Table 2.
Binding parameters of naproxen, warfarin, and digitoxin in various albumin solutions
| Specific binding | Non Specific binding | |||||||||
| n1 | K1 (µmol/L) | n2 | K2 (µmol/L) | |||||||
| Napr. | Warf. | Dig. | Napr. | Warf. | Dig. | Napr. | Warf. | Napr. | Warf. | |
| Human serum | 1.0 (0.1) | 1.1 (0.1) | 1.8 (0.5) | 0.4 (0.4) | 5.1 (1.9) | 56.5 (21.0) | 3.9 (0.2) | 3.7 (0.1) | 11.3 (0.8) | 72.1 (8.2) |
| Sigma albumin | 0.8 (0.1) | 0.9 (0.1) | 1.0 (0.1) | 0.2 (0.1) | 6.3 (1.3) | 30.0 (2.2) | 3.2 (0.2) | 3.9 (0.3) | 16.3 (1.9) | 173.5 (31.2) |
| Baxter/Immuno | 3.3* (0.6) | 1.0 (0.1) | 1.1 (0.1) | 55.2* (10.9) | 25.4* (2.4) | 79.2# (6.9) | 3.8 (0.2) | 3.6 (0.2) | 70.5* (2.0) | 316.3* (27.4) |
| Pharmacia & Upjohn | 3.5* (1.3) | 1.2 (0.1) | 1.4 (0.3) | 66.9* (28.2) | 37.6* (6.4) | 113.0# (33.7) | 3.8 (0.3) | 3.8 (0.3) | 78.5* (9.2) | 342.1* (45.4) |
| Octapharma | 4.5* (0.8) | 1.3 (0.2) | 0.9 (0.03) | 70.0* (14.0) | 39.6* (7.6) | 61.2# (3.1) | 4.0 (0.3) | 3.9 (0.2) | 60.2* (8.4) | 321.1* (42.0) |
The binding studies with naproxen, warfarin, and digitoxin were performed with ultrafiltration of the various albumin solutions containing 0.615 mmol/L albumin. The binding parameters: binding sites, specific (n1) and non-specific (n2) and dissociation constants K1 and K2 were calculated according to Scatchard [17]. The values are means (SDs) of five separate experiments. * p < 0.05 compared with human serum and Sigma albumin. # p < 0.05 compared with Sigma albumin.