Enhanced oral bioavailability of puerarin using microemulsion vehicle.

The main purpose of this study was to prepare puerarin microemulsion system to improve oral bioavailability of puerarin. The microemulsion formulations were prepared using soybean oil, soybean lecithin/ethyl lactate (1:1), and 1,2-propanediol/water. The presence of microemulsion regions were investigated by pseudo-ternary phase diagrams. The droplet size of microemulsion was characterized by photo-correlation spectroscopy. In vivo pharmacokinetic study was conducted in mice, and the results indicated that AUC(0-->infinity) was 15.82-fold higher than that of puerarin suspension upon oral administration. Particles of puerarin microemulsion were round and homogeneous. Puerarin microemulsion also showed good stability. These studies showed that microemulsion system of puerarin might be promising vehicles for the peroral delivery of puerarin.