Skip to main content

Table 3 Effects of caprylate and/or N-acetyl-DL-tryptophan on naproxen, warfarin, and digitoxin binding

From: Pharmaceutical-grade albumin: impaired drug-binding capacity in vitro

 

n1

K1 (µmol/L)

 

No

C

T

C+T

No

C

T

C+T

Naproxen (n = 5)

Native serum

1.0 (0.1)

5.7* (1.4)

2.6* (0.4)

3.2* (0.6)

0.5 (0.1)

67.9* (19.3)

10.4* (2.1)

49.9* (7.6)

Sigma albumin

0.8 (0.04)

2.4* (0.6)

1.4* (0.1)

2.1* (0.4)

0.1 (0.03)

43.9* (11.5)

6.3* (0.5)

47.8* (11.7)

Warfarin (n = 3)

Native serum

1.6 (0.4)

1.3 (0.1)

1.2 (0.02)

1.0 (0.2)

10.4 (3.4)

20.3 (2.9)

9.4 (0.9)

18.1 (3.2)

Sigma albumin

1.6 (0.2)

1.4 (0.3)

1.4 (0.2)

1.6 (0.1)

11.4 (2.1)

30.9 (7.0)

13.5 (3.1)

47.6 (3.6)

Digitoxin (n = 3)

Native serum

1.6 (0.2)

1.4 (0.4)

1.4 (0.5)

1.2 (0.3)

54.2 (8.1)

68.6 (23.2)

50.1 (28.4)

63.4 (28.4)

Sigma albumin

1.3 (0.1)

1.2 (0.1)

1.0 (0.3)

1.0 (0.2)

41.0 (11.0)

66.8 (14.7)

28.3 (18.3)

57.2 (32.3)

  1. The effects of the stabilisers caprylate (C) and N-acetyl-DL-tryptophan (T) and both (C+T) on naproxen, warfarin, and digitoxin binding were tested with ultrafiltration of human serum and Sigma albumin after addition of the stabilisers and ligands. The results were calculated according to Scatchard [17] and expressed by specific binding sites (n1) and dissociation constants (K1). The final concentrations of caprylate and N-acetyl-DL-tryptophan were each 3.2 and 3.3 mmol/L respectively. The values are means (SDs) of 5 separate experiments with naproxen and 3 with warfarin and digitoxin. *p < 0.05 compared with no stabiliser (No).
Back to article page

BMC Clinical Pharmacology

ISSN: 1472-6904