AIMTo explore the intestinal absorption characteristics of lumbrokinase (YJM-I) in the absence or presence of various absorption enhancers and to find the optimum intestinal site for YJM-I absorption.

METHODSThe absorption kinetics and absorption intestinal sites for YJM-I absorption were investigated with the method of diffusion cell in vitro, duodenum bolus injection, recirculating perfusion and in situ duodenum perfusion in vivo.

RESULTSYJM-I could be transported into blood and kept its biological activity across intestinal endothelial membrane after administration via duodenum site, whereas with lower bioavailability. Some of the absorption enhancers were shown good enhancement effects on intestinal absorption of YJM-I in vitro and in situ experiments. The order of enhanced efficiencies of various enhancers on duodenum, ileum and jejunum in vitro permeation experiments were shown as follows: 1% chitosan > 1% SDCh > 1% Na2EDTA > 1% SDS > 1% sodium caprylate > 1% poloxamer > 1% HP-beta-CD. The order of enhanced efficiencies of various enhancers on duodenum absorption of YJM-I in vivo were as follows: 2.5% SDCh > 2.5% Na2EDTA > 2.0% chitosan > 2.5% SDS > 2.5% sodium caprylate > 2.5% Poloxamer > 2.5% HP-beta-CD.

CONCLUSIONThe results indicated that the absorption of YJM-I could be enhanced by various enhancers, and duodenum was the optimum absorption site of YJM-I. Furthermore, bio-adhesive chitosan might be a potential enhancer of intestinal YJM-I absorption.