Comprehensive Review on Analytical Methods for Retinol and Retinoids

Retinol and retinoids, which are critical for pharmaceutical, cosmetic, and nutraceutical applications, exhibit photolability and oxidative instability, necessitating the development of robust analytical methods. High-performance liquid chromatography (HPLC) coupled with UV/DAD, fluorescence (FLD), and mass spectrometry (MS) dominates quantification across matrices, including plasma, cosmetics, and formulations, achieving LODs from20 pg/mL to 0.34 μg/mL. This review critically analyzes extraction strategies (SPE, enzymatic digestion), validationper ICH Q2(R1), stability-indicating assays monitoring cis-isomerization and photodegradation, and emergingtechniques such as paper spray MS and multidimensional fluorescence. Comparative performance metricshighlighted the superiority of LC-MS/MS for trace analysis (recoveries 89-94%), while green HPLC was suitable forroutine quality control. Challenges related to matrix interference and light protection are addressed, providingpharmaceutical scientists with method selection guidelines for regulatory compliance and stability studies. Thismanuscript synthesizes peer-reviewed studies to provide evidence-based recommendations for the analysis ofretinoids across diverse applications.