Abstract:
Over the past few decades there has been growing interest to develop novel drug delivery systems. These system uses to minimize drug degradation and loss, to prevent harmful side-effects and to increase drug bioavailability and the fraction of the drug accumulated in the required zone, various novel drug delivery systems are currently under development. Among drug carriers one can name non aqueous microemulsions. Conventional emulsions are heterogeneous system in which one immiscible liquid is dispersed as droplets in another liquid. Such a thermodynamically unstable system is kinetically stabilized by addition of one further components that exhibit emulsify properties. In emulsion water is an internal phase dispersed in oil are termed as water-in-oil, whereas, emulsion in which the oil is dispersed and water forms the continuous phase are known as oilin-water emulsions. Emulsion is one of the most convient and advantageous formulation in which one of the liquid phases is water. However emulsion can be formulated without an aqueous phase to produce anhydrous, non-aqueous or oil in oil microemulsions. Such systems, which can replace conventional emulsions where the presence of water to be avoided. The present work was aimed at formulating stable non aqueous emulsions of castor oil and silicone oil, exploring also the possibility of using such systems as anhydrous vehicles for controlled drug release.

Keywords: Non Aqueous Microemulsions, Internal Phase, Thermodynamically Stable System.