Flucloxacillin is a semisynthetic β-lactam antibiotic belonging to the penicillin class. It is an isoxazolyl penicillin developed to provide resistance to degradation by certain bacterial β-lactamases. Flucloxacillin has the molecular formula C₁₉H₁₇ClFN₃O₅S, molecular weight 453.87 g/mol, and CAS Registry Number 5250-39-5.
Flucloxacillin contains the characteristic β-lactam structure of penicillin antibiotics and has three defined stereocenters. The FDA Global Substance Registration System identifies Flucloxacillin as the active form and separately identifies its sodium and sodium-monohydrate salt forms.
Flucloxacillin is a β-lactam antibacterial compound used in pharmaceutical formulations as an antibacterial active ingredient. Its chemical structure includes a 2-chloro-6-fluorophenyl-substituted isoxazole ring attached to the penicillin nucleus.
For pharmaceutical manufacturing, Flucloxacillin is frequently encountered in its sodium salt form.
Flucloxacillin sodium anhydrous has molecular formula C₁₉H₁₆ClFN₃NaO₅S and molecular weight 475.86 g/mol. FDA identifies its UNII as 05F65O42VK.
Flucloxacillin sodium monohydrate has molecular formula C₁₉H₁₈ClFN₃NaO₆S, molecular weight 493.87 g/mol, and CAS 34214-51-2.
Flucloxacillin is a penicillin-class antibacterial compound used in pharmaceutical products for the treatment of susceptible bacterial infections. Its β-lactam antibacterial activity is associated with interference with bacterial cell-wall synthesis.
As a β-lactam antibiotic, Flucloxacillin acts by binding to bacterial penicillin-binding proteins and interfering with the transpeptidation step required for peptidoglycan cell-wall synthesis. This weakens the bacterial cell wall and leads to bacterial cell death in susceptible organisms.
Flucloxacillin API quality assessment should include appropriate identity, assay, related-substance, moisture and other applicable pharmacopoeial tests.
The exact specification depends on whether the material is Flucloxacillin, Flucloxacillin sodium anhydrous, or Flucloxacillin sodium monohydrate. These should not be treated as interchangeable substances because their molecular weights and water content differ.
Flucloxacillin should be stored in a tightly closed pharmaceutical-grade container under the conditions specified for the particular API grade. β-lactam compounds should be handled using appropriate pharmaceutical and occupational safety controls.
Flucloxacillin API should be packed in suitable pharmaceutical-grade containers that protect the material against contamination, moisture and inappropriate environmental exposure.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.5% |
| Heavy Metals | NMT 20 ppm |
| pH (1% Solution) | 2.0 – 4.0 |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |