Engineered Spindles of Little Molecules Around Electrospun Nanofibers for Biphasic Drug Release

Biphasic drug release is a popular advanced drug controlled release profile that has been drawing increasing attention from many fields. Electrospun nanofibers and their derivatives can be act as a strong platform for developing biphasic release dosage forms. In this study, a modified coaxial electrospinning was implemented, in which little molecule solutions that contain a drug ibuprofen (IBU) and polyethylene glycol (PEG) were exploited as a sheath fluid to surround the core solutions composed of polymer ethyl cellulose (EC) and IBU. The prepared nanofiber-based structural hybrids, i.e., engineered spindles-on-a-string (SOS) products, were successfully created and subjected to a series of characterizations. Scanning electron microscopy and transmission electron microscopy results showed the engineered SOS structures. IBU and the carriers EC and PEG had good compatibility, as suggested by X-ray diffraction and Fourier transform infrared spectroscopy assessments. In vitro dissolution tests verified that the SOS products were able to provide a typical biphasic release profile, releasing 40% of the loaded IBU within 1 h in an immediate manner in the first phase, and the rest of the IBU in a sustained manner in the second phase. A combined mechanism of erosion and diffusion is proposed for manipulating the IBU molecule release behaviors. Graphical abstract