In vitro transdermal release of crocin from electrospun saffron and its comparison with in vitro digestion

Saffron extract (SE) was electrospun into pullulan-pectin (Pl-Pc), pullulan-pea protein-pectin (Pl-Pp-Pc), or zein nanofibers (NFs) for transdermal food supplement. The in vitro transdermal permeation mechanism and kinetics of SE from NFs were studied and compared with those of in vitro digestion. The ATR-FTIR spectra of NFs provided information on the interactions between SE and wall biopolymers. The release of SE from NFs was investigated in stimulated gastrointestinal media (SGF and SIF) using a dialysis bag, and transdermal permeation studies were performed via a membrane in a Franz diffusion cell. The wettability and swelling ratio of the NFs were determined. The Pl-Pc-SE sample, which has the lowest contact angle and the highest swelling index, resulted in the highest release of SE during digestion. The Ritger-Peppas and Higuchi models best represented the experimental release data from digestion and transdermal permeation. The release profile of SE from zein NFs in SGF was described using a non-Fickian mechanism. In contrast, the release mechanism for Pl-based NFs in SGF and all NFs during both release experiments was Fickian-controlled diffusion transport. The results indicate that NFs can be successfully used for the controlled delivery of SE and have the potential for transdermal applications as a dietary supplement.