TABLE 2.
Stern–Volmer quenching constants of the linagliptin‐bovine serum albumin, rabeprazole sodium‐bovine serum albumin, and 1:1 drug‐drug complex‐bovine serum albumin systems at three different temperatures (pH 7.4)
| System | T (K) | 1/T (K–1) | Ksv (L/mol) | kq (×1010 L·mole–1 ·s –1) | r 2 |
|---|---|---|---|---|---|
| LG‐BSA | 298 | 0.0033 | 57.8 | 0.578 | 0.9967 |
| 308 | 0.0032 | 44.5 | 0.445 | 0.9967 | |
| 318 | 0.0031 | 30.8 | 0.308 | 0.9964 | |
| RS‐BSA | 298 | 0.0033 | 37.8 | 0.378 | 0.9853 |
| 308 | 0.0032 | 36.2 | 0.362 | 0.9977 | |
| 318 | 0.0031 | 25.2 | 0.252 | 0.9949 | |
| (LG‐RS)‐BSA | 298 | 0.0033 | 16.2 | 0.162 | 0.9989 |
| 308 | 0.0032 | 9.62 | 0.096 | 0.9962 | |
| 318 | 0.0031 | 6.32 | 0.063 | 0.9995 |
Abbreviations: BSA, bovine serum albumin; LG, linagliptin; RS, rabeprazole sodium.
Note: The Stern–Volmer quenching constants (Ksv ) and quenching rate constants (kq ) were calculated by applying the Stern–Volmer equation. The value of Ksv was found from the slope obtained from the linear regression line of F 0/F versus quencher concentrations, and kq was estimated from the ratio of Stern–Volmer quenching constants and average lifetime of macromolecule (Ksv /τ 0).