Objective:To prepare colon-targetting tablets containing total alkaloids of Sophora alopecuroides and evaluate sophoridine release profiles in vitro.Method:Wet granulation technique was employed to prepare guar-based matrix tablets

optimizing the formula by drug release studies in successive different mimicking media in vitro.Result:These results indicated that the granulations of various formulations showed good flow characteristics

hence

good compressibility.The granulation of formulation A was more fragile

with the increase of the amount of guar

while the granulations of formulation B-D became less fragile.At compression force of 25 kN

the hardness of formula-tion C was maximal

probably due to better proportion of the fine fraction and coarse fraction of the granula.The guar-based matrix tablets released 13.5% to 25.6% of sophoridine in the first 6 h

and released rapidly 55.4% ～ 75.1% in SCF for the first 6 h.Bilayer matrix tablet met required physical properties

its initial release was lagging.Within first 6 h

there was only 6.78% released from matrix tablet

and almost no drug released within 2 h

and the guar ma-trix completely dissolved in 24 h.Dissolution data of various formulations was fit best to Higuichi model

and its re-lease mechanism belonged to bulk erosion.Conclusion:Total alkaloids of S.alopecuroides colon-site targetting tablets could deliver total alkaloids of S.alopecuroides to desire site and its preparation is reasonable.