Determination and quantification of related substances and degradation products in bictegravir by full factorial design evaluated HPLC and mass spectrometry.

Determining and quantifying novel impurities and degraded impurities of a drug product is always a continuous challenge to enhancing the drug quality for patients' safety. Herein, our work deals with (i) developing a rapid, accurate, and reliable high-performance liquid chromatographic validation method to quantify the bictegravir drug (integrase inhibitors of antiretroviral drugs) and its novel related impurities at low levels, and (ii) the liquid chromatography-mass spectrometry (LC-MS) method to identify degraded impurities. Separation of bictegravir acid (impurity-I) and methyl bictegravir (impurity-II) impurities which are identified by LC-MS in the bictegravir drug was executed by developing a method and the same method performance evaluated by using full factorial design. This developed analytical technique gave a well-separated peak of bictegravir and related analytes such as bictegravir acid (impurity-I) and methyl bictegravir (impurity-II), adequate with the peak properties as per USP guidelines. The method's sensitivity and linearity are demonstrated by its detection and quantification limits at low levels with a correlation coefficient of 0.998. The method's repeatability, specificity, and accuracy suggest that this developed technique is a reliable determination strategy for the bictegravir drug substance and its related impurities (impurity-I and impurity-II) in a simple, feasible, and affordable way.