Investigation of the processing window for Affinisol and Plasdone - S630 polymers during Hot-melt extrusion (for 3D printing by fused deposition modelling)

INTRODUCTION

In recent years, the use of 3D printing (3DP) for formation of custom dose forms has received increasing research interest for pharmaceutical applications. To date limited API loadings have been achieved. Current fused deposition modelling (FDM) approaches utilise a formulated filament (e.g. polymer and active) as a feedstock which can be made by hot-melt extrusion (HME). One key purpose of this work is to explore methods of achieving developing a viable routes to establishing wider ranging API loading using HME as a filament former.

During hot-melt extrusion establishing a viable operating space for subsequent formulation and processing is essential. This processing space must avoid conditions resulting in degradation by thermal or mechanical energy and deliver extruded filament with suitable properties for subsequent processing (e.g. 3D printing)

As a first step, two pharmaceutical polymers, have been processed across the full operating range of a twin screw extruder (TSE) in order to identify processing space where degradation is likely to occur and where it can be avoided.

As a second step, the HME process was further developed to produce up to 50:50 wt/wt API loaded HPMC based filament of suitable character for 3DP)f dose forms by FDM.