3D-micro-patterned fibrous dosage forms for immediate drug release

Highlights: • 3D-micro-patterned fibrous dosage forms are prepared, and tested and modeled for drug release. • It is shown that the microstructure and the disintegration time of fibrous dosage forms are predictable. • The fibrous dosage forms enable predictable design and manufacture of immediate-release pharmaceuticals. - Abstract: At present, the most prevalent pharmaceutical dosage forms, the orally-delivered immediate-release tablets and capsules, are porous, granular solids. They disintegrate into their constituent particulates upon ingestion to release drug rapidly. The design, development, and manufacture of such granular solids, however, is inefficient due to difficulties associated with the unpredictable inter-particle interactions. Therefore, to achieve more predictable dosage form properties and processing, we have recently introduced melt-processed polymeric cellular dosage forms. The cellular forms disintegrated and released drug rapidly if the cells were predominantly interconnected. Preparation of interconnected cells, however, relies on the coalescence of gas bubbles in the melt, which is unpredictable. In the present work, therefore, new melt-processed fibrous dosage forms with contiguous void space are presented. The dosage forms are prepared by melt extrusion of the drug-excipient mixture followed by patterning the fibrous extrudate on a moving surface. It is demonstrated that the resulting fibrous structures are fully predictable by the extruder nozzle diameter and the motion of the surface. Furthermore, drug release experiments show that the disintegration time of the fibrous forms prepared in this work is of the order of that of the corresponding single fibers. The thin fibers of polyethylene glycol (excipient) and acetaminophen (drug) in turn disintegrate in a time proportional to the fiber radius and well within immediate-release specification. Finally, models of dosage form disintegration and drug release by single fibers and fibrous dosage forms are developed. It is found that drug release from fibrous forms is predictable by the physico-chemical properties of the excipient and such microstructural parameters as the fiber radius, the inter-fiber spacing, and the volume fraction of water-soluble excipient in the fibers.