Topical Delivery of Eberconazole Nitrate Loaded Microemulsion: Formulation, Design and Evaluation

The objective of the present research work was to develop a microemulsion for the transdermal delivery of eberconazole nitrate (EBZ). Initially, oil, surfactant and co-surfactant were selected based on their solubility and emulsification study. A pseudoternary phase diagram was constructed to optimize the surfactant-co surfactant (Smix) ratio. Eberconazole nitrate (EBZ) loaded microemulsion was optimized using central composite design (CCD) with amount of Capmul MCM (X1), tween 80 (X2) and transcutol (X3) as independent variables along with the cumulative amount of drug release (Q24) (Y1), flux (Jss) (Y2) and lag time (tL) (Y3) as dependent variables. Drug release study of all the design batches showed successfully increased permeation of drug which might be due to the compositional characteristics of ME. The globule size of the optimized batch of EBZ loaded ME (153.6 nm) confirms the micrometer size of the formulation. Zeta potential and polydispersity index (PDI) of the optimized batch was found to be -30.5 mV and 0.253, respectively, proving stability and uniform distribution of dispersed systems. The optimized batch of MEs has a pH value of 6.96 ± 0.21, indicating no chance of skin irritation. Further morphological and structural examination of the optimized batch of EBZ loaded ME was done by transmission electron microscope (TEM) and images illustrated the spherical micelles with size range of 100 to 200 nm which evidently may support the high absorption and results into the enhancement of drug permeation which may increase the therapeutic effect, decrease the dose frequency and improving the patience compliance for topical drug delivery.