RESUMO
Nanotechnological products have been used as strategies to optimize the therapy and minimize the side effects of topical corticoids. The objective of this study was to develop hydrogels by the addition of sclerotium gum to the suspensions of desonide-loaded açai oil-based nanocapsules and to study their biological effect using an animal model of acute skin inflammation. The hydrogels presented a pH compatible with topical application (4.4 to 5.0), nanometric mean diameter (131 to 165 nm), pseudoplastic behavior, and stability under room conditions during 30 days. The in vitro skin permeation/penetration study demonstrated that a higher amount of desonide (p < 0.05) was retained in the epidermis from the nanotechnological-hydrogels (0.33 to 0.36 µg.cm2) in comparison to the commercial gel cream (0.16 µg.cm2). In the dermis, the nanostructured hydrogels promoted a lower DES retention compared to the non-nanostructured formulations (p < 0.05). This result may indicate a smaller amount of drug reaching the bloodstream and, thus, fewer side effects can be expected. Concerning the anti-inflammatory effect, the developed hydrogels reduced both ear edema and inflammatory cell infiltration, showing an effect comparable to the commercially available formulation, which presents twice the drug concentration. The hydrogels developed may be considered a promising approach to treat dermatological disorders.
Assuntos
Nanocápsulas , Animais , Anti-Inflamatórios/uso terapêutico , Desonida/farmacologia , Glucocorticoides , HidrogéisRESUMO
This study aimed to develop Eudragit® RL 100 nanocapsules loaded with desonide (DES) using açai oil (AO) or medium chain triglycerides (MCT) as oil core. Pre-formulation study showed that AO and MCT are suitable for nanocapsules preparation. The nanocapsules prepared with AO and MCT presented mean particle size around 165 and 131â¯nm, respectively; polydispersity index values <0.20, positive zeta potential values, drug content close to the theoretical value (0.25â¯mgâ¯mL-1), and DES encapsulation efficiency around 81%, regardless of the oil core (AO or MCT). Considering the photoinstability reported to DES, photodegradation studies were performed. The UV-A (365â¯nm) and UV-C (254â¯nm) photodegradation studies revealed less DES degradation when associated to the nanocapsules containing AO in comparison to those with MCT. The in vitro release study showed a biphasic release profile for both nanocapsule suspensions: an initial burst effect followed by a prolonged DES release. In addition, the formulations were considered non-phototoxic at 0.5â¯mgâ¯mL-1 when tested on 3â¯T3 murine fibroblasts and HaCaT human keratinocytes using the MTT and NRU viability assays. The irritant potential of the prepared nanocapsules and DES in free form were evaluated by HET-CAM method. All formulations were classified as slightly irritant, including the non-associate DES. In conclusion, the nanocapsule formulations developed in this study may be promising for therapeutic applications.