The Effect of Grapefruit Juice on the Pharmacokinetics of Tadalafil in Rats

Table 3

Stock solution stability tests for the determination of tadalafil in rat plasma (n = 6).

Storage conditions	Concentration added (ng/mL)	Tadalafil
		RSD (%)	RE (%)
Ambient, 24 h	25	4.19	2.3
	500	2.30	3.1
	1500	1.12	2.7
Three freeze-thaw	25	2.34	−2.4
	500	2.17	3.7
	1500	1.43	−5.4
−80°C, 4 weeks	25	4.03	3.9
	500	2.81	−2.7
	1500	1.21	3.1