Box–Behnken design for the development of fluconazole-loaded classical ethosomes

Introduction: Ethosomes are soft and flexible vesicles mainly composed of phospholipids, ethanol and water. The presence of a high amount of ethanol ensure deeper drug penetration; however, an optimal formulation is necessary. This study aims to develop and characterize Fluconazole loaded classical ethosomes using Box-Behken design, in order to achieve to an optimal formulation having a minimal vesicle size, low polydispersity index, high zeta potential and good entrapment efficiency (% EE). Methods: Fluconazole ethosomes were prepared using cold method and tested for vesicle size, polydispersity index, zeta potential and EE%. Box-Behken design was created using Design Expert® Software, where the impact of sonication time and amount of ethanol and soybean lecithin on resulting formulation were investigated. Results: It was determined that increasing the concentration of ethanol up to an optimized limit reduces vesicle size and improves % EE. It was also observed that soybean lecithin concentrations affected positively vesicle size but negatively % EE. Whereas sonication time had an inverse effect both on, vesicle size and EE%. All prepared formulations showed a low polydispersity index and a good zeta potential indicating homogeneity and high stability. Therefore, the optimal formulation had % EE of 80.05±0.306 % and vesicular size of 226.501±5.34 nm with polydispersity index of 0.487±0.0078. Conclusion: In summary, using Box-Behnken design can enhance the understanding of the correlations between the variables involved in ethosome formation and their effects on vesicle size, polydispersity index and % EE. The optimal formulation obtained can be incorporated into drug delivery systems to enhance skin permeation and antifungal activity.