β-lactam

Absorption, Distribution and Excretion
Well absorbed after oral administration, independent of food intake.
Approximately 60% to 85% of the drug is excreted unchanged in the urine within 8 hours, the greater portion being excreted within the first 2 hours.

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Metabolism / Metabolites
No appreciable biotransformation in liver (approximately 60% to 85% of the drug is excreted unchanged in the urine within 8 hours).

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Biological Half-Life
0.6-0.9 hour

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Cefaclor is no longer marketed in the United States. Limited information indicates that maternal cefaclor produces low levels in milk which are not expected to cause adverse effects in breastfed infants. Occasionally disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush have been reported with cephalosporins, but these effects have not been adequately evaluated. Cefaclor is acceptable in nursing mothers.
◉ Effects in Breastfed Infants
In a telephone follow-up study, 5 nursing mothers reported taking cefaclor (dosage unspecified). One mother reported diarrhea in her infant. No rashes or candidiasis were reported among the exposed infants.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
23.5%

[1]. Characterization of penicillin-binding protein 2 of Staphylococcus aureus: deacylation reaction and identification of two penicillin-binding peptides. Antimicrob Agents Chemother. 1992 Mar;36(3):656-61.

[2]. Cefaclor revisited. Clin Ther. 2000 Feb;22(2):154-66.

[3]. Pharmacokinetic profile of cefaclor. Int J Clin Pharmacol Ther .

Cefaclor is a cephalosporin bearing chloro and (R)-2-amino-2-phenylacetamido groups at positions 3 and 7, respectively, of the cephem skeleton. It has a role as an antibacterial drug and a drug allergen.
Semisynthetic, broad-spectrum antibiotic derivative of cephalexin.
Cefaclor anhydrous is a Cephalosporin Antibacterial.
Cefaclor is a beta-lactam, second-generation cephalosporin antibiotic with bactericidal activity. Cefaclor binds to and inactivates penicillin-binding proteins (PBP) located in bacterial cytoplasmic membranes. PBPs are enzymes involved in the terminal stages of assembling the bacterial cell wall and in reshaping the cell wall during growth and division. Inactivation of PBPs interferes with the cross-linkage of peptidoglycan chains necessary for bacterial cell wall strength and rigidity. This results in the weakening of the bacterial cell wall and causes cell lysis.
Cefaclor Anhydrous is the anhydrous form of cefaclor, a beta-lactam, second-generation cephalosporin with antibacterial activity. Cefaclor binds to and inactivates penicillin-binding proteins (PBPs) located on the inner membrane of the bacterial cell wall. Inactivation of PBPs interferes with the cross-linkage of peptidoglycan chains necessary for bacterial cell wall strength and rigidity. This results in the weakening of the bacterial cell wall and causes cell lysis.
Semisynthetic, broad-spectrum antibiotic derivative of CEPHALEXIN.

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Drug Indication
For the treatment of certain infections caused by bacteria such as pneumonia and ear, lung, skin, throat, and urinary tract infections.
FDA Label

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Mechanism of Action
Cefaclor, like the penicillins, is a beta-lactam antibiotic. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, it inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins. It is possible that cefaclor interferes with an autolysin inhibitor.

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Pharmacodynamics
Cefaclor is a second generation cephalosporin antibiotic with a spectrum resembling first-generation cephalosporins. In vitro tests demonstrate that the bactericidal action of the cephalosporins results from inhibition of cell-wall synthesis. As indicated by _in vitro_ and _in vivo_ clinical studies, cefaclor was shown to be effective against most strains of Gram positive aerobes - Staphylococci (including coagulase-positive, coagulase-negative, and penicillinase-producing strains), Streptococcus pneumoniae, Streptococcus pyogenes (group A ß-hemolytic streptococci), as well as Gram-negative aerobes - Escherichia coli, Haemophilus influenzae (including ß-lactamase-producing ampicillin-resistant strains), Klebsiella sp, and Proteus mirabilis.

C15H14CLN3O4S

367.81

367.039

C, 48.98; H, 3.84; Cl, 9.64; N, 11.42; O, 17.40; S, 8.72

53994-73-3

Cefaclor monohydrate;70356-03-5;Cefaclor-d5;1426173-90-1

51039

Light yellow to yellow solid powder

1.6±0.1 g/cm3

713.4±60.0 °C at 760 mmHg

385.2±32.9 °C

0.0±2.4 mmHg at 25°C

1.722

0.1

3

6

4

24

606

3

O=C(C(N12)=C(Cl)CS[C@]2([H])[C@H](NC([C@H](N)C3=CC=CC=C3)=O)C1=O)O

QYIYFLOTGYLRGG-GPCCPHFNSA-N

InChI=1S/C15H14ClN3O4S/c16-8-6-24-14-10(13(21)19(14)11(8)15(22)23)18-12(20)9(17)7-4-2-1-3-5-7/h1-5,9-10,14H,6,17H2,(H,18,20)(H,22,23)/t9-,10-,14-/m1/s1

(6R,7R)-7-[[(2R)-2-amino-2-phenylacetyl]amino]-3-chloro-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

S6472; Cefaclor Anhydrous; Ceclor; Lilly 99638; Monohydrate, Cefaclor;Cefaclorum; Cephaclor; Raniclor; Kefral; Cefaclor Monohydrate; Keclor; S 6472; S-6472;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~18.5 mg/mL (~50.30 mM)
H2O : ~3.85 mg/mL (~10.47 mM)

Solubility in Formulation 1: 3.33 mg/mL (9.05 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication (<60°C).

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 (Please use freshly prepared in vivo formulations for optimal results.)