SPL Set ID: e46059e1-3ce9-4a3c-80ce-464b140600ce

Cephalexin tablets, USP contain the active ingredient cephalexin, which is a semisynthetic cephalosporin antibiotic intended for oral administration. It is 7-(D-α-amino-α-phenylacetamido)-3-methyl-3-cephem-4-carboxylic acid, monohydrate. Cephalexin monohydrate, USP has the molecular formula C 16 H 17 N 3 O 4 S•H 2 O and the molecular weight is 365.40. Cephalexin monohydrate, USP has the following structural formula: The nucleus of cephalexin is related to that of other cephalosporin antibiotics. The compound is a zwitterion; i.e., the molecule contains both a basic and an acidic group. The isoelectric point of cephalexin in water is approximately 4.5 to 5. The crystalline form of cephalexin which is available as a monohydrate. It is a white to almost white powder with granules. Slightly soluble in water, practically insoluble in alcohol, chloroform and in ether. It dissolves in dilute solutions of acids and alkali hydroxides. The cephalosporins differ from penicillins in the structure of the bicyclic ring system. Cephalexin has a D-phenylglycyl group as substituent at the 7-amino position and an unsubstituted methyl group at the 3-position. Each film-coated tablet contains cephalexin monohydrate USP equivalent to 250 mg or 500 mg of cephalexin. The tablet also contains colloidal silicon dioxide, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, sodium starch glycolate, and titanium dioxide. FDA approved dissolution test specifications differ from USP. str