Development of a nanotechnological hydrogel containing desonide nanocapsules in association with acai oil: design and in vivo evaluation

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.

纳米药物制剂（nanotechnological products）已被用作优化外用糖皮质激素（topical corticoids）治疗效果、降低其不良反应的策略。本研究旨在将菌核胶（sclerotium gum）添加至载地奈德（desonide）的阿萨伊油（açai oil）基纳米胶囊（nanocapsules）混悬液中制备水凝胶（hydrogels），并利用急性皮肤炎症动物模型研究其生物学效应。所制备的水凝胶具备符合外用给药要求的pH值（4.4~5.0）、纳米级平均粒径（131~165 nm）、假塑性流变行为（pseudoplastic behavior），且可在室温条件下稳定存放30天。体外皮肤渗透/透皮穿透实验结果显示，与市售凝胶膏剂（0.16 μg·cm⁻²）相比，纳米技术水凝胶组的表皮中滞留的地奈德量更高（0.33~0.36 μg·cm⁻²，p<0.05）。在真皮层中，纳米结构水凝胶的地奈德滞留量低于非纳米结构制剂（p<0.05）。该结果提示更少药物进入体循环，因此有望降低不良反应的发生风险。在抗炎活性方面，本研究制备的水凝胶可同时减轻耳肿胀与炎症细胞浸润，其药效与市售制剂相当，尽管后者的药物浓度为本研究制剂的两倍。综上，本研究开发的水凝胶有望成为治疗皮肤疾病的颇具前景的策略。