Theoretical and Experimental Validation of Praziquantel with Different Polymers: Miscibility, Phase Diagram and Estimation of Flory-Huggins Interaction Parameter to select Appropriate Matrix for Hot-melt Extrusion

Ukti Bhatt , Upadhyayula Suryanarayana Murty, Subham Banerjee 1

8th WCPSDM.2021. APR.Published Online 18 APR 2021

Abstract : Selection of appropriate matrix, for the preparation of amorphous extrudate in hot-melt extrusion (HME) deals with the study of various solid-state properties of the drug and polymer. It is therefore to have an appropriate knowledge of polymer-drug miscibility, interaction between drug-polymer on mixing, and the Gibb’s free thermal energy of mixing for screening of polymers through thermodynamic phase diagrams to be suitable amorphous matrix system for HME. Here, we evaluated the possibility of three different polymers namely, Eudragit®EPO, Poly-vinyl alcohol (PVA), Kollicoat®IR (KIR) with the Praziquantel (PZQ) as a suitable matrix for HME. Solubility parameter’s approach in terms of theoretical calculation was done as a preliminary study for validation of miscibility between PZQ with three different polymers. Theoretical and experimental validation study by using Flory-Huggins interaction parameter value using melting point depression approach and the effect PZQ loading on the interaction parameter was systematically validated to predict thermodynamic phase diagrams & Gibbs free energy of mixing for screening of these polymers for the preparation of amorphous extrudate. Using phase diagram thermal processing temperature for HME was conducted using T-φ phase diagram to obtain appropriate matrix. The obtained extrudates were further validated through physical appearance, microscopic structure, thermal and functional group characterizations followed by PZQ assay. Thus, in terms of considering the solid-state properties, processing parameters of HME was selected to obtain stable extrudates and appropriate matrix for PZQ loading. The further optimized filament was further processed into Fused Deposition modelling and formed into 3D printed Caplet, making a precision dosage form.