Table 2.

Prodrug stability in capan-2 cell homogenate with the presence and the absence of inhibitors.

Prodrug	Half Life (min)
	Phosphate Buffer pH 7.4	Capan-2 Cell Homogenate	Cathepsin D Inhibitor	Aminopeptidase Inhibitor	TPP 2 Inhibitor	DPP 3 Inhibitor
5′-O-L-leucyl-L-glycylfloxuridine	23.1 ± 4.1§	3.9 ± 1.1	7.9 ± 0.7	14.0 ± 4.3	5.6 ± 0.6	32.2 ± 9.3
5′-O-L-glycyl-L-leucylfloxuridine	35.7 ± 0.9§	29.2 ± 0.7	32.2 ± 0.1	33.0 ± 0.4	21.0 ± 0.9	26.5 ± 17.5
5′-O-L-valyl-L-phenylalanyl- floxuridine	104.7 ± 7.0§	56.2 ±12.8	76.4 ±6.1	93.6 ± 29.3	46.1 ± 1.9	67.7 ± 15.1
5′-O-L-phenylalanyl-L-tyrosyl- floxuridine	233.9 ± 6.6§	42.8 ± 0.0	105.7 ± 12.8*	54.7 ± 2.8	42.2 ± 1.3	47.2 ± 3.6
5′-O-L-phenylalanyl-L-glycyl- floxuridine	132.1 ± 10.2§	4.3 ± 0.9	10.2 ± 3.0	25.7 ± 0.4*	19.6 ± 0.4*	30.1 ± 10.0
5′-O-L-phenylalanylfloxuridine	187.0 ± 19.0§	3.0 ± 0.1	60.6 ± 4.6*	48.7 ± 0.37*	15.3 ± 0.6*	28.9 ± 10.7

^*<0.01; cathepsin D inhibitor–pepstatin A, aminopeptidase inhibitor–puromycin, TPP2 (tripeptidylpepptidase 2) inhibitor-H-Ala-Ala-Phe-CMK CF₃CO₂H, DPP3 (dipeptidylpeptidase 3)–1,10-phenanthroline. Asterisks indicate significant difference in half lives in capan-2 cell homogenate with an inhibitor to ones without inhibitors. Values presented are the mean ± s.d. (* p < 0.01; t-test).

^§ from Reference [50].