Preparation and the influencing factors of cetirizine hydrochloride microemulsion.

We constructed pseudo-ternary phase diagrams to obtain the area of water-in-oil (w/o) microemulsion formation, prepared cetirizine hydrochloride microemulsion, and evaluated its quality. The w/o microemulsion had been formulated using span80 as surfactant, alcohol as co-surfactant, and oleinic acid as oil. Pseudo-ternary phase diagrams were constructed to evaluate the phase behavior of the w/o microemulsion. The properties, including appearance, particle size, and stability, were determined. The stable w/o microemulsion could be prepared using span80/ alcohol/ oleinic acid/ water (1.2/ 4.8/ 2/ 2). The w/o microemulsion is a new carrier for hydrosoluble drugs, which are easy to prepare with consistent quality.