SPL Set ID: 94021822-60cb-4da6-b809-f565e1d6452d

Prazosin Hydrochloride Capsules, USP, a quinazoline derivative, is the first of a new chemical class of antihypertensives. It is the hydrochloride salt of 1-(4-amino-6,7-dimethoxy­-2-quinazolinyl)-4-(2-furoyl) piperazine and its structural formula is: Molecular formula C 19 H 21 N 5 O 4 •HCl It is a white, crystalline substance, slightly soluble in water and isotonic saline, and has a molecular weight of 419.87. Each 1 mg capsule of prazosin hydrochloride for oral use contains drug equivalent to 1 mg free base. Inert ingredients in the formulations are: hard gelatin capsules (which may contain alcohol, black iron oxide, butyl alcohol, D&C Red No. 33, D&C Yellow No. 10, FD&C Blue No. 1, FD&C Blue No. 2, FD&C Red No. 40, gelatin, propylene glycol, shellac, titanium dioxide); lactose anhydrous; lactose monohydrate; magnesium stearate; pregelatinized starch 1500. FDA approved dissolution test specifications differ from USP. Chemical Structure