Dissolution testing of modified release products with biorelevant media: An OrBiTo ring study using the USP apparatus III and IV

Predictive dissolution modeling across USP apparatuses I, II, and III

Dissolution testing provides in vitro drug release characterization and serves a critical role in the development of solid oral dosage forms. The most common dissolution apparatuses are the USP apparatuses I and II, for which in silico tools have been previously developed for predictive dissolution modeling (PDM). While apparatuses I and II serve the greater volume of projects, apparatus III offers higher agitation levels and multivessel capabilities, which is critical for certain projects, and the physics of which have not been previously characterized. To mitigate that knowledge gap, the present work characterizes the transport physics and thermodynamics of dissolution apparatus III, such that a 1-D model is established and validated which scales release kinetics with agitation level across apparatuses I, II, and III. The resulting PDM is calibrated with at least two dissolution experiments at different agitation levels, for a particular formulation-medium combination, after which release kinetics are predicted within the design spaces of the three apparatuses. Calibration data can come from experiments using a single apparatus or different apparatuses, while still predicting across all three apparatuses. Erosion-based formulations are used for validation. Additionally, apparatus III vessel residence time analysis is demonstrated.

Integrating In Vitro Dissolution and Physiologically Based Pharmacokinetic Modeling for Generic Drug Development: Evaluation of Amorphous Solid Dispersion Formulations for Tacrolimus

Objectives: Tacrolimus, a Biopharmaceutics Classification System (BCS) class II drug, is widely used for transplant patients to prevent graft rejection. To enhance its bioavailability, amorphous solid dispersion (ASD) formulations were developed and evaluated. The release properties of several ASD-based tacrolimus formulations were studied using an in-house USP IV dissolution method. Methods: The pharmacokinetics of a promising test product were compared with the commercially available Advagraf® in a pilot clinical bioequivalence study with 12 healthy subjects. A previously published PBPK model for tacrolimus was validated using in vivo data and then applied to predict the human pharmacokinetics of several ASD-based tacrolimus formulations. Results: This study compares the pharmacokinetic (PK) parameters-AUC, Cmax, and Tmax-of Advagraf® and a test formulation using two methodologies: one incorporating the dissolution profile directly into the PBPK model and the other utilizing the DLM approach. The results show that both methods provided accurate predictions for Cmax and Tmax, with the dissolution profile approach underestimating AUC slightly, while the DLM method predicted AUC adequately. Sensitivity analysis refining the DLM scalars in the Ileum and Colon led to optimized predictions of PK parameters. Furthermore, this study explores the use of PBPK modeling to predict in vivo behavior for additional tacrolimus formulations, highlighting the influence of formulation composition, such as the inclusion of Eudragit-S100, on dissolution profiles and bioavailability. Conclusions: This study evaluates formulations with different compositions and manufacturing characteristics; key factors that could influence their performance in the body were identified. These insights-spanning qualitative, quantitative, and manufacturing aspects-can greatly simplify the development of generic drugs, offering strong evidence of the critical role that physiologically based pharmacokinetic (PBPK) modeling can play in the early phases of generic drug development, especially in designing and assessing biopredictive dissolution methods.

Can in vitro/in silico tools improve colonic concentration estimations for oral extended-release formulations? A case study with upadacitinib

Upadacitinib, classified as a highly soluble drug, is commercially marketed as RINVOQ®, a modified-release formulation incorporating hydroxypropyl methylcellulose as a matrix system to target extended release throughout the gastrointestinal (GI) tract. Our study aimed to explore how drug release will occur throughout the GI tract using a plethora of in vitro and in silico tools. We built a Physiologically-Based Pharmacokinetic (PBPK) model in GastroPlus™ to predict the systemic concentrations of the drug when administered using in vitro dissolution profiles as input to drive luminal dissolution. A series of in vitro dissolution experiments were gathered using the USP Apparatus I, III and IV in presence of biorelevant media, simulating both fasted and fed state conditions. A key outcome from the current study was to establish an in vitro-in vivo correlation (IVIVC) between (i) the dissolution profiles obtained from the USP I, III and IV methods and (ii) the fraction absorbed of drug as deconvoluted from the plasma concentration-time profile of the drug. When linking the fraction dissolved as measured in the USP IV model, a Level A IVIVC was established. Moreover, when using the different dissolution profiles as input for PBPK modeling, it was also observed that predictions for plasma Cmax and AUC were most accurate for USP IV compared to the other models (based on predicted versus observed ratios). Furthermore, the PBPK model has the utility to extract the predicted concentrations at the level of the colon which can be of utmost interest when working with specific in vitro assays.