Assessment of the Anti-Inflammatory Effectiveness of Diclofenac Encapsulated in Chitosan-Coated Lipid Microvesicles in Rats.

Background: Diclofenac (DCF) is a widely used nonsteroidal anti-inflammatory drug (NSAID), but its conventional formulations may have limited efficacy and are associated with adverse effects. This study aimed to evaluate the anti-inflammatory and antioxidant effects of diclofenac encapsulated in chitosan-coated lipid microvesicles (DCF-m) compared to free DCF in a rat model of subacute inflammation. Method: DCF-m was prepared using L-α-phosphatidylcholine and coated with chitosan (CHIT). Subacute inflammation was induced using the cotton pellet granuloma model, and animals were divided into four groups (n = 5): a negative control group without granuloma receiving vehicle (double-distilled water), a control group with granuloma receiving vehicle, a group with granuloma treated with 15 mg/kg of free DCF, and a group with granuloma treated with 15 mg/kg of DCF-m. Results: Both DCF and DCF-m significantly reduced granuloma mass, body weight gain, and serum inflammatory markers compared to the control group with granuloma. Moreover, DCF-m treatment led to a more pronounced reduction in granulomatous inflammation and a greater enhancement of antioxidant enzyme activity than free DCF. Conclusions: These findings suggest that DCF-m exhibits superior anti-inflammatory and antioxidant properties compared to conventional diclofenac in a model of subacute inflammation.