title: Analysis of 3D Prints by X-ray Computed Microtomography and Terahertz Pulsed Imaging.
abstract: A 3D printer was used to realise compartmental dosage forms containing multiple active pharmaceutical ingredient (API) formulations. This work demonstrates the microstructural characterisation of 3D printed solid dosage forms using X-ray computed microtomography (XμCT) and terahertz pulsed imaging (TPI).
  
  
  
  Printing was performed with either polyvinyl alcohol (PVA) or polylactic acid (PLA). The structures were examined by XμCT and TPI. Liquid self-nanoemulsifying drug delivery system (SNEDDS) formulations containing saquinavir and halofantrine were incorporated into the 3D printed compartmentalised structures and in vitro drug release determined.
  
  
  
  A clear difference in terms of pore structure between PVA and PLA prints was observed by extracting the porosity (5.5% for PVA and 0.2% for PLA prints), pore length and pore volume from the XμCT data. The print resolution and accuracy was characterised by XμCT and TPI on the basis of the computer-aided design (CAD) models of the dosage form (compartmentalised PVA structures were 7.5 ± 0.75% larger than designed; n = 3).
  
  
  
  The 3D printer can reproduce specific structures very accurately, whereas the 3D prints can deviate from the designed model. The microstructural information extracted by XμCT and TPI will assist to gain a better understanding about the performance of 3D printed dosage forms.
authors.affiliation: Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Markl
authors.affiliation: Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK.
authors.forename: J Axel
authors.initials: JA
authors.lastname: Zeitler
authors.affiliation: Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark.
authors.forename: Cecilie
authors.initials: C
authors.lastname: Rasch
authors.affiliation: Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark.
authors.forename: Maria Høtoft
authors.initials: MH
authors.lastname: Michaelsen
authors.affiliation: Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark.
authors.forename: Anette
authors.initials: A
authors.lastname: Müllertz
authors.affiliation: Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark.
authors.forename: Jukka
authors.initials: J
authors.lastname: Rantanen
authors.affiliation: Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rades
authors.affiliation: Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark. johan.botker@sund.ku.dk.
authors.forename: Johan
authors.initials: J
authors.lastname: Bøtker
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D017076:Computer-Aided Design; D004304:Dosage Forms; D016503:Drug Delivery Systems / Q000379:methods; D065546:Drug Liberation; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D010616:Phenanthrenes / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D016062:Porosity; D011327:Printing / Q000379:methods; D066330:Printing, Three-Dimensional; D013678:Technology, Pharmaceutical / Q000379:methods; D055069:Terahertz Imaging / Q000379:methods; D055114:X-Ray Microtomography / Q000379:methods; D014965:X-Rays
chemical_list: D004304:Dosage Forms; D004364:Pharmaceutical Preparations; D010616:Phenanthrenes; D011091:Polyesters; C033616:poly(lactide); D011142:Polyvinyl Alcohol; C023768:halofantrine
keywords: 3D printing; X-ray computed microtomography (XμCT); microstructure; polyvinyl alcohol (PVA); terahertz pulsed imaging (TPI)