Abstract:

In this paper the authors examd. feasible correlations between the structure of different lyotropic mesophases and transdermal administration of three diclofenac derivs. with varying degrees of kosmotropic or chaotropic properties, solubilized within the mesophases. It was found that the most chaotropic deriv. of diclofenac di-Et amine (DEA-DFC) interacted with the polar heads of glycerol monooleate (GMO), thus expanding the water-lipid interface of the lamellar and cubic mesophases. This effect was detected by an increase in the lattice parameter of both mesophases, enhanced elastic properties, and increased solid-like response of the systems in the presence of DEA. Potassium diclofenac (K-DFC), a less chaotropic salt, had less pronounced effect on the structural features of the mesophases. Kosmotropic Na+ salt (Na-DFC) had only minor influence on both lamellar and cubic structures. The locus of solubilization of the mols. with the host mesophases was correlated with their delivery. It was suggested that transdermal delivery of kosmotropic Na-DFC was accelerated by the aq. phase and less constrained by the interaction with monoglyceride. The chaotropic cations (K+ and DEA+), presumably entrapped in the water-lipid interface, interacted with monoglyceride headgroups, which is likely to be the key cause for their sustained administration. [on SciFinder(R)]