Development and Validation for the Simultaneous analysis of Cystic Fibrosis Drugs-Ivacaftor and Tezacaftor in Pharmaceutical Formulations

Ivacaftor and Tezacaftor are the combined medication prescribed for the treatment of cystic fibrosis mutation. A simple and accurate stability indicating HPLC method was developed for separation and simultaneous analysis of Ivacaftor and Tezacaftor. The method utilizes a mobile phase composition of ammonium acetate buffer (pH 5.0) and acetonitrile in the ratio of 60: 40 (v/v) as mobile phase at a flow rate of 1.0 mL/min and the separation of Ivacaftor and Tezacaftor was achieved on Sunfire C18 column (150mm×4.6mm; 3.5μ id) and the column eluents were recorded using UV detector at a wavelength of 260 nm. In these conditions, Ivacaftor and Tezacaftor elutes at a retention time of 1.8 min and 3.5 min respectively with a shortest run time of 5 min. The calibration curve was observed within the concentration range of 50–150 μg/mL for TZCF and 75–225 μg/mL IVCF with a correlation of more than 0.999 for both the drugs. The method was found to be precise, accurate and robust and is enough sensitive for the analysis of Ivacaftor and Tezacaftor. The forced degradation study confirms that Ivacaftor and Tezacaftor were found to be stable in the stress conditions and can effectively separate the degradation compounds. Hence the method can be suitably applicable for the routine analysis of Ivacaftor and Tezacaftor in formulation and stability studies.