Solubility of Drugs Physical Pharmacy PDF Note Free Download For Pharmacy Students. Solubility expressions, mechanisms of solute solvent interactions,ideal solubility parameters, solvation & association, quantitative approach to the factors influencing solubility of drugs, diffusion principles in biological systems. Solubility of gas in liquids, solubility of liquids in liquids, (Binary solutions, ideal solutions) Raoult’s law, real solutions. Partially miscible liquids, Critical solution temperature and applications. Distribution law, its limitations and applications.