Abstract:

The binary phase diagram of GMO/water reveals the formation of two major lyotropic mesophases that have been extensively studied. Adding short-chain alc. (ethanol, propanol and butanol) to a mixt. of various compns. formed one large isotropic micellar phase (the L phase) and two small confined lyotropic regions termed the L3 sponge phase and the QL (micellar cubic). The QL phase is a new mesostructure. It was shown that while the cubic phase is highly viscous the QL phase is fluid and, it displays unique phys. properties. It is fully transparent (not tinted), non-birefringent, and very stable at room temp. (samples were stored for over 8 mo with no phys. changes). The phases were investigated by cryo-TEM, SAXS and self-diffusion NMR. The structure it has primitive cubic symmetry and is discontinuous micellar phases rather than a bicontinuous one. The QL phase was further dispersed in water contg. amphiphilic copolymer (Pluronic 127) to form cubic nanoparticles that we termed micellosomes. The effect of solubilization of water-insol. drugs like, diclofenc (DCF), at different concns. (0.1, 1, 3, and 10 wt%) in the QL phase was investigated by SAXS, rheol. measurements, and NMR (self-diffusion and relaxation) measurements. The rate of percutaneous penetration through rat skin of these structures is significantly higher than that of the com. drug. The compn. that shows the best penetration was QL with 1 wt% DCF. [on SciFinder(R)]