Isotropic formulations are thermodynamically stable microemulsions possessing lyotropic liquid crystal properties.
[1] They inhabit a state of matter and physical behaviour somewhere between conventional liquids and that of solid crystals.
[2] Isotropic formulations are amphiphillic, exhibiting selective synchronicity with both the water and lipid phases of the substrate to which they are applied.
[4] While it is well established that the skin provides an ideal site for the administration of local and systemic drugs, it presents a formidable barrier to the permeation of most substances.
[5] Isotropic formulations have been used to deliver drugs locally and systemically via the skin appendages, intercellular and transcellular routes.