Phase behaviour of microemulsion systems containing short-chain alcohols as co-surfactant

The purpose of this study was to develop several microemulsion (w/o) formulations and to examine the effects of different types of alcohols as co-surfactants. Phase diagrams were constructed at 25°C to investigate the phase behaviour of systems containing water, soy-bean oil, surfactants (S) (Brij 58, Span 80) and co-surfactants (Cos) (ethanol, isopropyl alcohol, 1-butanol, 1-propanol). Comparing the phase diagrams, it was seen that the microemulsion region for all co - surfactants examined was much larger when 1-butanol was used. To investigate the possibility of loading drug in microemulsion systems, diclofenac sodium was employed as a model compound. It was proposed that, microemulsion systems could be used as peroral and topical drug carriers. Therefore, microemulsion formulations containing appropriate amounts of water were suggested as optimal microemulsion formulation for loading hydrophilic drugs and microemulsions containing 6:1 (S/Cos) ratio of ethanol and 4:1(S/Cos) ratio of isopropyl alcohol were selected as the optimal formulations.