DUAL DRUG-LOADED NIOSOMAL GEL OF LICOFELONE AND SPIRAMYCIN: FORMULATION AND EVALUATION

The present study focused on the development and evaluation of a dual drug-loaded niosomal gel for the topical delivery of Licofelone and Spiramycin. The optimized formulation (F5) exhibited a particle size of 136.7 ± 8.37 nm, a low polydispersity index (PDI) of 0.316 ± 0.92, and a zeta potential of –20.9 mV, indicating uniformity and good colloidal stability. Entrapment efficiency was found to be 70.8 ± 0.55%, attributed to the optimal balance of surfactant and cholesterol concentration. Transmission electron microscopy (TEM) confirmed spherical vesicle morphology with no aggregation. In vitro drug release studies showed a sustained release pattern, achieving 94.19% cumulative release over 24 hours, compared to 26.25% release from the plain gel. Rheological characterization revealed a viscosity of 11,924 ± 1.051 cp and spreadability of 3.6 ± 0.256 cm, allowing for effective topical application and retention. Pharmacodynamic evaluation using the carrageenan-induced paw edema model demonstrated 95.7% inhibition of edema at 24 h when the formulation was applied 12 hours after induction, surpassing the marketed diclofenac gel, which achieved 93.5% inhibition. Stability studies over 90 days indicated excellent stability at 2–8 °C, with particle size changing minimally from 137.5 ± 0.436 nm to 139.9 ± 0.963 nm, while room temperature led to greater instability. Skin irritation studies confirmed no erythema or allergic reaction. Overall, the dual drug-loaded niosomal gel exhibited sustained release, enhanced anti-inflammatory activity, favorable rheological properties, excellent stability, and dermal safety, positioning it as a promising future platform for effective and patient-compliant topical therapy in inflammatory and infectious skin disorders.