Captopril formulation providing increased duration of activity

A tablet for oral administration of captopril consisting essentially of a pH stable core, an enteric or delayed release first coating, and a captopril containing second coating, said pH stable core consisting essentially of on a weight percentage basis from about 5% to about 50% captopril, from about 1% to about 20% of disodium edetate, from about 10% to about 70% of the combination of ascorbic acid and sodium ascorbate, and from about 10% to about 30% of the combination of microcrystalline cellulose, stearic acid, and cornstarch, said enteric or delayed release first coating consisting essentially of a polymeric material selected from the group consisting of methacrylic acid copolymers, ethylcellulose, hydroxypropyl methylcellulose phthalate, cellulose acetate trimellitate, cellulose acetate phthalate, and blends of cellulose acetate trimellitate and cellulose acetate phthalate, a plasticizer selected from the group consisting of acetyltri-n-butyl citrate, triethyl citrate, acetyltriethyl citrate, tri-n-butyl citrate, castor oil, polyethylene glycol, and dibutyl phthalate, and a glidant selected from the group consisting of talc, microfine silicas and metallic stearates, and said second coating consisting essentially of captopril and a water soluble polymer selected from the group consisting of hydroxypropylmethyl cellulose, hydroxypropylcellulose, and blends of hydroxypropylmethyl cellulose and hydroxypropylcellulose