Formulation and evaluation of topical herbal gel for the treatment of arthritis in animal model

ABSTRACT The objective of the study is to formulate and evaluate a topical herbal gel containing Cardiospermum halicacabum and Vitex negundo leaf extracts for their anti-arthritic activity in rats. Twelve herbal gel formulations were prepared using 1.5% of gelling agents carbopol 934 (F1-F6) and carbopol 940 (F6-F12) and they were evaluated for physical appearance, net content, viscosity, extrudability, pH, spreadability, in vitro diffusion profile and primary skin irritation tests. The stability study for the topical herbal gel formulation was done as per ICH guidelines and anti-arthritic activity was evaluated by Freund's Complete Adjuvant (FCA) induced arthritis method. Assessment of body weight, paw volume, hematological and biochemical parameters, histopathological examination and In vitro determination of serum biomarkers were also carried out. Formulated gels were homogenous, stable and complied with the guidelines. Among the formulations, F4 showed better release (98.4 %) characteristics than other formulations. No erythema or edema was observed in the skin irritation test confirming the gel was non-toxic and safe. Topical application of the herbal gel F4 containing carbopol 934 displayed significant (p < 0.001) anti-arthritic activity compared to diseased rats. Reduction in paw volume, no agglutination in C - reactive protein and rheumatic factor, reduction in TNF level, regaining of normal hematological, and biochemical parameters, reduction in spleen and thymus weight and histopathological examination supported the anti-arthritic activity of the gel formulation.