Gellan Nanohydrogels: Novel Nanodelivery Systems for Cutaneous Administration of Piroxicam

The feasibility to use gellan nanohydrogels (Ge-NHs) as delivery system for the cutaneous administration of piroxicam (PRX) was investigated using gellan conjugated with cholesterol or riboflavin. The <i>in vitro</i> skin penetration studies through human epidermis were performed using a saturated aqueous drug solution, a 50% w/v Transcutol aqueous solution, and a commercially available PRX plaster as controls. Confocal microscopy, ATR-FTIR spectroscopy, circular dichroism, and a dynamometer assisted extrusion assay were performed to clarify the permeation mechanism of Ge-NHs. The skin permeation studies evidenced that Ge-NHs enhance the PRX retention in the epidermis and, at the same time, slow down the permeation process with respect to the controls. NHs can penetrate the <i>stratum corneum</i>, and then gradually disassemble thus diffusing in the viable epidermis reaching the <i>spinosum</i> layer. In conclusion, NHs represent a novel strategy to target poorly permeable compounds in the epidermis, thus improving the management of cutaneous pathologies