Title: Cefprozil
CAS Registry Number: 92665-29-7 (anhydrous); 121123-17-9 (monohydrate)
CAS Name: (6R,7R)-7-[[(2R)-Amino(4-hydroxyphenyl)acetyll]amino]-8-oxo-3-(1-propenyl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid monohydrate
Additional Names: (6R,7R)-7-[(R)-2-amino-2-(p-hydroxyphenyl)acetamido]-8-oxo-3-propenyl-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid monohydrate
Manufacturers' Codes: BMY-28100-03-800
Trademarks: Cefzil (BMS); Procef (BMS)
Molecular Formula: C18H19N3O5S.H2O
Molecular Weight: 407.44
Percent Composition: C 53.06%, H 5.20%, N 10.31%, O 23.56%, S 7.87%
Literature References: Semisynthetic oral cephalosporin consisting of ~90:10 Z/E isomeric mixture. Prepn and antibacterial activity: H. Hoshi et al., DE 3402642; eidem, US 4520022 (1984, 1985 both to Bristol-Myers); T. Naito et al., J. Antibiot. 40, 991 (1987). Separation of isomers: M. A. Kaplan et al., US 4727070 (1988 to Bristol-Myers). Comparative in vitro antibacterial spectrum and b-lactamase stability: R. N. Jones et al., Diagn. Microbiol. Infect. Dis. 9, 11 (1988). Clinical pharmacokinetics and tissue penetration: R. H. Barbhaiya et al., Antimicrob. Agents Chemother. 34, 1204 (1990). Comparative clinical trials: A. Iravani, ibid. 35, 1940 (1991); A. G. Arguedas et al., Pediatr. Infect. Dis. J. 10, 375 (1991). HPLC determn in plasma and urine: W. C. Shyu et al., Pharm. Res. 8, 992 (1991). Symposium on clinical use: Clin. Infect. Dis. 14, Suppl. 2, S183-S272 (1992).
Derivative Type: Z-Form
CAS Registry Number: 121412-77-9
Manufacturers' Codes: BMY-28100
Properties: Isolated as the hemihydrate, crystals from acetone, mp 218-220° (dec). uv max (pH 7 phosphate buffer): 228, 279 nm (e 12300, 9800).
Melting point: mp 218-220° (dec)
Absorption maximum: uv max (pH 7 phosphate buffer): 228, 279 nm (e 12300, 9800)
Derivative Type: E-Form
CAS Registry Number: 92676-86-3
Manufacturers' Codes: BMY-28167; BBS-1067
Properties: Colorless prisms from methanol, mp 230° (dec). uv max (pH 7 phosphate buffer): 228, 292 nm (e 13000, 16900).
Melting point: mp 230° (dec)
Absorption maximum: uv max (pH 7 phosphate buffer): 228, 292 nm (e 13000, 16900)
Therap-Cat: Antibacterial.
Keywords: Antibacterial (Antibiotics); ?Lactams; Cephalosporins.
Cefquinome Cefroxadine Cefsulodin Cefteram Ceftezole

Systematic (IUPAC) name
7-[2-amino-2-(4-hydroxyphenyl)-acetyl]amino-8-oxo-3-prop-1-enyl-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid
Clinical data
Trade names Cefzil
AHFS/Drugs.com monograph
MedlinePlus a698022
Licence data US FDA:link
Pregnancy cat. B (US)
Legal status -only (US)
Routes Oral
Pharmacokinetic data
Bioavailability 95%
Protein binding 36%
Half-life 1.3 hours
CAS number 92665-29-7 YesY
ATC code J01DC10
PubChem CID 9887643
DrugBank DB01150
ChemSpider 8063315 YesY
UNII 1M698F4H4E YesY
KEGG D07651 YesY
Chemical data
Formula C18H19N3O5S 
Mol. mass 389.427 g/mol
 N (what is this?)  (verify)

Cefprozil, sometimes spelled cefproxil and marketed under the trade name Cefzil, is a second-generation cephalosporin type antibiotic. In Europe it is marketed using the trade names Procef and Cronocef.[citation needed] It can be used to treat bronchitis, ear infections, skin infections, and other bacterial infections.[citation needed] It comes as a tablet and as a liquid suspension.

Although there is a widely quoted cross-allergy risk of 10% between cephalosporins and penicillin, an article in the Journal of Family Practice[1] has shown no increased risk for cross-allergy for cefprozil and several other second-generation or later cephalosporins.