Sinemet CR (Carbidopa / Levodopa) - Description

DESCRIPTION

SINEMET* CR (Carbidopa-Levodopa) is a sustained-release combination of carbidopa and levodopa for the treatment of Parkinson's disease and syndrome.

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*Registered trademark of MERCK & CO., INC.
COPYRIGHT © MERCK & CO., INC., 1996
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Carbidopa, an inhibitor of aromatic amino acid decarboxylation, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 244.3. It is designated chemically as (—)-L-α-hydrazino-α-methyl-β-(3,4-dihydroxybenzene) propanoic acid monohydrate. Its empirical formula is C₁₀H₁₄N₂O₄•H₂O and its structural formula is:

Tablet content is expressed in terms of anhydrous carbidopa, which has a molecular weight of 226.3.

Levodopa, an aromatic amino acid, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 197.2. It is designated chemically as (—)-L-α-amino-β-(3,4-dihydroxybenzene) propanoic acid. Its empirical formula is C₉H₁₁NO₄ and its structural formula is:

SINEMET CR is supplied as sustained-release tablets containing either 50 mg of carbidopa and 200 mg of levodopa, or 25 mg of carbidopa and 100 mg of levodopa. Inactive ingredients: hydroxypropyl cellulose, polyvinylacetate-crotonic acid copolymer, magnesium stearate and red ferric oxide. SINEMET CR 50-200 also contains D&C Yellow 10.

The 50-200 tablet is supplied as an oval, scored, biconvex, compressed tablet that is peach colored. The 25-100 tablet is supplied as an oval, biconvex, compressed tablet that is pink colored. The SINEMET CR tablet is a polymeric-based drug delivery system that controls the release of carbidopa and levodopa as it slowly erodes. SINEMET CR 25-100 is available to facilitate titration and as an alternative to the half-tablet of SINEMET CR 50-200.