PHARMACOKINETICS OF A MORE RELIABLE CHLORAMINOPHENE(R) FORMULATION

The pharmacokinetics of two formulations of chlorambucil, Chloraminoph ene(R) capsules and Chloraminophene(R) tablets, were compared in 12 pa tients in a randomized cross-over study, Chlorambucil concentrations i n plasma were measured by HPLC over a period of 24 h after drug intake , The peak concentration (C-max) occurred earlier after administration of capsules than after administration of tablets [median (range)]: 0. 50 (0.33-0.66)h vs 2.00 (0.66-4.00)h (p < 0.01), Although values of C- max and the area under the plasma concentration versus time curve (AUG ) were not significantly different, the two formulations were not bioe quivalent. Tolerance was in both cases acceptable, with only a transie nt decrease in haemoglobin one day after last drug intake. The variabi lity of chlorambucil pharmacokinetics tended to be less important for capsules than for tablets: 38% vs 71% and 35% vs 113% for C-max and AU C respectively. Capsules are therefore likely to be more reliable than tablets for clinical use.