Cyclodextrin-based nanogel of flurbiprofen for dermal application: In vitro studies and in vivo skin irritation evaluation

The aim of this study was to develop and characterize flurbiprofen (FB)-loaded cyclodextrin (CD) based nanogel formulations for dermal application. Nanogels were produced via emulsification solvent evaporation and then incorporated into a hydroxypropyl methyl cellulose (HPMC) gel. The visual examination, pH, viscosity, dynamic rheological measurements and drug content analysis of nanogels were assessed. In vitro and ex vivo permeation, stability, and skin irritation were performed. pH of the FB-loaded nanogel and the nanogels in HPMC were 10.6 ± 0.1 and 7.5 ± 0.1 (neutral) respectively. The highest and lowest viscosities were observed in FB-loaded nanogels and in FB-free nanogels in HPMC, respectively. The tangent δ and storage modulus values of FB-loaded nanogel in HPMC were higher than those of FB-loaded nanogel. FB from nanogels in HPMC was 100% by 48 h. The final nanogel formulation was physically and chemically stable over 12 months. Skin irritation test showed no skin irritation or cellular infiltration on the histological level. In vitro and ex vivo permeation showed that the nanogels could be effective and stable formulations, especially in the dermal application of a hydrophobic molecule.