Batch sequential production of medicated Janus fibrous films of polyvinylpyrrolidone/shellac for treating pharyngitis.

Janus structures are highly popular for developing functional materials, including drug delivery systems, whereas batch production of Janus fibrous films represents one of the most difficult challenges. Here, based on a brand-new integrated multi-orifice spinneret, Janus fibrous films were fabricated directly through a sequential batch electrospinning process. The films contained a top layer of polyvinylpyrrolidone (PVP), borneol, sucralose, and acetaminophen (APAP) for rapid drug release, and a bottom layer of shellac, PVP, borneol, sucralose, and APAP for sustained drug release. Scanning electron microscopy results verified that both the top and bottom layers were composed of ultra-thin linear fibers without beads or spindles. X-ray diffraction and Fourier-transform infrared spectroscopy results verified that borneol and APAP were present in the Janus films in an amorphous state and exhibited good compatibility with the polymeric matrices. The Janus fibrous films can be cut into small patches for topical administration to treat pharyngitis. Artificial tongue and saliva models were exploited to conduct in vitro dissolution tests. Biphasic release of the loaded APAP from the artificial tongue surface was demonstrated. The mechanism underlying the new technique-based process-structure-performance relationship was proposed. The reported protocols provide a brand-new approach for batch creating Janus fibrous films, which can be further exploited for developing a wide variety of functional hierarchical structures.