Chlorothiazide occurs as a white, crystalline powder which can be formulated in tablets or suspension for use as an oral diuretic. It is very slightly soluble in water and is soluble but unstable in alkaline solutions. The solid sodium salt is stable and can be dissolved in water for injection to give a suitable intravenous dosage form. Chlorothiazide's absorption maximum at 292 mμ in 0.1 N sodium hydroxide can be used for analysis of all dosage forms.