OBJECTIVETo study the solubilization of O/W microemulsion system for volatile oil from Houttuynia Cordra and determine the formulation of its microemulsion.

METHODThe solubilization curve was drawn from pseudo-ternary phase diagram plotted by using the method of titration. The microemulsion's effect on solubilization for volatile oil from Houttuynia Cordra was systematically studied and the difference solubilization effects between colloid fluid and microemulsion were compared.

RESULTExcipient varieties and amount of microemulsion had effects on solubilization for volatile oil from Houttuynia Cordra. The formulation of its microemulsion was determined and we chose medium-chain triglycerides as oil phase, polyoxyethylene castor oil EL-35 as surfactant, propylene glycol as cosurfactant and the surfactant to cosurfactant ratio was 2.

CONCLUSIONSuitable microemulsion formulation can solubilize volatile oil from Houttuynia Cordra and it can provide research foundation for further development of microemulsion preparation for volatile oil from Houttuynia Cordra.