SPL Set ID: 36882c6d-7b6f-41e3-8c54-e3b0073b8c07
1 drug(s) with this SPL Set ID
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 has the molecular formula C 16 H 17 N 3 O 4 S•H 2 O and the molecular weight is 365.41. Cephalexin 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 is a monohydrate. It is a white to off white crystalline powder. Slightly soluble in water, practically insoluble alcohol, in chloroform and in ether. 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 tablet contains cephalexin monohydrate equivalent to 250 mg or 500 mg of cephalexin. The tablets also contain the inactive ingredients: hypromellose, hydroxypropyl cellulose, low-substituted hydroxypropyl cellulose, magnesium stearate, microcrystalline cellulose, silicon dioxide, sodium starch glycolate, talc and titanium dioxide. FDA approved dissolution test specifications differ from USP ceph-structur