Pharmacokinetic evaluation of an oral tablet form of low-molecular-weight heparin and deoxycholic acid conjugate as a novel oral anticoagulant

Summary

This study was designed to develop a solid oral dosage form of deoxycholic acid (DOCA)-conjugated low-molecular-weight heparin (LMWH) and to evaluate its oral absorption, distribution, and metabolic stability for the prospect of providing an orally bioavailable LMWH. The LMWH derivative (LHD) was synthesised and then formulated with solubilisers and other pharmaceutical excipients to form a solid tablet. Its absorption and distribution after oral administration were evaluated in mice, rats, and monkeys. The in vitro metabolic stability of LHD was examined by liver microsome assays. More than 80% of LHD was released from the tablet within 60 minutes, guaranteeing rapid tablet disintegration after oral administration. Oral bioavailability of LHD in mice, rats and monkeys were 16.1 ± 3.0, 15.6 ± 6.1, and 15.8 ± 2.5%, respectively. After the oral administration of ¹³¹I-tyramine-LHD, most of the absorbed drug remained in the blood circulation and was eliminated mainly through the kidneys. LHD was hardly metabolised by the liver microsomes and showed a stable metabolic pattern similar to that of LMWH. In a rat thrombosis model, 10 mg/kg of orally administered LHD reduced thrombus formation by 60.8%, which was comparable to the antithrombotic effect of the subcutaneously injected LMWH (100 IU/ kg). Solid tablets of LHD exhibited high oral absorption and statistically significant therapeutic effects in preventing venous thromboembolism. Accordingly, LHD tablets are expected to satisfy the unmet medical need for an oral heparin-based anticoagulant as an alternative to injectable heparin and oral warfarin.

Keywords

Low-molecular-weight heparin - deoxycholic acid - oral delivery - anticoagulants - solid dosage form

• References

• 1 Weitz JI. Low-molecular-weight heparins. N Engl J Med 1997; 337: 688-698.
• 2 Gray E, Mulloy B, Barrowcliffe TW. Heparin and low-molecular-weight heparin. Thromb Haemost 2008; 99: 807-818.
• 3 Gallus AS. Anticoagulants in the prevention of venous thromboembolism. Bail-lieres Clin Haematol 1990; 3: 651-684.
• 4 Jack H, Sonia SA, Jonathan LH. et al. Guide to anticoagulant therapy: heparin. Circulation 2001; 103: 2994-3018.
• 5 Hull R, Delmore T, Carter C. et al. Adjusted subcutaneous heparin versus warfarin sodium in the long-term treatment of venous thrombosis. N Engl J Med 1982; 306: 189-194.
• 6 Hull RD. Treatment of pulmonary embolism: the use of low-molecular weight heparin in the inpatient and outpatient settings. Thromb Haemost 2008; 99: 502-510.
• 7 Amin AN, Lin J, Lenhart G. et al. Clinical and economic outcomes in patients at risk of venous thromboembolism receiving appropriate enoxaparin or unfractionated heparin prophylaxis. Thromb Haemost 2009; 102: 321-326.
• 8 Dal Pozzo A, Acquasaliente M, Geron MR. New heparin complexes active by intestinal absorption: I-multiple ion pairs with basic organic compounds. Thromb Res 1989; 56: 119-124.
• 9 Malkov D, Wang HZ, Dinh S. et al. Pathway of oral absorption of heparin with sodium N-[8-(2-hydroxybezoyl) amino] caprylate. Pharm Res 2002; 19: 1180-1184.
• 10 Kim SK, Lee EH, Vaishali B. et al. Tricaprylin microemulsion for oral delivery of low molecular weight heparin conjugates. J Control Release 2005; 105: 32-42.
• 11 Andersson M, Lofroth JE. Small particles of a heparin/chitosan complex prepared from a pharmaceutically acceptable microemulsion. Int J Pharm 2003; 257: 305-309.
• 12 Jiao Y, Ubrich N, Marchand-Arvier M. et al. In vitro and in vivo evaluation of oral heparin-loaded polymeric nanoparticles in rabbits. Circulation 2002; 105: 230-235.
• 13 Hoffart V, Lamprecht A, Maincent P. et al. Oral bioavailability of a low molecular weight heparin using a polymeric delivery system. J Control Release 2006; 113: 38-42.
• 14 Dufresne MH, Leroux JC. Study of the micellization behavior of different order amino block copolymers with heparin. Pharm Res 2004; 21: 160-169.
• 15 Ueno M, Nakasaki T, Horikoshi I. et al. Oral administration of liposomally-entrapped heparin to beagle dogs. Chem Pharm Bull (Tokyo) 1982; 30: 2245-2247.
• 16 Hayes PY, Ross BP, Thomas BG. et al. Polycationic lipophilic-core dendrons as penetration enhancers for the oral administration of low molecular weight heparin. Bioorg Med Chem 2006; 14: 143-152.
• 17 Ito Y, Kusawake T, Rama Prasad YV. et al. Preparation and evaluation of oral solid heparin using emulsifier and adsorbent for in vitro and in vivo studies. Int J Pharm 2006; 317: 114-119.
• 18 Kast CE, Guggi D, Langoth N. et al. Development and in vivo evaluation of an oral delivery system for low molecular weight heparin based on thiolated polycarbo-phil. Pharm Res 2003; 20: 931-936.
• 19 Bernkop-Schnürch A, Kast CE, Guggi D. Permeation enhancing polymers in oral delivery of hydrophilic macromolecules: thiomer/GSH systems. J Control Release 2003; 93: 95-103.
• 20 Thanou M, Nihot MT, Jansen M. et al. Mono-N-carboxymethyl chitosan (MCC), a polyampholytic chitosan derivative, enhances the intestinal absorption of low molecular weight heparin across intestinal epithelia in vitro and in vivo. J Pharm Sci 2001; 90: 38-46.
• 21 Thanou M, Henderson S, Kydonieus A. et al. N-sulfonato-N,O-carboxymethylchitosan: A novel polymeric absorption enhancer for the oral delivery of macromolecules. J Control Release 2007; 117: 171-178.
• 22 Windsor E, Cronheim GE. Gastrointestinal absorption of heparin and synthetic heparinoids. Naturwissenschaften 1961; 190: 263-264.
• 23 Rivera TM, Leone-Bay A, Paton DR. et al. Oral delivery of heparin in combination with sodium N-[8-(2-hydroxybezoyl)amino]caprylate: pharmacological considerations. Pharm Res 1997; 14: 1830-1834.
• 24 Gonze MD, Salartash K, Sternbergh III WC. et al. Orally administered unfractionated heparin with carrier agent is therapeutic for deep venous thrombosis. Circulation 2000; 101: 2658-2661.
• 25 Berkowitz SD, Marder VJ, Kosutic G. et al. Oral heparin administration with a novel drug delivery agent (SNAC) in healthy volunteers and patients undergoing elective hip arthroplasty. J Thromb Haemost 2003; 1: 1914-1919.
• 26 Pineo G, Hull R, Marder V. Oral delivery of heparin: SNAC and related formulations. Best Pract Res Clin Haematol 2004; 17: 153-160.
• 27 Mousa SA, Zhang F, Aljada A. et al. Pharmacokinetics and pharmacodynamics of oral heparin solid dosage form in healthy human subjects. J Clin Pharmacol 2007; 47: 1508-1520.
• 28 Lee YK, Nam JH, Shin HC. et al. Conjugation of low-molecular-weight heparin and deoxycholic acid for the development of a new oral anticoagulant agent. Circulation 2001; 104: 3116-3120.
• 29 Kim SK, Lee DY, Kim CY. et al. A newly developed oral heparin derivative for deep vein thrombosis: non-human primate study. J Control Release 2007; 123: 155-163.
• 30 Lee YK, Kim SH, Byun Y. Oral delivery of new heparin derivatives in rats. Pharm Res 2000; 17: 1259-1264.
• 31 Fini A, Fazio G, Roda A. et al. Basic cholane derivatives. XI: comparison between acid and basic derivatives. J Pharm Sci 1992; 81: 726-730.
• 32 Sundaram M, Qi Y, Shriver Z. et al. Rational design of low-molecular weight heparins with improved in vivo activity. PNAS 2003; 100: 651-656.
• 33 Kim SK, Lee DY, Kim C. et al. Prevention effect of orally active heparin derivative on deep vein thrombosis. Thromb Haemost 2006; 96: 149-153.
• 34 Zeymer U, Gitt A, Junger C. et al. Efficacy and safety of enoxaparin in unselected patients with ST segment elevation myocardial infarction. Thromb Haemost 2008; 99: 150-154.
• 35 De Luca G, Marino P. Advances in antithrombotic therapy as adjunct to reperfusion therapies for ST-segment elevation myocardial infarction. Thromb Haemost 2008; 100: 184-195.
• 36 van Doormaal FF, Raskob GE, Davidson BL. et al. Treatment of venous thromboembolism in patients with cancer: subgroup analysis of the Matisse clinical trials. Thromb Haemost 2009; 101: 762-769.
• 37 Traby L, Kaider A, Schmid R. et al. The effect of low-molecular-weight heparin at two different dosages on thrombin generation in cancer patients. Thromb Haemost 2010; 104: 92-99.
• 38 Laux V, Perzborn E, Heitmeier S. et al. Direct inhibitors of coagulation proteins – the end of the heparin and low-molecular-weight heparin era for anticoagulant therapy?. Thromb Haemost 2009; 102: 892-899.
• 39 Hiebert LM, Ping T, Wice SM. Enhanced antithrombotic effects of unfractionated heparin in rats after repeated oral doses and its relationship to endothelial heparin concentration. Br J Pharmacol 2008; 153: 1177-1184.
• 40 Moazed B, Hiebert LM. Movement of heparin across rat gastric mucosa is dependent on molecular weight and pH. Pharm Res 2009; 26: 189-195.
• 41 Javot L, Sapin A, Scala-Bertola J. et al. Oral administration of a microencapsulated low-molecular-weight heparin to rabbits: Anti-Xa and anti-IIa profiles. Thromb Haemost 2010; 103: 1254-1267.
• 42 Kim SK, Kim K, Lee S. et al. Evaluation of absorption of heparin-DOCA conjugates on the intestinal wall using a surface Plasmon resonance. J Pharm Biomed Anal 2005; 39: 861-870.
• 43 Kim SK, Lee DY, Lee EH. et al. Absorption study of deoxycholic acid-heparin conjugate as a new form of oral anticoagulant. J Control Release 2007; 120: 4-10.
• 44 Lee YK, Kim SK, Lee DY. et al. Efficacy of orally active chemical conjugate of low molecular weight heparin and deoxycholic acid in rats, mice and monkeys. J Control Release 2006; 111: 290-298.
• 45 Linhart NC, Laforest MD, Guiraud-Vitaux F. et al. Pharmacokinetics and tissue distribution of ^99mTc-labelled enoxaparin in the rat: evaluation of dosimetry parameters. Biomed Pharmacother 1990; 44: 317-323.
• 46 Frydman A. Low-molecular-weight heparins: an overview of their pharmacodynamics, pharmacokinetics and metabolism in humans. Haemostasis 1996; 26: 24-28.
• 47 McAllister BM, Demis DJ. Heparin metabolism: isolated and characterization of uroheparin. Nature 1966; 212: 293-294.
• 48 Dawes J, Pepper DS. Catabolism of low-dose heparin in man. Thromb Res 1979; 14: 845-860.