A Central Composite Design Optimized Diclofenac Potassium Loaded Niosomal Gel: Fabrication and Evaluation

Aim: The goal of this study was to create niosomal carriers for delivering diclofenac potassium through the skin, aiming to understand how these niosomal vesicles can improve skin penetration and absorption. Materials and Methods: Niosomes containing diclofenac potassium were prepared using a thin film hydration method. This involved varying the ratios of non-ionic surfactants (span-60 and span-80) with Cholesterol (CHO). We optimized the niosomes using a central composite design, treating the concentrations of span-60, span-80 and cholesterol as independent variables and measuring vesicle size and entrapment efficiency as dependent variables. The optimized niosome batch was then mixed into a 1% carbopol gel and assessed for various properties, including pH, viscosity, extrudability and in vitro release. Results: The vesicle sizes of the formulations ranged from 0.35±0.01 µm to 2.04±0.04 µm. Entrapment Efficiency (% EE) varied from 65.00±0.91% to 86.29±0.12%. Polydispersity Index (PDI) values ranged from 0.352±0.01 to 0.652±0.02. Zeta potential ranged from -47.13±0.71 to -37.09±0.51 mV. The optimized batch showed a particle size of 0.39±0.01 µm and an entrapment efficiency of 86.29±0.12%. The diclofenac potassium niosomes formulated with 40% span 60, 20% span 80 and 20% Cholesterol (CHO) showed promising results and were mixed into a 1% Carbopol gel. The resulting niosomal gel was tested for several physicochemical properties, including pH, viscosity and extrudability. An in vitro drug release study conducted using phosphate-buffered saline at pH 6.8 revealed that 72.01%±1.23 of the drug was released over 10 hr. Conclusion: The study concludes that the gel formulations containing niosomes loaded with Diclofenac Potassium showed prolonged action than formulations containing Diclofenac potassium in non-niosomal form.