Diltiazem hydrochloride is a calcium ion influx inhibitor (slow channel blocker or calcium antagonist). Chemically, diltiazem hydrochloride is 1,5-benzothiazepin-4(5H)one,3-(acetyloxy)-5-[2-(dimethylamino) ethyl]-2,3-dihydro-2-(4-methoxyphenyl)-, monohydrochloride,(+)-cis-. The chemical structure is:

Diltiazem hydrochloride is a white to off-white crystalline powder with a bitter taste. It is soluble in water, methanol, and chloroform. It has a molecular weight of 450.98. Diltiazem hydrochloride extended-release capsule (once daily dosage) is formulated as a once-a-day extended release capsule containing either 120 mg, 180 mg, 240 mg, or 300 mg diltiazem hydrochloride.

In addition, each capsule contains the following inactive ingredients: acetyltributyl citrate, ammoniomethacrylate copolymer-NF, D & C Red #28, D & C Yellow #10, D & C Yellow #10 Aluminum Lake, ethylcellulose, FD & C Blue #1 Aluminum Lake, FD & C Blue #2 Aluminum Lake, FD & C Red #40, FD & C Red #40 Aluminum Lake, gelatin-NF, magnesium stearate, methacrylic acid copolymer-NF, propylene glycol, polysorbate 80-NF, starch, sucrose, talc USP, and titanium dioxide. The 180 mg and 240 mg capsules contain yellow iron oxide. In addition, the 240 mg capsule also contains black iron oxide and red iron oxide.

For oral administration.

This drug meets USP Drug Release 9.

Last reviewed on RxList: 1/19/2010
This monograph has been modified to include the generic and brand name in many instances.