Abstract
For clinical monitoring drug therapy, saliva is an useful body fluid. However prior to employing saliva for this purpose it is necessary to elucidate the behaviors of drugs in saliva in order to establish adequate methods in detecting drug concentrations. This time the fate of hydralazine (HP) in human saliva was examined. By means of GC and GC/MS, transformation of HP to tetrazolo[5, 1-a] phthalazine (Tetra-P) as a main product in human saliva or in NaNO2-administered rabbit urine was observed under simulated gastric conditions. In acid free saliva, 3-methyl-s-triazolo[3, 4-a] phthalazine (MTP) and s-triazolo[3, 4-a] phthalazine (Tri-P), both derived from acetylated HP, were the main products after incubation at 37℃. The results show that the amounts of the products-MTP, Tri-P and Tetra-P-depend considerably on pH and incubation time. It also should be noted that hydrazine (HZ), a carcinogen as well as a mutagen, was detected as one of the metabolites of HP in rabbit urine. Reaction course for the formation of Tetra-P in human saliva under simulated gastric condition was also discussed.
