Thiazides. VIII: Dissolution survey of marketed hydrochlorothiazide tablets

The dissolution profiles of 50-mg hydrochlorothiazide tablets representing all approved manufacturers (at the time of the study) were determined in two vehicles [purified water and dilute (1:100) hydrochloric acid] by three methods (rotating basket at 150 rpm; spin filter at 300 rpm; paddle method at 50 rpm). The paddle method was preferred on the basis of overall ease of operation, reproducibility, and discrimination. The paddle data were validated in both vehicles on the same lots of tablets by a second laboratory. A standard of not less than 80% dissolution in 60 min by the paddle method in water is proposed for hydrochlorothiazide tablets.