Micro-emulsion based emulgel: a novel topical drug delivery system

Topical delivery systems for drugs make localized administration of the drug anywhere in the body through ophthalmic, vaginal, skin and rectal routes. Topical formulations encompass a wide variety of formulations intended for cosmetic or dermatological application, to healthy as well as diseased skin. Drugs may be administered for localized or systemic effect. Topical preparations can be formulated with varying physico-chemical properties, as solid, semisolid or liquid. Micro-emulsion of drug is prepared and incorporated into emulgel, having novel topical drug delivery system as dual release control system. Micro-emulsions are micronized; thermodynamically stable systems having low interfacial tension prepared by adding co-surfactant have several features like enhanced permeability, good thermodynemic stability and prolong release. Emulgel prolongs the drug release, increases patient compliance and stability of emulsion. The prepared emulgel is evaluated for various parameteres like pH, viscosity, globule size; spreadability etc. whereas micro-emulsion is evaluated for various parameters like viscosity, pH, zeta-potential etc.