The present invention provides pharmaceutical compositions for oral administration comprising a therapeutically effective amount of a selective factor Xa inhibitor or a pharmaceutically acceptable salt thereof and an enhancer, wherein the enhancer is a medium chain fatty acid or a salt, ester, ether, or derivative of a medium chain fatty acid and has a carbon chain length of from about 4 to about 20 carbon atoms. The present invention also provides a method for obtaining a reproducible bioavailability of selective factor Xa inhibitor in an object after oral administration comprising orally administering a pharmaceutical composition as described above.
