Anti-inflammatory activity of topical nimesulide gel in various experimental models

Objective and Design: The anti-inflammatory activity of topically applied nimesulide gel was compared in different experimental models with that of diclofenac and piroxicam gels. Material: Wistar albino rats of either sex were used. Treatment: In acute models, 50 mg of nimesulide or diclofenac were applied to right hind paws 1 h (carrageenan) or immediately before (formalin) irritant injection (sub-plantar). In adjuvant arthritis, 50 mg of nimesulide, diclofenac or piroxicam were applied daily to injected paws for 14 days. Methods: Paw volume was measured by plethysmograph. Statistical significance was tested with Student's t-test. Results: In the carrageenan paw edema, topical nimesulide gel exhibited similar anti-inflammatory activity to diclofenac gel, and was more effective than diclofenac gel in formalin-paw edema. In both acute (18 h) and chronic (14 d) phases of adjuvant arthritis, nimesulide gel was more effective than diclofenac or piroxicam gels. Conclusion: Topical nimesulide gel possesses higher anti-inflammatory activity than that of diclofenac or piroxicam gels.