Solubility Definition: Solubility is generally expressed as the maximum amount of solute that dissolves in a given volume of solvent. As water is the most used solvent in pharmacy and biological fluids are aqueous solutions,we will focus on solubility in water. Saturated Solution: A solution where the dissolved solute is in equilibrium with the undissolved solute( the solid phase) Solubility(Cs上z The concentration of a solute in saturated solution at a given temperature and pressureSolubility Definition: Solubility is generally expressed as the maximum amount of solute that dissolves in a given volume of solvent. As water is the most used solvent in pharmacy and biological fluids are aqueous solutions, we will focus on solubility in water. Saturated Solution: A solution where the dissolved solute is in equilibrium with the undissolved solute( the solid phase) Solubility(Cs): The concentration of a solute in saturated solution at a given temperature and pressure