The present invention relates to biocompatible microemulsion systems designed for controlled release drug delivery applications formulated with phospholipids such as lecithin (surfactant), a lipophilic additive (linker) containing 9 or more carbons in their alkyl group and hydrophilic-lipophilic balance (HLB) of 5 or less, and a surfactant-like hydrophilic additive (linker) containing between 6 to 9 carbon atoms in their alkyl tail. The combination of linkers and phospholipids produce formulations capable of delivering high concentrations of poorly soluble drugs into epithelial tissue using low surfactant concentrations, with minimum cytotoxic side effects.
