Poloxamer-hydroxyethyl cellulose-α-cyclodextrin supramolecular gels for sustained release of griseofulvin

Supramolecular gels of poloxamer-hydroxyethyl cellulose (HEC)-α-cyclodextrin (αCD) were developed aiming to obtain synergisms regarding solubilization and sustained release of griseofulvin for topical application. The effects of αCD concentration (0-10%w/w) on the phase behavior of aqueous dispersions of Pluronic(®) P123 (14%w/w) mixed with HEC (2%w/w) were evaluated at 4, 20 and 37°C. The cooperative effects of the inclusion complex formation between poly(ethylene oxide) (PEO) blocks and HEC with αCD prevented phase separation and led to supramolecular networks that solubilize the antifungal drug. Rheological and bioadhesive properties of gels with and without griseofulvin could be easily tuned modulating the polymers proportions. Supramolecular gels underwent sol-gel transition at lower temperature than P123 solely dispersions and enabled drug sustained release for at least three weeks. All gels demonstrated good biocompatibility in the HET-CAM test. Furthermore, the drug-loaded gels showed activity against Trichophyton rubrum and Trichophyton mentagrophytes and thus may be useful for the treatment of tinea capitis and other cutaneous fungal infections.