Electrospun PLA/PVP K90 Biphasic-Release Sublingual Film for Motion Sickness Treatment

To overcome the limitations of traditional motion sickness medications—slow onset of action, short duration of efficacy, and poor patient compliance—this study employed coaxial electrospinning technology. Poly(lactic acid) (PLA) and polyvinylpyrrolidone K90 (PVP K90) were used as composite carrier materials. The sheath layer is composed of highly hydrophilic PVP K90, loaded with the antihistamine diphenhydramine (DPH). The core layer, composed of biodegradable PLA with excellent sustained-release properties, carries the anticholinergic drug scopolamine hydrobromide (SH). This core–sheath nanostructured nanofiber sublingual film delivers dual anti-motion sickness drugs. A series of characterization tests revealed that the sublingual membrane exhibits a linear morphology with a distinct core–shell nanostructure. The drugs DPH and SH are distributed in an amorphous state within the sheath and core layers, respectively. Wetting performance tests indicate that the membrane’s wettability falls between those of monofilament membranes. In vitro drug release experiments revealed that DPH exhibited a “rapid onset + sustained release” biphasic profile, with cumulative release reaching 60% within 2 h and approaching complete release by 10 h, primarily via Fickian diffusion (n = 0.30). SH exhibited prolonged sustained release, approaching complete release at 12 h via non-Fickian diffusion (n = 0.55). Cytotoxicity and vital/necrotic staining experiments mutually corroborated that cell viability remained above 80%, further validating the safety and efficacy of PLA/PVP as a combined drug delivery carrier. This study provides a novel delivery system for motion sickness treatment, offering significant theoretical value and broad clinical application prospects.