SPL Set ID: 4e9a8ed3-c490-4a0e-bb29-5eea506f893b

Cephalexin, USP 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, USP has the following structural formula: C 16 H 17 N 3 O 4 S•H 2 O M.W. 365.41 The nucleus of cephalexin, USP 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, USP in water is approximately 4.5 to 5. The crystalline form of cephalexin, USP which is available is a monohydrate. It is a white crystalline solid having a bitter taste. Solubility in water is low at room temperature; 1 or 2 mg/mL may be dissolved readily, but higher concentrations are obtained with increasing difficulty. The cephalosporins differ from penicillins in the structure of the bicyclic ring system. Cephalexin, USP has a D -phenylglycyl group as substituent at the 7-amino position and an unsubstituted methyl group at the 3-position. Each capsule contains cephalexin monohydrate, USP equivalent to 250 mg (720 μmol) or 500 mg (1,439 μmol) of cephalexin. Inactive Ingredients: CAPSULES: magnesium stearate, silicon dioxide, and sodium starch glycolate. Capsule Shell and Print Constituents: black iron oxide, D&C Yellow #10 Aluminum Lake, FD&C Blue #1 Aluminum Lake, FD&C Blue #2 Aluminum Lake, FD&C Red #40 Aluminum Lake, gelatin, pharmaceutical glaze modified in SD-45, silicon dioxide or carboxymethylcellulose sodium, sodium lauryl sulfate, titanium dioxide and may contain propylene glycol. In addition, the 250 mg capsule shell contains yellow iron oxide. After mixing, each 5 mL of cephalexin for oral suspension USP will contain cephalexin monohydrate, USP equivalent to 125 mg (360 μmol) or 250 mg (720 μmol) of cephalexin. Inactive Ingredients: SUSPENSION: FD&C Red #40, cherry mixed fruit flavor (artificial flavors, benzyl alcohol, maltodextrin, and modified corn starch), silicon dioxide, sodium benzoate, sugar (fruit granulated), and xanthan gum. structure