Power of the Dissolution Test in Distinguishing a Change in Dosage Form Critical Quality Attributes.

For a dissolution method to be considered relevant to in vivo performance, the dissolution data profiles should show discrimination or meaningful change when there is a change in critical material attributes (CMAs) and critical product properties (CPPs). The dissolution test has been shown repeatedly to have the power to distinguish between significant changes in active pharmaceutical ingredient (API), formulation, and process that relate to the release mechanism of the in vivo performance. Examples will be discussed in the literature where the effects of formulation, drug substance, and manufacturing variables have been measured by dissolution testing. There will be a suggested plan on how to develop and challenge a discriminating method that may be utilized for regulatory purposes. A brief review of other challenges and considerations regarding discriminatory dissolution testing is presented.

The science of USP 1 and 2 dissolution: present challenges and future relevance.

Since its inception, the dissolution test has come under increasing levels of scrutiny regarding its relevance, especially to the correlation of results to levels of drug in blood. The technique is discussed, limited to solid oral dosage forms, beginning with the scientific origins of the dissolution test, followed by a discussion of the roles of dissolution in product development, consistent batch manufacture (QC release), and stability testing. The ultimate role of dissolution testing, "to have the results correlated to in vivo results or in vivo in vitro correlation," is reviewed. The recent debate on mechanical calibration versus performance testing using USP calibrator tablets is presented, followed by a discussion of variability and hydrodynamics of USP Apparatus 1 and Apparatus 2. Finally, the future of dissolution testing is discussed in terms of new initiatives in the industry such as quality by design (QbD), process analytical technology (PAT), and design of experiments (DOE).

Addressing the Challenge of Developing a Physiologically Relevant Dissolution Test for Regulatory Purposes.

The challenge of developing a physiologically relevant dissolution test to satisfy regulatory agencies has pushed drug manufacturers to engage in "design of experiment" method development, which helps manufacturers address variability, dissolution medium, and surfactant use-all of which will influence dissolution.

Scientific and regulatory standards for assessing product performance using the similarity factor, f2.

The similarity factor, f2, measures the sameness of dissolution profiles. The following commentary is an overview of discussions and presentations from a group of industry and US regulatory experts that have integrated the science and regulatory research and practice for assessing product performance, particularly for modified-release (MR) dosage forms, using f2. For a drug development sponsor or applicant with an orally complex dosage formulation, it is critical to understand dissolution methods and the similarity factor and how and/or when to apply it in their NDA, ANDA, or PMA submission. As part of any regulatory submission, it is critical to justify that the product performance has not been impacted by any change in the manufacturing process and/or the delayed and/or prolonged drug release characteristics compared to a similar conventional or another orally complex dosage form. The purposes of this document are (1) to provide a description of appropriate dissolution methods, how is the f2 calculated and how it can be used to justify product performance similarity, or not; (2) to provide an overview of alternative methods available for dissolution profile comparisons, and (3) to illustrate how applying these concepts in a focused way supports approval of submissions and regulatory dossiers and aligns them with on-going science and regulatory initiatives. A case study will be used as an example to demonstrate how dissolution testing and the f2 calculation results can impact regulatory outcomes from an NDA (505(b)(1)), NDA (505(b)(2)), ANDA (505(j)), supplemental NDAs/ANDAs, or PMA perspective.