This study was carried out to evaluate the absorption characteristics of experimentally developed hydrochlorothiazide
liquisolid tablets using six male beagle dogs. Comparison with reference commercial tablets was made. As no
bibliographic data were found for the pharmacokinetic parameters of the drug in dogs, an intravenous drug
administration was included in the study. The drug was administered orally as a single 25 mg dose of commercial and
liquisolid tablets on two occasions in a randomized two-way crossover design. The pharmacokinetic parameters of the
drug post intravenous dosing were reported for the first time. The results of the oral administration revealed
statistically significant differences between the liquisolid and the commercial tablets in the area under the plasma
concentration–time curve, the peak plasma concentration, and the absolute bioavailability. On the other hand, no
significant differences were observed between the two formulations with regard to the mean residence time, the mean
absorption time, and the rate of absorption. The absolute bioavailability of the drug from the liquisolid 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 bioavailability of the
liquisolid tablets.