Advances in Solubility Enhancement of Poorly Soluble Drugs in Pharmaceutical Development: A Review of Current Techniques and Strategies

Solubility is a key determinant in the bioavailability of drugs, particularly those categorized under Class II and IV of the Biopharmaceutical Classification System (BCS), which exhibit poor aqueous solubility. This review provides an introduction to the concept of solubility, alongside a brief discussion on the BCS classification. Key definitions of solubility are presented, followed by a mention of several factors affecting solubility, such as temperature, pH, and particle size. The article then outlines various techniques employed to enhance solubility, including physical methods like particle size reduction and solid dispersions, as well as chemical strategies such as salt formation and co-crystallization. These approaches are crucial for improving drug absorption and formulation development. This review offers an overview of current solubility enhancement techniques, contributing to the advancement of pharmaceutical science and drug delivery systems.