Development and evaluation of a Chinese herbal gel for analgesic and anti-inflammatory effects

This study aimed to develop a film-forming gel containing three Chinese herbal extracts, an extracted mixture of Corydalis yanhusuo, Cynanchum paniculatum and Armadillidium vulgare (Latreille) (MCCA) and evaluate its analgesic and anti-inflammatory activities. Using the Box Behnken Design, the optimal prescription for the MCCA gel was determined. The analgesic effects were tested through acid writhing and formalin pain models. while the rheumatoid arthritis model assessed the pain and anti-inflammatory effects. For the evaluation of the effect of MCCA gels on pro-inflammatory cytokines, as well, Elisa was used. Results showed that the MCCA Gel with 2% mint oil had the highest transdermal volume of 32.57±0.92μg/cm². High doses of MCCA gel were effective in suppressing pain, with a pain inhibition rate of 54.37% during the acetic acid peristaltic test that showed pronounced inhibition in the second phase of the formalin-induced analgesia test. In the rheumatoid arthritis model, the MCCA gel reduced inflammation scores in rat feet and decreased the expressions of four inflammatory factors in serum. Generally, The MCCA gel exhibits noticeable pain-relieving and anti-inflammatory properties with high penetration with the skin.