Ex vivo evaluation of celecoxib release from ionic liquid-based microemulsions and microemulgels for topical applications

Abstract

The aim of this study was to introduce new ionic liquid (IL)-based microemulsions and microemulgels as topical delivery systems for celecoxib. Ex-vivo diffusion of celecoxib loaded in IL-based microemulsions and microemulgels through the rat skin by using Franz diffusion cell was investigated and compared with traditional microemulsions. The investigated systems composed of the same nonionic surfactant/co-surfactant of tween-80/transcutol®P, and different oil phases of [BMIM][PF6], [OMIM][PF6] and isopropyl myristate, for construction of ILs/W and O/W microemulsions. The particle size of the ILs/W and O/W microemulsion systems was determined by DLS method. The ex-vivo release results of ILs/W and O/W formulations, at similar conditions, showed that the celecoxib permeability of the ILs/W formulations is more than that of the O/W formulation, either as microemulsion or as microemulgel. As an interesting result, the celecoxib release percent and release rate from the ILs/W systems was more and faster than the O/W system. The kinetic mechanism for ILs/W systems had followed from first-order model and for O/W systems followed Higuchi zero-order model.