Ampicillin is an antibiotic used to prevent and treat a number of bacterial infections. This includes respiratory tract infections, urinary tract infections, meningitis, salmonella infections, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously. It is not useful for the treatment of viral infections. Ampicillin was developed in 1961. It is on the World Health Organization's List of Essential Medicines, the most important medication needed in a basic health system. Ampicillin is in the penicillin group of beta-lactam antibiotics and is part of the aminopenicillin family. It is roughly equivalent to amoxicillin in terms of activity. Ampicillin is able to penetrate Gram-positive and some Gram-negative bacteria. It differs from penicillin G, or benzylpenicillin, only by the presence of an amino group. That amino group helps the drug penetrate the outer membrane of Gram-negative bacteria. Ampicillin acts as an irreversible inhibitor of the enzyme transpeptidase, which is needed by bacteria to make their cell walls. It inhibits the third and final stage of bacterial cell wall synthesis in binary fission, which ultimately leads to cell lysis; therefore ampicillin is usually bacteriocidal.
MedKoo Cat#: 317188
Name: Ampicillin
CAS#: 69-53-4 (free acid)
Chemical Formula: C16H19N3O4S
Exact Mass: 349.1096
Molecular Weight: 349.40
Elemental Analysis: C, 55.00; H, 5.48; N, 12.03; O, 18.32; S, 9.18
The following data is based on the product molecular weight 349.40 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.
| Concentration / Solvent Volume / Mass | 1 mg | 5 mg | 10 mg |
|---|---|---|---|
| 1 mM | 1.15 mL | 5.76 mL | 11.51 mL |
| 5 mM | 0.23 mL | 1.15 mL | 2.3 mL |
| 10 mM | 0.12 mL | 0.58 mL | 1.15 mL |
| 50 mM | 0.02 mL | 0.12 mL | 0.23 mL |
