Regulatory Experience with In Vivo In Vitro Correlations (IVIVC) in New Drug Applications.

In the past two decades, in vitro in vivo correlation (IVIVC) has been considered an important tool for supporting biowaivers, setting dissolution acceptance criteria, and more recently in the Quality by Design (QbD) framework promoting the establishment of clinically meaningful drug product specifications using dissolution as the endpoint. Based on our review experience at the FDA, for the purposes of this article, we analyzed the current state of regulatory submissions containing IVIVC approaches and discussed the successes and failures from the perspectives of study design to methodology. In the past decade, the overall acceptance rate of the IVIVC submissions is about 40%. Moreover, the number of IVIVC studies seen in the submissions per year is not increasing. Establishing clinically meaningful drug product specifications through the linkages between the identified critical quality attributes and in vivo performance is key for developing a quality drug product. To achieve this goal, there is an imminent need for addressing the issues behind a low success rate in IVIVC development. The results from the current analysis revealed that special considerations should be taken in areas such as (1) selection of appropriate number/kind of formulations for IVIVC development/validation, (2) construction of exploratory plots to guide model building and selection, (3) investigation of the reasons of inconclusive predictability, (4) improvement on the quality and richness of the data, and (5) avoidance of over parameterization. The development and incorporation of biopredictive dissolution methods and the use of non-conventional approaches, including mechanistic/physiologically based approaches, should be explored to increase the likelihood of IVIVC success.