In vivo evaluation of hydrochlorothiazide liquisolid tablets in beagle dogs

This study was carried out to evaluate the absorption characteristics of ex perimentally developed hydrochlorothiazide liquisolid tablets using six mal e beagle dogs. Comparison with reference commercial tablets was made. As no bibliographic data were found for the pharmacokinetic parameters of the dr ug in dogs, an intravenous drug administration was included in the study. T he drug was administered orally as a single 25 mg dose of commercial and li quisolid tablets on two occasions in a randomized two-way crossover design. The pharmacokinetic parameters of the drug post intravenous dosing were re ported for the first time. The results of the oral administration revealed statistically significant differences between the liquisolid and the commer cial tablets in the area under the plasma concentration-time curve, the pea k plasma concentration, and the absolute bioavailability. On the other hand , no significant differences were observed between the two formulations wit h regard to the mean residence time, the mean absorption time, and the rate of absorption. The absolute bioavailability of the drug from the liquisoli d tablets was 15% higher than that from the commercial one. The parametric 90% confidence intervals for the different parameters were higher than the commonly expected intervals for bioequivalency, indicating greater bioavail ability of the liquisolid tablets. (C) 2001 Published by Elsevier Science B .V.