バルビツール酸誘導体静注後の家兎血漿濃度のin Vitroデータからの予測

抄録

The plasma concentrations of seven barbiturates from in vitro parameters were predicted in the present study. Elimination rate constant (λ₁) and distribution volume of free drug (λ₁) well correlated to the partition coefficient (P) but also the ratio of protein bound fraction to unbound fraction of drugs (f_b/f_u). In these relations, the regression lines between log λ₁ and log P, log V_f and log P, log λ₁ and log f_b/f_u, and log V_f and log f_b/f_u were obtained. On the bases of these regression lines, the plasma concentrations of seven barbiturates were predicted. In both relations (i.e., for log P and log f_b/f_u), the predicted plasma concentrations well correlated to the observed plasma concentrations. The correlation obtained by the regressions to log f_b/f_u was slightly better than the case obtained by the regressions to log P. This may be due to the fact that f_b/f_u is a physiological parameter in contrast to P which is a physicochemical parameter.