A SINGLE-DOSE COMPARISON OF THE BIOAVAILABILITY OF ALUMINUM FROM 2 FORMULATIONS OF SUCRALPHATE IN NORMAL VOLUNTEERS

The oral bioavailability of aluminium was compared after administratio n of 1 g sucralphate as either a tablet or a suspension (1 g/5 mi) in a crossover study in 16 healthy volunteers. Aluminium levels were dete ctable in all subjects pre-dose (21.4+/-8.8 mu g l(-1) before tablet; 21.4+/-7.4 mu g l(-1) before suspension) and there was a measurable in crease in the plasma concentrations of aluminium in all subjects after administration of the suspension, and in 14 of the subjects after adm inistration of the tablet formulation, with C-max reached within the f irst 8 h in most subjects. Plasma levels were still elevated 72 h afte r dosing. The variability in plasma levels of aluminium was significan tly higher after administration of the suspension (CV 39-53%) than aft er administration of the tablet (CV 29-44%), reflecting greater absorp tion of aluminium from the suspension formulation in three subjects. S imilarly, the variance of the C-max, AUC((0-72 h)), and AUC((0-infinit y)) (for both the raw data and the baseline adjusted data) were all hi gher for the suspension than for the tablet. A point estimate of the d ifference of the pharmacokinetic parameters (determined from the media n of the arithmetic Walsh averages) indicated little or no difference in C-max, T-max, or AUC((0-infinity)) in the two formulations. In summ ary, the performance of the suspension formulation of sucralphate is m ore variable than the tablet formulation in vivo and some patients may therefore have higher circulating levels of aluminium on therapy with the suspension formulation.