The US Food and Drug Administration (FDA) has issued draft guidance, Dissolution Testing and Specification Criteria for Immediate-Release Solid Oral Dosage Forms Containing Biopharmaceutics Classification System Class 1 and 3 Drugs, to provide manufacturers with recommendations for submission of
new drug applications, investigational new drug applications, and/or abbreviated new drug applications, as appropriate, for immediate-release (IR) tablets and capsules that contain highly soluble drug substances.
The draft guidance is intended to describe when a standard release test and criteria may be used in lieu of extensive method development and specification-setting exercises. When final, this guidance will supersede the guidance for industry on Dissolution Testing of Immediate Release Solid Oral Dosage Forms , which was issued in August 1997, for Biopharmaceutics Classification System (BCS) Class 1 and 3 drug substances in immediate-release drug products that meet the criteria in this guidance. For class 2 and 4 drug substances, applicants should still refer to the August 1997 guidance.
The BCS is a scientific framework for classifying drug substances based on their aqueous solubility and intestinal permeability. The definitions of high and low solubility and high and low permeability are described in the Biopharmaceutics Classification System (BCS). The different classifications are: Class 1: High Solubility - High Permeability Drugs; Class 2: Low Solubility - High Permeability Drugs; Class 3: High Solubility - Low Permeability Drugs; and Class 4: Low Solubility Low Permeability Drugs.
This classification can be used as a basis for determining when in vivo bioavailability and bioequivalence studies are needed and can be used to determine when a successful in vitro-in vivo correlation is likely. The BCS suggests that, for certain high solubility drugs, dissolution testing can be standardized. Owing to their high solubility, BCS Class 1 and 3 drugs are considered to be relatively low risk regarding the impact of dissolution on performance, provided the in vitro performance meets or exceeds the recommendations discussed in the guidance.