Objective: To investigate the dissolution of L-epicatechin from the ultra-micro and traditional powder of Xanthoceras sorbifolia. Method: HPLC technique was used to detect the content of L-epicatechin. Chromatographic conditions were as follows:Agilent Eclipse-C18 column (4.6 mm×250 mm

5 μm)

detection wavelength 280 nm

mobile phase of acetonitrile-0.04% H3PO4 (15:85)

flow rate 1.0 mL·min-1

injection volume 20 μL. Dissolution amount and the dissolution rate of L-epicatechin from the ultra-micro and traditional powder of X. sorbifolia were determined

and exoteric dissolution behavior was analyzed. Result: Dissolution amount of L-epicatechin from ultra-micro and traditional powder were 5.868 mg·g-1 and 8.440 mg·g-1

respectively. Exoteric dissolution curves were in line with Weibull distribution. T50

Td

T70

T80

T90 of traditional powder were 0.476

1.952

2.939

5.488

9.961 min

respectively

but these of ultra-micro powder were 0.180

0.348

0.469

0.768

1.249 min. The dissolution rate of ultra-micro powder of X. sorbifolia was increased obviously (P<0.01). Per unit of time (1 h) dissolution amount increased by about 44% compared with traditional powder. Conclusion: Superfine grinding can promote the dissolution of L-epicatechin in X. sorbifolia

and application of superfine grinding is feasible and necessary.