Screening the Prescription Microemulsion by Conductivity and the Phase Behavior

OBJECTIVE To study the preparing microemulsion by conductance and pseudo-ternary phase diagram,and to research its phase behavior.METHODS According to conductivity-moisture content graph,a series of pseudo-ternary phase diagram about the system of tween80-labrasol / Gemseal40-oleic acid / anhydrous ethanol / water under the different proportion of surfactant and cosurfactant(Km) accurately,screening microemulsion prescription,evaluating basic performance of microemulsion with electric conductivity,stability,dyeing method,droplet size,studying the phase behavior and structure type of microemulsion system under different Km.RESULTS Along with the increase of water content,the conductivity showed gradual continuous change.When the value of Km was 2:∶1,the conductivity increased sharply with the water content range between 20% to 66.3%,the conductivity increased gently when the water content varied from 66.3% to 74.5%,the conductivity came up to the platform period and then declined while the water content was above 74.5%.Besides,the microemulsion area in pseudo-ternary phase diagram came to the largest at this ratio.Paeonolum-loaded and Tripterygium Glycosides-loaded microemusions were prepared.The microemulsion was stable under high speed centrifuge,electric conductivity,dyeing method,droplet size which was according with the characterization of microemulsion..CONCLUSION Conductivity can be used to determine the structure of microemulsions,and reflect the changes of phase behavior,it can screen microemulsion prescription by pseudo-ternary phase diagram.