Terbinafine-loaded biocompatible hydrogel patches composed of hydroxyethyl methacrylate and methacrylic acid with remarkable antifungal activities

Abstract Oral administration of terbinafine hydrochloride for the treatment of superficial mycoses in the targeted skin area may require high concentrations due to first-pass metabolism and intensive plasma protein binding. To address these challenges, this study aimed to fabricate hydrogel patches for localized delivery of terbinafine hydrochloride. The patches were developed using methacrylic acid and 2-hydroxyethyl methacrylate monomers through a free radical polymerization technique. Infrared spectroscopy, field emission scanning electron microscopy, and time-dependent swelling tests were performed to examine the physicochemical, structural, and morphological characteristics of hydrogel patches. Hydrogels exhibit interconnected highly porous structures suitable for drug loading and controlled release. Biocompatibility was assessed through in vitro cytotoxicity and comet assays, showing no significant cytotoxic or genotoxic effects on human embryonic kidney cells, even at high extract concentrations. Terbinafine was loaded into biocompatible hydrogels with different monomer ratios, and it was found that both the loading content (from 3.84 to 5.83%) and the entrapment efficiency (from 26.63 to 41.45%) increased as the methacrylic acid composition increased. These patches can release the drug at higher concentrations depending on their methacrylic acid content while retaining the drug's inhibitory action on yeast microbiological growth. These findings suggest that the developed hydrogel patches could serve as efficient platforms for topical antifungal therapy following further clinical studies. Graphical abstract