OBJECTIVETo prepare the gel of Chinese medicine catechu,study its release mechanism in vitro and observe the anti-inflammatory activity in rats.

METHODUsing the amount of catechin and epicatechin in dry extract as major evaluation factors, orthogonal experiment was carried out to investigate four influential factors of the ethanol concentration, ratio of raw material to solvent, ultrasonic time and extraction temperature. The catechu gel was prepared by using carbomer-940 as the gel base, and triethanomine as neutralizer. The experiments on drug-releasing profiles in vitro and the phamacodynamics studies on the anti-inflammatory in rats were carried out, respectively.

RESULTThe optimum condition of extraction from catechu was as follows, the concentration of ethanol, ratio of raw material to solvent, ultrasonic time, and extraction temperature were 50% , 1: 12, 35 min and 60 degrees C, respectively. The formulation of catechu gel was carbomer-9 400.5 g, glycerol 5.0 g, the extracts of catechu 50.0 mL, and triethanomine 0.5 mL The gel was semitransparent and stable. The drugs released quickly. The catechu gel reduced the paw edema considerably in dose-dependent manner compared to carrageenan-induced rat.

CONCLUSIONThe formulation of the catechu gel is reasonable, and it shows remarkable anti-inflammatory activity. It is worth doing further research.