Novel drug delivery devices for providing linear release profiles fabricated by 3DP.

Novel doughnut-shaped multi-layered drug delivery devices (DDDs) were developed with local variations of the drug and release-retardant material for providing linear release profiles. Based on computer-aided design models, different DDDs containing acetaminophen as a model drug, hydroxypropyl methylcellulose as matrix and ethyl cellulose (EC) as a release-retardant material were prepared automatically using a three-dimensional printing (3DP) system. In vitro dissolution assays demonstrated that all the 3DP DDDs had with different diameters, heights, concentrations of EC and central hole diameters were able to give linear release profiles. Morphological and erosion studies showed that acetaminophen was released through a simultaneous surface erosion process involving the outer peripheries and inner apertures. The barrier layers on both bases of DDDs had good adhesion strength with the drug-contained regions and offered consistent release retardation for the whole duration of the dissolution process. The release time periods of the DDDs were dependent on the annular thicknesses or the passes of binder solution containing a release-retardant material. The dosage of the DDD can be adjusted independently by changing the heights of the DDDs. Thus, 3DP is capable of offering novel strategies for developing DDDs with complex design features for desired drug release profiles.