In August 2015, the FDA published the draft of a guideline on dissolution testing for immediate release solid oral dosage forms. It is planned that after its finalisation, a part of this guideline will replace the current guideline from August 1997.
The Biopharmaceutics Classification System (BCS) distinguishes 4 different classes of APIs depending on their solubility and permeability.
On the basis of this classification, a decision can be taken for determining when bioavailability or bioequivalence studies are required, or when a successful in vitro-in vivo correlation (IVIVC) is likely.
The BCS proposes that, for certain medicinal products which contain a high soluble API, dissolution testing can be standardised. Due to their high solubility, medicinal products in the BCS classes 1 and 3 have a relatively low risk with regard to the impact on dissolution, provided that the in vitro performance meets or exceeds the recommendations given.
If these conditions are met, the new guideline will provide concrete provisions regarding the methods which can be standardised: USP apparatus 1 (basket method) or 2 (paddle method) with fixed parameters for stirring rate, medium and temperature. For this, the permitted limits for the specifications are laid down. In addition, the possibility is granted that, under certain conditions, disintegration testing can be used as alternative method.
You can access the complete document of the FDA "Dissolution Testing and Specification Criteria for Immediate Release Solid Oral Dosage Forms" here.