Physical and Chemical Characterization of Therapeutic Substances: Application to Stability Profile and Preformulation Studies

The study focused on the physical and chemical characterization of active pharmaceutical ingredients (APIs) to assess their stability and preformulation properties. It examined the stability of five APIs, including tienoxolol, bicalutamide, finasteride, benzocaine, and cysteamine hydrochloride. The research highlighted the importance of understanding crystalline polymorphism and the formation of hydrates or solvates. For instance, tienoxolol was found to be sensitive to hydrolysis and oxidation, while cysteamine hydrochloride was hygroscopic and deliquescent in water. The study used pressure-temperature phase diagrams to explore the stability of different crystalline forms, demonstrating that stability information could be obtained through standard laboratory measurements. This approach provided valuable insights into the factors affecting the intrinsic stability of APIs, which is crucial for drug development and ensuring the quality of pharmaceuticals throughout their shelf life.