Fabrication of multi-layered polymer-based polypill using single-nozzle Fused Deposition Modeling and its dissolution mechanism

Abstract

The meteoric rise of additive manufacturing has enabled it to create remarkable feats in the field of pharmaceutics and drug delivery applications. The main objective of this study was to print a polypill, having two drugs of common ailments in different layers, using a single nozzle Fused Deposition Modeling (FDM), instead of using a complex and cost-intensive dual extrusion printer. This was accomplished through a thermally fused filament. Myo-inositol (MI) and methylcobalamin (MCB) were the two drugs used for the present study. Initially, polyvinyl alcohol (PVA) filaments have been loaded with these drugs using Hot Melt Extrusion (HME) method and then, fused using heat and this blended filament has been fed into the FDM printing apparatus. These filaments have been used to finally obtain a polypill containing drugs in an alternate layer fashion. Various tests related to the filaments and tablets have been carried out to analyse the chemical, physical and thermal feasibility of this research attempt. The thermal analysis like Differential Scanning Calorimetry (DSC), Thermogravimetric (TGA) analysis tests confirmed filaments to be stable at printing temperature and FTIR results affirmed non-existence of any adverse degradation reaction in the drugs or other constituents. In-vitro dissolution studies were also conducted on the polypill and it was revealed that the dissolution rate for MI has been significantly higher than that of MCB drug. MI drug released completely in 5 h while MCB part was complete by 6.5 h. Finally, the drug dissolution behaviour was examined based on the dissolution data.