Hot-Melt Processed Glibenclamide Glassy Solutions: A Novel Oral Delivery Platform for Enhanced Bioavailability in Diabetes

Background/Objectives: Hot-melt injection molding (HMIM) was evaluated as a solvent-free process for the preparation of glibenclamide (GLB), a poorly soluble BCS Class II drug, glassy solutions with the objective of improving dissolution and bioavailability for diabetes. Methods: GLB was blended at a concentration of 10% w/w with PVP K25, PVP VA64, and Soluplus® (SOL) matrices. The miscibility of the GLB–polymer systems (matrices) was calculated based on the Hansen solubility parameters and validated using differential scanning calorimetry (DSC) analysis. The HMIM extrudates were milled into granules and analysed for their solid-state properties (DSC, XRPD, FTIR, and SEM studies), and flow properties. The produced granules were compressed into immediate release tablets and assessed for in vitro performance, stability, and in vivo bioavailability using 20 healthy male Sprague Dawley rats. Results: Findings revealed the formation of single-phase glassy solutions, specifically for PVP VA64 and SOL, which also exhibited advantageous manufacturing and extrudate clarity. The glassy solution formulations showed considerably improved dissolution characteristics compared with the crystalline GLB and the commercial product. The glassy solution formulations displayed fast drug release for PVP K25 and PVP VA64, and biphasic drug release for SOL. Stability testing confirmed the capability of PVP VA64 and SOL to maintain GLB in a molecularly dispersed, amorphous state for 12 months. The in vivo assessment revealed an increase in relative bioavailability to 246.3% and 124.5% for the SOL and PVP VA64 formulations when compared to the commercial formulation. Conclusions: Overall, the findings demonstrate the potential of HMIM-processed glassy solutions, especially those prepared using SOL, as promising platforms for promoting oral delivery of the poorly soluble antidiabetic GLB.