Separation, Identification and Characterisation of Acidic Degradation of Ritonavir Under ICH Recommended Stress Condition by HPTLC, MS/TOF

Abstract

The current study reports the characterization of degradation product from Ritonavir (RITO) through mass spectrometry and the development of a validated and stability-indicating High performance thin layer chromatographic method for the determination of RITO in the presence of its process-related degradation in bulk drug. Stability study on Ritonavir (RITO) was carried out under hydrolytic condition in acidic, alkaline and peroxide, thermal and photolytic conditions in accordance with International Conference on Harmonization (ICH) guidelines Q1 (R2). The drug was found susceptible for degradation under acidic conditions while in rest of conditions drug were stable. A degradation product (DP) was formed in acidic condition. Chromatographic separation was performed on precoated silica gel 60F254 HPTLC plates using acetonitrile: methanol: water (5:3.5:2.5 v/v) as a mobile phase. A mixture of stressed samples was subjected for IR and MS/TOF studies to obtain functional group and mass spectral data. The data found from precise mass study was first utilized to pattern a complete mass fragmentation pathway of the drug and later it was used for its degradant. Structures were proposed for each fragments based on best possible molecular formula. Acidic degradation of RITO 3((3S, 4R)-3-isopropyl-4-(((S)-2-((methoxycarbonyl) amino)-3-phenylpropyl) amino)-2-oxo-5-phenylpentyl)-1-((2isopropylthiazol-4-yl) methyl)-1-methyluronium was identified.