Electrospun Integrated Janus Nanofibers for Asynchronous Delivery of Finasteride and Tibetan Medicine

Background: Simultaneous controlled release of multiple therapeutics from a single dosage form is a major frontier in modern pharmaceutics and a key strategy for modernizing traditional Chinese medicine. Methods: Using finasteride (FIN) and a Jing-Zhu hybrid Tibetan (JZ) herbal medicine as model agents for prostatitis therapy, we developed a modified tri-fluid electrospinning process to fabricate drug-co-loaded Janus medicated nanofibers. Soluble polyvinylpyrrolidone (PVP) and insoluble ethylcellulose (EC) served as carrier matrices for the dual faces of the Janus architecture, encapsulating JZ herbal medicine and FIN, respectively. A custom-designed spinneret—comprising two parallel stainless steel tubes nested within a plastic sheath—was engineered to enable side-by-side fiber formation. Results: Scanning and transmission electron microscopy confirmed linear morphologies with a definitive side-by-side Janus structure. X-ray diffraction and Fourier Transform Infrared Spectroscopy revealed that all active ingredients were dispersed in an amorphous state, reflecting polymer–drug compatibility. Encapsulation efficiencies reached 96.34 ± 0.47% for FIN and 94.15 ± 0.48% for JZ herbal medicine. A newly devised water-droplet assay demonstrated that almost all the nanofibers exhibited the intended side-by-side configuration, as evidenced by the rapid dissolution of the PVP side. In vitro release studies showed an initial pulsatile burst of JZ herbal medicine followed by a sustained FIN release profile, as suggested by the single-drug-loaded Janus nanofibrous controls. Conclusions: The present Janus nanostructure system, fabricated via a facile co-shell solvent electrospinning process, has the potential to enable the concurrent yet asynchronous delivery of FIN and JZ herbal components within a single nano-dosage form. This conceptual advance expands the toolkit for designing combination nanomedicines, allowing independent modulation of release kinetics for individual drugs to maximize prospective joint efficacy.