*Gazi University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 06330 Etıler, Ankara, TURKEY.
**İ.E. Ulagay, Davutpaşa Caddesi, No:12,34473, Topkapı, Istanbul, TURKEY.
oCorresponding Author

Summary:
Recently, much attentıon has been paid to potential pharmaceutical uses of microemulsions as novel drug delivery systems. Mıcroemulsions are defıned as microcomponent systems consisting a unique ratıo of component including a lipophilic phase, a hydrophylic phase, a surfactant and co-surfactant.The properties of this systems are low viscosity, transparent, thermodynamically stable and droplet diameter less than 140 nm. Such systems are formed spontaneously. Microemulsions are potential drug carrier systems for oral, topical and parenteral administration. Especially, these dosage forms have been recently suggested as carriers for peroral peptide drugs. The use of microemulsions as possible therapeutic system is interesting for controlled drug release and increased systemic and topical absorption of drugs. The structure and characteristics of microemulsion and the use of these systems in pharmaceutical field will be discussed in this review.