According to the Biopharmaceutics Classification System, drug substances are classified as follows:

The substance has low solubility and low permeability under the Biopharmaceutics Classification System.

The Biopharmaceutics Classification System: Highlights of the FDA's Draft Guidance Office of Pharmaceutical Science, Center for Drug Evaluation and Research, Food and Drug Administration.

The Biopharmaceutics Classification System are the technique used to differentiate the drugs on the basis of their solubility and permeability is a guide for predicting the intestinal drug absorption provided by the U.S. Food and Drug Administration[1].