Topic overview

Start with the big picture

Drug molecules can degrade through several pathways, including hydrolysis, oxidation, photolysis, racemization, decarboxylation, and isomerization. Susceptibility depends on features such as reactive functional groups, chirality, and solid-state form, as well as conditions including moisture, pH, light, temperature, and catalytic ions. Formulation and packaging approaches—such as pH adjustment, antioxidants, chelators, light protection, and lyophilization—can help limit degradation. Reaction kinetics connect degradation behavior to shelf-life assessment, while stress testing and forced-degradation studies help identify degradation products and support stability-indicating analytical methods. Together, these concepts link molecular reactivity with practical decisions in formulation, storage, and stability evaluation.