Application of Physiologically Based Biopharmaceutics Modeling (PBBM) to Establish Clinically Relevant Dissolution Specifications for a Prolonged Release Tablet Formulation of Verapamil, a BCS Class I Drug.

Our work aimed at setting clinically relevant dissolution specifications for a prolonged release formulation of verapamil, a BCS Class I drug. We have used a two-pronged approach- a Level A IVIVC correlation supplemented with virtual bioequivalence assessment using Physiologically based biopharmaceutics modelling (PBBM). Dissolution studies were performed for two batches, Medium-release (BE batch) and Slow-release (non-BE batch), using a biorelevant method. Mechanistic absorption deconvolution method was used to obtain the in vivo release profiles and correlate with the respective in vitro release profiles to develop the IVIVC. Theoretical dissolution profiles for upper and lower limits were generated and used for convolution and calculation of Percent prediction errors (%PE). This was supplemented with virtual bioequivalence (VBE) assessments at each level to select clinically relevant dissolution specifications. A two-step deconvolution-correlation method resulted in a linear Level A IVIVC with R² = 0.951 which was internally and externally validated. Percent prediction errors (%PE) for C_max and AUC were calculated for each level to accept/reject the limits. VBE trials showed that the 90% CI fell within the acceptable limits of 80-125% for C_max, AUC_0-t and AUC_0-inf for the lower dissolution specification limit 5 and for the upper specification limit 3. The current investigation demonstrates new opportunities offered by mechanistic modelling and how this two-pronged approach (IVIVC and IVIVR-VBE) can be used to define clinically relevant dissolution specifications and the BE safe space, which can support post-approval changes for waiving bioequivalence studies and ensuring commercial product quality over the years.