In vitro/in vivo evaluation of hydrochlorothiazide in experimental hydrochlorothiazide/triamterene combination tablets in beagle dogs.

Author(s): Ritschel WA, Turkoglu M, Lipps D, Warner A, Sakr A

Affiliation(s): Division of Pharmaceutics and Drug Delivery Systems, College of Pharmacy, University of Cincinnati Medical Center.

Publication date & source: 1991-03, Arzneimittelforschung., 41(3):208-11.

Publication type:

The purpose of this study was to compare experimental formulations containing hydrochlorothiazide (CAS 58-93-5)/triamterene (HCT/TRI) in vitro and in vivo to a commercial tablet formulation (standard). The beagle dog was verified as a good model and was used for the in vivo studies. The commercial tablet and the experimental fast release formulation (FR) resulted in 100% release of HCT within 30 min in dissolution tests, whereas, the slow release formulation (SR) released only 54% HCT after 4 h. Relative bioavailability of the FR and SR formulations were 82 and 41%, respectively, compared to the commercial tablet. The experimental results indicate that HCT absorption occurs throughout the small intestine.