TABLE 4

Radioactive plasma concentration of unchanged drug and its total metabolites after oral administration of[¹⁴C]TSU-68 with and without prior oral administration of unlabeled TSU-68 (200 mg/kg/dose)

Each value shown is mean with S.D. (n = 4).

		Plasma Concentration (μg or μg-Eq/ml)^a
Time	Prior Dosing	Total Metabolites	Unchanged Drug	Concentration Ratio (Metabolites/Unchanged Drug)
2 h	(−)	3.3 ± 1.6	17.2 ± 5.5	0.18 ± 0.06
	(+)	6.0 ± 2.3	2.8 ± 1.6^*	2.41 ± 0.81^*
4 h	(−)	7.8 ± 1.7	18.5 ± 1.9	0.42 ± 0.07
	(+)	9.2 ± 2.6	3.8 ± 2.1^*	2.91 ± 1.33^*

↵ a The total amount of the radioactive metabolites in plasma was expressed as μg-Eq of TSU-68/ml.
↵* Significantly different from value without prior dosing (P < 0.05).