Enhanced serum concentrations of Ara-C using suppositories containing tetrahydrouridine as a deamination inhibitor of Ara-C.

Rectal bioavailability of Ara-C (serum AUC 4 h: 65 micrograms h-1 ml-1) administered in a suppository formulation containing tetrahydrouridine (a deamination inhibitor) and sodium salicylate (an adjuvant) to dogs was better than that from a suppository formulation without tetrahydrouridine (serum AUC 4 h: 18 micrograms h-1 ml-1).