Development of Hot Melt Extruded Co-Formulated Artesunate and Amodiaquine- Soluplus Solid Dispersion System in Fixed-Dose Form: Amorphous State Characterization and Pharmacokinetic Evaluation.

Introduction: This study aims to develop co-amorphous Solid Dispersion (SD) system containing antimalarials Artesunate (ARS) and Amodiaquine (AMQ) to improve its oral bioavailability employing the Hot Melt Extrusion (HME) technique. Soluplus was selected as a polymeric excipient, whereas Lutrol F127, Lutrol F68, TPGS, and PEG400 as surfactants were incorporated along with Soluplus to enhance extrudability, improve hydrophilicity, and improve the blend viscosity during HME. Soluplus with surfactant combination successfully stabilizes both drugs during extrusion by generating SD because of its lower glass transition temperature (Tg) and viscoelastic behavior.

Methods: Physicochemical characterizations were performed using FTIR, DSC, TGA, and XRD, which confirmed the amorphousization of drugs in the SD system. The molecular level morphology of the optimized formulation was quantified using high-resolution techniques such as Atomic-Force Microscopy (AFM), Raman spectral, and mapping analysis. The transition of the crystalline drugs into a stable amorphous form has been demonstrated by 1H-NMR and 2D-NMR studies. The pharmacokinetics study in rats showed that the SD-containing drug-Soluplus-TPGS (FDC10) formulation has 36.63-56.13 (ARS-AMQ) folds increase in the Cmax and 41.87-54.34 (ARS-AMQ) folds increase AUC (0-72) as compared to pure drugs.

Results: Pharmacokinetic analysis shows that a fixed-dose combination of 50:135 mg of both APIs (ARSAMQ) significantly increased oral bioavailability by elevating Cmax and AUC, in comparison to pure APIs and also better than the marketed product Coarsucam.

Conclusion: Therefore, the developed melt extruded co-amorphous formulation has enhanced bioavailability and has more effectiveness than the marketed product Coarsucam. .