Microstructure Analysis And Drug Release Characteristics Of 3D Printed PVA-based Printlets™

Fused deposition modeling (FDM) 3–Dimensional (3D) printing is becoming an increasingly significant technology in the pharmaceutical sciences, since it allows the manufacture of personalized oral dosage forms by deposition of thin layers of material. FabRx, in collaboration with researchers from University College London – School of Pharmacy, University of Santiago de Compostela and Astellas, have recently published a research paper in the International Journal of Pharmaceutics in which the effect of the internal structure -micropore volume- of drug loaded 3D printed capsule-shape tablets (Printlets™) on drug dissolution behaviour was studied.

Graphical abstract of the article.

A filament extruder was used to obtain filaments of polyvinyl alcohol (PVA) containing paracetamol (acetaminophen) or caffeine appropriate for 3D printing. The filaments were used to manufacture Printlets™ for oral administration using a FDM 3D printer.

The micropore volume of the Printlets™ was primarily determined by the presence of large pores due to gaps in the printed layers/net while printing, and the porosity of the Printlets™ was 10 fold higher than the porosity of the extruded filament.

A scanning electron microscopy image showing the internal structure of a cross-section of a Printlet™ and an image of the cross-section of a low dose paracetamol Printlet™ after porosity analysis.

Dynamic dissolution drug release tests on the Printlets™ in biorelevant bicarbonate media revealed distinctive release profiles, which were dependent on drug solubility and drug loading. Porosity of the Printlets™ bore no relevance in predicting the different drug release profiles.

Response surface for percentage of drug released 270min (D270) as a function of drug content in the formulation and drug solubility.

This study helps to elucidate which factors influence drug release from this type of new dosage form and confirms the potential of 3D printing to fabricate Printlets™.

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