solubility

Solubility and Distribution Phenomena
Solubility is defined the maximum solute concentration in a certain solvent at a certain temperature, and in a qualitative way, it can be defined as the spontaneous interaction of two or more substances to form a homogeneous molecular dispersion.
A saturated solution is one in which the solute in solution is in equilibrium with the solid Phase.
unsaturated or subsaturated solution is one containing the dissolved solute in a concentration below that necessary for complete saturation at a definite temperature.
supersaturated solution is one that contains more of the dissolved solute than it would normally contain at a definite temperature, were the undissolved solute present.
The solubility of a compound depends on
• the Physical and chemical properties of the solute and the solvent
• temperature.
• Pressure.
• PH of the solution
thermodynamic solubility of a drug in a solvent is the maximum amount of the most stable crystalline form that remains in solution in a given volume of the solvent at a given temperature and pressure under equilibrium conditions. The equilibrium involves a balance of the energy of three interactions against each other:
(1) solvent with solvent,
(2) solute with solute
(3) solvent and solute