Film-Forming Nanogels: Effects of Nanocarriers and Film-Forming Gel on the Sustained Release of Curcumin

Background: Although film-forming hydrogels possess the advantages of both film and hydrogel dosage forms, certain limitations still remain. Objective: This study aims to investigate the use of film-forming hydrogels and the effects of nanocarriers on the sustained release of a poorly water-soluble drug, curcumin. Methods: The film-forming hydrogels contained either zein or polyvinylpyrrolidone as a film former, in addition to hydroxypropyl methylcellulose, oleic acid, ethanol and water. Curcumin was encapsulated in poly(lacticco- glycolic acid) and gelatine nanoparticles using a sonoprecipitation method. Free drug and drug-loaded nanoparticles were later dispersed into blank hydrogels to produce the film-forming nanogels. Results: The results suggested that the encapsulation of curcumin in nanoparticles could reduce the drug particle size to less than 200nm for easier diffusion and could shield curcumin from chemical interactions that limit its topical permeability. Curcumin was more compatible with gelatine nanoparticles than with poly(lactic-coglycolic acid) nanoparticles, and gelatine nanoparticles, in turn, were more compatible with zein than with polyvinylpyrrolidone film-forming nanogels. Therefore, gelatine nanoparticles in zein film-forming nanogels greatly elevated the permeability of curcumin by over five times that afforded by gelatine nanoparticles in polyvinylpyrrolidone film-forming nanogels. Conclusion: This research suggested that film-forming nanogel is a promising drug delivery system for both improved permeability and sustained topical diffusion of the extremely hydrophobic drug curcumin depending on the compatibility between the nanocarrier and the film-forming hydrogel.