Transdermal Microemulsion Delivery Systems for Alcohol-Soluble Species Including Nonderivatized Hormones

Thickened microemulsions are described where hydrophobic liquid droplets are distributed in a continuous hydrophilic liquid phase. In relation to conventional oil-in-water (OIW) microemulsions, the described thickened microemulsions may be thought of as modified oil-in-water (MOIW) microemulsions, where both the "oil" and "water" phases of the microemulsion are modified. The oil phase droplets of the thickened MOIW microemulsion are modified with alcohol and an alcohol-lipid phase thickener and can solubilize alcohol-soluble species, including nonderivatized hormones. Preferably, the modified oil phase droplets of the thickened MOIW microemulsion directly solubilize nonderivatized hormones. The polar continuous "water" phase of the thickened MOIW microemulsion is modified with a continuous phase thickener. The modified oil phase droplets disperse into the modified polar continuous phase of the thickened MOIW microemulsion.