Abstract
Purpose. The objective of the study was to investigate the mechanisms behind increased bioavailability of an enzymatically stable thrombin inhibitor, inogatran, after coadministration with a trypsin inhibitor, aprotinin.
Methods. Rat jejunum, ileum and colon segments were stripped and mounted in modified Ussing chambers, and the permeability to inogatran was determined both in the presence and absence of aprotinin. Inogatran and aprotinin were also coadministered intraduodenally to conscious rats. Competitive binding of inogatran to trypsin was studied using kinetic dialysis and was compared to aprotinin. The fraction of free (unbound) trypsin probe, in the absence of trypsin inhibitors was determined by performing experiments without pancreatine and without inhibitors, respectively.
Results. A 3-fold increased permeability to inogatran in the presence of aprotinin was seen in vitro, in some cases correlated with changed barrier properties of the intestinal segments. The in vitro results were well correlated with the in vivo results. There was a 5-fold increase in the bioavailability of inogatran in the presence of aprotinin. The binding of a trypsin probe was inhibited by both the presence of inogatran and aprotinin. Aprotinin showed a several fold higher displacement than inogatran. The results indicate both an effect of aprotinin on the epithelial membrane and an inhibition of binding of the thrombin inhibitor to trypsin or other serine proteases in the gut.
Conclusions. The coadministration of aprotinin with enzymatically stable peptides, like thrombin inhibitors, may improve their absorption after oral administration. This suggests a new additional mechanism for intestinal absorption enhancement of peptide drugs.
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REFERENCES
E. J. van Hoogdalem, A. G. De Boer, and D. D. Breimer. Intestinal drug absorption enhancement. An overview. Pharmac. Ther. 44:407–443 (1989).
S. Muranishi and A. Yamamoto. Mechanisms of absorption enhancement through gastrointestinal epithelium. In: Drug Absorption Enhancement, p. 67–100, ed A. G. De Boer, Harwood Academic Publishers (1994).
J. A. Fix. Strategies for delivery of peptides utilizing absorption-enhancing agents. J. Pharm. Sci. 85:1282–1285 (1996).
S. Fujii, T. Yokoyama, T. Ikegaya, F. Sato, and N. Yokoo. Promoting effect of the new chymotrypsin inhibitor FK-448 on the intestinal absorption of insulin in rats and dogs. J. Pharm. Pharmacol. 37:545–549 (1985).
V. H. L. Lee and A. Yamamoto. Penetration and enzymatic barriers to peptide and protein absorption. Adv. Drug Delivery Rev. 4:171–207 (1989).
V. H. L. Lee., A. Yamamoto, and U. B. Kompella. Mucosal penetration enhancers for facilitation of peptide and protein drug absorption. Crit. Rev. Ther. Drug Carrier Syst. 8:91–192 (1991).
P. P. Constantinides, J.-P. Scalart, C. Lancaster, J. Marcello, G. Marks, H. Ellens, and P. Smith. Formulation and intestinal absorption enhancement evaluation of water-in-oil microemulsions incorporating medium-chain glycerides. Pharm. Res. 11:1385–1390 (1994).
H. L. Luessen, J. C. Verhoef, G. Borchard, C.-M. Lehr, A. G. De Boer, and H. E. Junginger. Mucoadhesive polymers in peroral peptide drug delivery II. Carbomer and polycarbophil are potent inhibitors of the intestinal proteolytic enzyme trypsin. Pharm. Res. 12:1293–1298 (1995).
H. L. Luessen, B. J. de Leeuw, M. W. E. Langemeijer, A. G. De Boer, J. C. Verhoef, and H. E. Junginger. Mucoadhesive polymers in peroral drug delivery. VI. Carbomer and chitosan improve the intestinal absorption of the peptide drug buserelin in vivo. Pharm. Res. 13:1668–1672 (1996).
P. Lundin, S. Lundin, H. Olsson, B. Karlsson, B. Weström, and S. Pierzynowski. Enhanced intestinal absorption of oxytocin peptide analogues in the absence of pancreatic juice in pigs. Pharm. Res. 12:1478–1482 (1995).
U. Eriksson, L. Renberg, U. Bredberg, A.-C. Teger-Nilsson, and C.-G. Regårdh. Animal pharmacokinetics of inogatran, a lowmolecular-weight thrombin inhibitor with potential use as an anti-thrombotic drug. Biopharm. Drug Dispos. 19:55–64 (1998).
H. Lennernäs, S. Nylander, and A.-L. Ungell. Jejunal permeability: A comparison between the Ussing chamber technique and the Single-pass perfusion in humans. Pharm. Res. 14:667–671 (1997).
C. Smith, A. MacInnes, and M. J. Powling. Abstract British society for haemostasis and Thrombosis Nordic Coagulation Group, 1–3, May, London (1996).
A.-L. Ungell, A. Andreasson, K. Lundin, and L. Utter. Effects of enzymatic inhibition and increased paracellular shunting on transport of vasopressin analogues in the rat. J. Pharm. Sci. 81:640–645 (1992).
K. Palm, K. Luhtman, A.-L. Ungell, G. Strandlund, and P. Artursson. Correlation of drug absorption with molecular surface properties. J. Pharm. Sci. 85:32–39 (1996).
R. Griffiths, A. Lewis, and P. Jeffrey. Models of Drug Absorption in Situ and in Concious Animals. In: Models for Assessing Drug Absorption and Metabolism. Eds: R. T. Borchardt, P. L. Smith, and G. Wilson. Plenum press. (1996).
Chromogenix AB, Mölndal, Sweden: Determination of trypsin in duodenal fluid. Laboratory Instruction.
S. Gotoh, R. Nakamura, M. Nishiyama, T. Fujita, A. Yamamoto, and S. Muranishi. Does bacitracin have an absorption-enhancing effect in the intestine? Biol. & Pharmaceut. Bull. 18:794–796 (1995).
S. Gotoh, R. Nakamura, M. Nishiyama, Y.-S. Quan, T. Fujita, A. Yamamoto, and S. Muranishi. Effects of protease inhibitors on the absorption of phenol red and fluorescein isothiocyanate dextrans from the rat intestine. J. Pharm. Sci. 85:858–862 (1996).
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Sjöström, M., Lindfors, L. & Ungell, AL. Inhibition of Binding of an Enzymatically Stable Thrombin Inhibitor to Lumenal Proteases as an Additional Mechanism of Intestinal Absorption Enhancement. Pharm Res 16, 74–79 (1999). https://doi.org/10.1023/A:1018870712463
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DOI: https://doi.org/10.1023/A:1018870712463