L-Menthol-Loadable Electrospun Fibers of PMVEMA Anhydride for Topical Administration

Poly(methyl vinyl ether-alt-maleic anhydride) (PMVEMA) of 119 and 139 molecular weights (P119 and P139, respectively) were electrospun to evaluate the resulting fibers as a topical delivery vehicle for (L-)menthol. Thus, electrospinning parameters were optimized for the production of uniform bead-free fibers from 12% w/w PMVEMA (& PLUSMN;2.3% w/w menthol) solutions, and their morphology and size were characterized by field emission scanning electron microscopy (FESEM). The fibers of P119 (F(119)s) and P139 (F(139)s) showed average diameter sizes of approximately 534 and 664 nm, respectively, when unloaded, and 837 and 1369 nm when loaded with menthol. The morphology of all types of fibers was cylindrical except for F(139)s, which mostly displayed a double-ribbon-like shape. Gas chromatography-mass spectrometry (GC-MS) analysis determined that not only was the menthol encapsulation efficiency higher in F(139)s (92% versus 68% in F(119)s) but also that its stability over time was higher, given that in contrast with F(119)s, no significant losses in encapsulated menthol were detected in the F(139)s after 10 days post-production. Finally, in vitro biological assays showed no significant induction of cytotoxicity for any of the experimental fibers or in the full functionality of the encapsulated menthol, as it achieved equivalent free-menthol levels of activation of its specific receptor, the (human) transient receptor potential cation channel subfamily M (melastatin) member 8 (TRPM8).

Automated summary

Electrospun fibers from PMVEMA and menthol solutions were characterized, showing higher encapsulation efficiency and stability of menthol in P139 fibers compared to P119 fibers. The morphology and size of the fibers were analyzed, and in vitro biological assays demonstrated no cytotoxicity induction.