Haptic Evaluation of 3D-printed Braille-encoded Intraoral Films

The three-dimensional (3D) printing technology has recently emerged in the pharmaceutical field, providing an array of applications for individualized dosing and elaborate formulation designs. However, an alternative asset of the 3D printing technology is the capability to imprint haptic identifiers directly onto the surface of the formulations. This approach can generate novel design concepts, that will serve specific populations for identifying the right treatment regimen, i.e., visually impaired people. Toward this direction, the fused deposition modelling (FDM) technique was investigated for manufacturing intraoral films and incorporating Braille characters on the available area. The films comprised a drug-loaded compartment and a backing layer, which are typical structural characteristics for buccal delivery. A hydrophilic polymer, i.e., hydroxypropyl methylcellulose, provided the polymer matrix for both compartments, whereas ketoprofen was incorporated in the study as model drug. The Braille-encoded texts were designed on top of the backing layer, complying with the Marburg Medium spacing convention for pharmaceutical Braille. Moreover, modifications on the standard spacing and dimension parameters were applied, to investigate the accuracy and repeatability of the FDM process. The fabricated films were subjected to a haptic evaluation study with the aid of visually impaired individuals, to assess the readability of the 3D-printed Braille-encoded text. The outcomes of the study highlighted the capacity of the FDM technology in combining novel manufacturing concepts for individualized therapies with customized services that can be provided to specific populations, as in the case of people with visual impairment.