Development of PBBM Framework to Support an Assessment of Bioequivalence for Locally-Acting Drugs in the Gastrointestinal Tract in Healthy Subjects and Patients

University Of Bath, Bath

Investigators

Abstract

Development of PBBM Framework to Support an Assessment of Bioequivalence for Locally-Acting Drugs in the Gastrointestinal Tract in Healthy Subjects and Patients – Project Summary The goal of this project is to propose a new, validated model-integrated approach as an alternative to comparative clinical endpoint bioequivalence (BE) studies when evaluating the BE of locally acting drug products in the gastrointestinal tract (GIT). This goal will be achieved through two paired elements: an in vitro component and an in silico component. In vitro dissolution of GIT locally acting drug products currently approved on the market will be measured in biorelevant dissolution media representing the healthy and diseased gut physiology. Additionally, formulation variants will be created for three (3) APIs. Their dissolution properties will be tested in the same in vitro assays. This effort will provide a first indication of the impact of product quality attributes on API dissolution/release in patients. In parallel, the Advanced Compartmental Absorption and Transit (ACAT™) model, within GastroPlus© physiologically based pharmacokinetic (PBPK) platform, will be adapted to account for GIT disease conditions. Combining the in vitro dissolution results from currently approved GIT locally acting drug products with the enhanced ACAT model, in vitro to in vivo relationships will be established to assess the ability of the PBPK model to predict local and systemic exposures. Parameter sensitivity analysis (PSA) will be performed to differentiate the relative importance of product quality attributes and pathophysiological parameters on the local and systemic concentration time courses. Finally, a virtual BE approach will be used to compare the test formulation variants with their respective references. Respective PK metrics at the site of action and in plasma for the test and reference drug products will be compared to assess BE in both biophases. The findings from this project will support the regulatory assessment of locally acting drug products for GIT diseases by proposing a novel, model-integrated approach in lieu of the current BE practices. This methodology will help to establish scientific and regulatory standards for supporting innovative development and performing BE evaluation of these complex generic drug products.