Prolonged-release of menthol through a superhydrophilic multilayered structure of balangu (Lallemantia royleana)-gelatin nanofibers

This study aimed to develop a sandwich structure based on electrospun mats derived from gelatin (central layer) and Balangu seed gum (outer layers) and to compare its capability for prolonging the menthol release in the oral phase compared to the gelatin monolayer mat. The mesh-like structure and the smooth and uniform surface of the electrospun mats designed in this study were authenticated by Atomic Force Microscopy (AFM). By designing the sandwich structure, the dissolution time and contact angle of the mats were increased and their bioadhesive strength decreased. The swelling degree of the gelatin mat (453.25 +/- 32.56%) was significantly higher than that of the sandwich mat (297.71 +/- 22.68%) (p < 0.05). Successful entrapment and the thermal stability of the produced mats were proved by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR) tests. The release kinetics in the human simulated saliva showed that the burst release of menthol from the structure of electrospun gelatin mats, due to its fast-dissolving nature, was well prolonged by the designed sandwich system. The Fickian Case-I release was the main mechanism in the menthol release and the Peppas-Sahlin was the most suitable model governing the release of menthol from these structures.