Class III - low permeability, high solubility.A correlation between the bioavailability and the solvation can be found. The of those products is limited by their solvation rate.Class II - high permeability, low solubility.Those compounds are well absorbed and their absorption rate is usually higher than excretion.BCS classes According to the Biopharmaceutical Classification System (BCS) drug substances are classified to four classes upon their solubility and permeability:.
