A Comprehensive Review of Analytical Techniques for Quantifying Cyclin‐dependent Kinase 4 and 6 Inhibitors in Biological Samples, Bulk, and Pharmaceutical Samples

Abstract

Cyclin‐dependent kinase 4 and 6 (CDK4/6) inhibitors are utilized as a remedy for advanced hormone receptor‐positive, HER2‐negative breast cancer (BC). By targeting CDK4/6, these drugs inhibit the phosphorylation of the retinoblastoma protein during the early G1 phase, leading to cell cycle arrest, disruption of deoxyribonucleic acid replication, and effective suppression of cancer cell proliferation. Recently, there has been an increasing focus on the advancement of analytical techniques for the determination of CDK4/6 inhibitors. These analytical methods are essential in the enhancement and refinement of CDK4/6 inhibitors for the management of advanced BC. This review provides a comprehensive overview of the various analytical techniques used for the analysis of palbociclib, ribociclib, and abemaciclib, along with their metabolites in biological fluids (such as blood and urine samples), commercial products, Ringer's solution, and simultaneous estimation. High‐performance liquid chromatography and liquid chromatography‐mass spectrometry are the primary analytical techniques commonly employed for the analysis of CDK4/6 inhibitors. This analytical review also provides insights into pharmacokinetics and stability studies, as well as the use of analytical techniques in detecting impurities and determining the structure of degraded products.