So far, microdevices for oral drug delivery have been fabricated as square or cylindrical reservoir structures with a localized and unidirectional release. The fabrication is usually carried out using sophisticated and costly microfabrication techniques. Here, 3D printing of microreservoirs on sacrificial substrates is presented. This approach allows the devices to be accurately arranged in predetermined patterns, enabling implementation into batch production schemes in which the fabrication of the devices is linked to processing steps such as automated drug loading and sealing. Moreover, design and 3D printing of alternative geometries of minireservoirs featuring anchor-like surface structures for improved mucoadhesion and intestinal retention is demonstrated. Surface texturing of minireservoirs increases mucoadhesion of the devices up to two-fold compared to a nonstructured control. The structuring also leads to a strong bias in mucoadhesion in different orientations, which can facilitate a correct orientation of the devices and thus lead to unidirectional release of drugs toward the intestinal mucosa for increased drug uptake.
Keywords: micro additive manufacturing; microcontainers; microdevices; minireservoirs; mucoadhesion; oral drug delivery.