ABSTRACT
<p><b>OBJECTIVE</b>To prepare berberine microemulsion, and to investigate its properities and the absorption character in rat intestine in situ.</p><p><b>METHOD</b>The optimum formulation of the blank microemulsion selected by pseudo tertiary phase diagrams and the berberine microemulsion was prepared based on the blank microemulsion. The viscosity, conductance, refraction rate and particle size of berberine microemulsion were surveyed. An in situ rat perfusion method was used to investigate the intestinal absorption of berberine microemulsion. A UV method for determination of berberine in the intestinal flux was established.</p><p><b>RESULT</b>The viscosity, conductance, refraction rate and particle size of berberine microemulsion were 2.11 cPas, 125.5 microomega, 1.363 and 24.0 nm, respectively. The absorption rate of berberine at the ileum was the best. The absorption of berberine microemulsion at the ileum was significantly higher than that of raw medicine (P < 0.01).</p><p><b>CONCLUSION</b>The microemulsion system might improve the absorption of berberine in the intestinal tract.</p>