The effect of bendroflumethiazide and hydrochlorothiazide on the rate of dissolution of calcium hydroxyapatite.

Inhibition of dissolution of calcium hydroxyapatite in the presence of bendroflumethiazide, Centyl, and of hydrochlorothiazide has been investigated. The former compound has a pronounced larger inhibitory effect than the latter. The trifluormethyl group in bendroflumethiazide has been shown to hydrolyze, with the release of fluoride and hydrogen ions, presumably forming a carboxylic acid. The inhibitory effect of hydrolyzed bendroflumethiazide is found to be similar to the effect of a potassium fluoride solution with the same fluoride ion concentration, as measured by a fluoride selective ion electrode.