Bioavailability of hydrochlorothiazide from isomalt-based moulded tablets

The bioavailability of hydrochlorothiazide (HCT) from moulded isomalt-based tablets was evaluated after oral administration of 50 mg HCT to healthy volunteers as an oral moulded tablet and as a lozenge, in comparison with a conventional tablet formulation (Dichlotride(R) 50 mg). Moulded tablets had a high relative bioavailability (F-rel) as the pharmacokinetic parameters (C-max, t(max), t(1/2), AUC(0-->24 h)) determined from HCT plasma concentration versus time profiles were not significantly different (P > 0.05; two-way ANOVA) in comparison with the conventional tablet. The relative bioavailability of the moulded tablet administered as a lozenge and as an oral tablet was 106.2 +/- 30.9% and 89.4 +/- 25.9%, respectively, in relation to the conventional tablet formulation. Direct moulding of isomalt tablets proved to be a suitable technique to administer a poorly soluble drug either as a conventional tablet or as a lozenge. (C) 2002 Elsevier Science B.V. All rights reserved.