TABLE 2

ANS-DMPC binding parameters—namely, binding constant (K), maximum fluorescence intensity (Cmax), and binding cooperativity (b)—upon addition of diclofenac at 37°C as a function of pH value

The values of the binding parameters are presented as the means ± S.D. of two independent assays. The total molar concentration of diclofenac added ([Drug]) and the corresponding membrane concentration ([Drug]m) are also presented.

pH[Drug] (×10−4 M)[Drug]m (×10−2 M)KbCmax
3.0000.08 ± 0.011.40 ± 0.061049 ± 86
4100.076 ± 0.0041.34 ± 0.03880 ± 59
8200.074 ± 0.0061.36 ± 0.01747 ± 63
5.0000.069 ± 0.0011.29 ± 0.051005 ± 50
480.069 ± 0.0031.25 ± 0.02916 ± 34
8160.067 ± 0.0011.27 ± 0.05857 ± 59
7.4000.073 ± 0.0011.33 ± 0.01936 ± 43
460.068 ± 0.0031.25 ± 0.01976 ± 6
8120.074 ± 0.0021.33 ± 0.01938 ± 17