Prazosin hydrochloride, 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)
It has the following molecular formula C19H21N5O4HCl.
It is a white to tan powder, slightly soluble in water and methanol,
very slightly soluble in alcohol, practically insoluble in chloroform
and acetone, and has a molecular weight of 419.87. Each capsule for oral
administration contains prazosin hydrochloride (anhydrous) equivalent
to 1mg, 2mg, or 5mg of prazosin and contains the following inactive ingredients:
Corn Starch, Gelatin, Magnesium Stearate, Sucrose, and Titanium Dioxide.
In addition, the 1mg capsules contain Red 40; the 2mg capsules contain
Blue 1, Red 28 and Red 40; and the 5mg capsules contain Blue 1 and Red