Abstract: This literature review focuses on the evaluation of active pharmaceutical ingredient (API) stability in expired and unexpired tablet formulations of Albendazole, Azithromycin, and Paracetamol using High Performance Liquid Chromatography (HPLC). The objective of such studies is to assess changes in drug potency, chemical stability, and therapeutic effectiveness following the expiration period. Existing findings indicate that unexpired tablet formulations consistently comply with pharmacopeial standards, maintaining API concentrations within the acceptable range of 90–110%. In contrast, expired formulations exhibit a gradual decline in API content, suggesting ongoing chemical degradation. Among the drugs evaluated, Paracetamol demonstrates comparatively higher stability, with minimal reduction in potency beyond its expiration date. Conversely, Azithromycin and Albendazole show greater susceptibility to degradation, likely due to environmental influences such as temperature, humidity, and light exposure.HPLC is recognized as a reliable and precise analytical technique for the quantification of APIs and detection of degradation products. Overall, the reviewed evidence highlights the critical importance of expiration dates in ensuring drug safety and efficacy. Additionally, it contributes to a broader understanding of degradation patterns in commonly used pharmaceuticals and supports regulatory guidelines for proper storage and usage.