TABLE 1

Enzymatic stability of ACV prodrugs in rat plasma and intestinal homogenates

Values are mean ± S.D. (n = 3−6).

Drug	Plasma^a			Intestinal Segments^b
Drug		k_obs ^c	t_1/2	k_obs ^c	t_1/2
	min⁻¹	min	min⁻¹	min
VACV	0.002 ± 0.001	346.5 ± 133.3	0.02 ± 0.001	28.8 ± 1.6
GVACV	0.034 ± 0.009	20.9 ± 5.3	0.04 ± 0.009	17.2 ± 6.4
VVACV	0.13 ± 0.009	5.3 ± 0.3	0.03 ± 0.002	24.5 ± 2.3
VYACV	0.53 ± 0.48	2.1 ± 1.2	—^*
GYACV	—^*		—^*

↵ a Measured using rat plasma.
↵ b Measured using intestinal segments.
↵ c First order rate constant.
↵* No intact prodrug detected after 1 min.