Box-Behnken design optimization of mucoadhesive chitosan-coated nanoemulsions for rosmarinic acid nasal delivery—In vitro studies

Development, physico-chemical characterization and in-vitro studies of hydrogels containing rosmarinic acid-loaded nanoemulsion for topical application

“…It can be observed that all the formulations presented a similar RA release profile, releasing significantly lower amounts ( P < 0.05) of RA in comparison with the control. Prolonged release is an important factor in the development of topical systems and was observed in‐vitro for formulations probably associated with the RA diffusion from the oil core of nanoemulsions . However, the RA released from nanoemulsions (NE RA and NE RAtw ) were faster in comparison with the formulation thickened in hydrogel (HNE RA , HNE RAtw ).…”

“…RA‐loaded nanoemulsions were prepared by a spontaneous emulsification procedure as previously described by Fachel et al . The components of the oil phase (egg‐lecithin 2.5% w/v, MCT 6% w/v, and RA) were dissolved in ethanol and poured in the aqueous phase, containing or not a nonionic cosurfactant (Tween ® 80 1% w/v), under constant stirring.…”

“…After 8 h, aliquots of the fluid receptor were collected from all of the diffusion cells. The skin was dried with a swab, removed from diffusion cells, cut into small pieces and extracted with 2 ml of methanol for 45 min in ultrasound . Finally, the samples were filtered and then analysed by the UFLC method as described in section RA determination by ultrafast liquid chromatography.…”

“…At the end of treatments (48 h), cells were incubated with PI (7.5 μ m ) for 60 min. Images were captured using a digital camera connected to an inverted microscope (Olympus IX71, Tokyo, Japan) with a standard rhodamine filter (excited at 515 e 560 nm) …”

“…Our research group has recently been interested in the development of topical nanoemulsions as delivery systems for RA. Nanoemulsions are dispersions of two immiscible liquids (oil‐in‐water) stabilized by an appropriate surfactant system, that have been widely studied as a promising alternative for the treatment of skin diseases and for cosmetics purposes, since their small droplet sizes can improve active lipophilic molecules penetration through the skin, increasing their topical effect . Nevertheless, for topical application, the low viscosity from nanoemulsions is a concern and the design of a semisolid formulation is a key consideration.…”