preparation and evaluation of aceclofenac topical microemulsion

a topical preparation containing aceclofenac was developed using an o/w microemulsion system. isopropyl myristate was chosen as the oil phase as it showed a good solubilising capacity. pseudo-ternary phase diagrams were used to obtain the concentration ranges of the oil, surfactant (labrasol) and co-surfactant (plurol oleique) for microemulsion formation. five different formulations were formulated with various amount of the oil (5-25%), water (10-50%), and the mixture of surfactant and co-surfactant at the ratio of 4 (45-65%). in vitro permeability of aceclofenac from the microemulsions was evaluated using keshary chien diffusion cells with 0.45-µm cellulose acetate membrane. the amount of the aceclofenac permeated was analyzed by hplc and the droplet size and zeta potential of the microemulsions was determined using a zetasizer nano-zs. the mean diameters of the microemulsion droplets approximately ranged between 154 - 434 nm, and the permeability of aceclofenac incorporated into the microemulsion systems was 3 folds higher than that of the marketed formulation. these results indicate that the microemulsion system studied is a promising tool for percutaneous delivery of aceclofenac.