Pharmaceutical Sciences Graduate Program, College of Pharmacy, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Pharmaceutical Sciences Graduate Program, College of Pharmacy, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil; College of Pharmacy, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Int J Pharm. 2021 Mar 1;596:120294. doi: 10.1016/j.ijpharm.2021.120294. Epub 2021 Jan 23.
The in vivo skin penetration by dermal microdialysis and the pharmacological efficacy of a chitosan hydrogel containing capsaicinoids-loaded nanocapsules (CHNC) was evaluated in this study. Such gel has previously been proven to control capsaicinoids release and decrease the drugs side effects in humans. The nanocapsules containing capsaicinoids had an average size around 150 nm, with a low polydispersity index, positive zeta potential, and high encapsulation efficiency of the drugs. The CHNC showed intact nanocapsules, a slightly acid pH value, and a pseudoplastic behavior suitable for topical application. Microdialysis experiments showed a 1.6-fold increase in the concentration of capsaicinoids in the dermis (after 12 h of its application) when CHNC was administered compared to a chitosan hydrogel containing capsaicinoids in hydroethanolic solution (CHET) and the commercial cream. The CHNC showed antiallodynic and antihyperalgesic effects from 6 h to 96 h after treatment initiation, whereas CHET and the commercial cream showed antiallodynic and antihyperalgesic effects only at 48 h and 96 h after treatment initiation, respectively. CHNC and the commercial cream maintained antihyperalgesic activity for 6 days after treatment interruption. For mechanical allodynia, the antinociceptive effect was maintained for 48 h after treatment interruption only with CHNC. In conclusion, CHNC is a promising formulation for treating peripheral neuropathic pain.
本研究评估了经皮微透析的体内皮肤渗透和含有辣椒素纳米胶囊（CHNC）的壳聚糖水凝胶的药理学功效。这种凝胶先前已被证明可以控制辣椒素的释放并减少药物在人体中的副作用。载有辣椒素的纳米胶囊平均大小约为 150nm，具有低多分散指数、正 ζ 电位和高药物包封效率。CHNC 显示出完整的纳米胶囊、略酸性的 pH 值和适用于局部应用的假塑性行为。微透析实验表明，与含有乙醇溶液中的辣椒素的壳聚糖水凝胶（CHET）和商业乳膏相比，CHNC 给药后 12 小时真皮中辣椒素的浓度增加了 1.6 倍。CHNC 在治疗开始后 6 至 96 小时表现出抗痛觉过敏和抗痛觉过高的作用，而 CHET 和商业乳膏仅在治疗开始后 48 和 96 小时表现出抗痛觉过敏和抗痛觉过高的作用。CHNC 和商业乳膏在治疗中断后 6 天内保持抗痛觉过敏活性。对于机械性痛觉过敏，仅 CHNC 在治疗中断后 48 小时内保持镇痛作用。总之，CHNC 是治疗周围神经性疼痛的一种有前途的制剂。
