Ceftobiprole Medocaril Sodium

Physical and Quality Control Parameters

Appearance: White to off-white crystalline powder, odorless, hygroscopic.

Solubility: Very soluble in water (solubility >100 mg/mL, 25℃), slightly soluble in methanol, practically insoluble in ethanol and acetone; aqueous solution is clear and transparent, pH range 5.0-7.0, suitable for the preparation of intravenous injections.

Stability

Solid form: Sealed, protected from light, and stored at 2-8℃, with a shelf life of 24 months; sensitive to humidity, easily degraded after moisture absorption, requiring vacuum packaging with aluminum-plastic composite film.

Aqueous solution: Stable for 6 hours at room temperature, and stable for 24 hours under refrigeration (2-8℃); avoid mixing with solutions containing heavy metal ions to prevent complexation reactions.

Key Quality Control Indicators (API level)

Chemical Purity: ≥99.0% (HPLC area normalization method, detection wavelength 254 nm)

Related Substances: Single impurity ≤0.1%, total impurities ≤0.5% (HPLC impurity control method)

Moisture Content: ≤3.0% (Karl Fischer method, due to hygroscopicity, rapid volumetric method is used)

Sodium Content: 3.0%-3.5% (Atomic absorption spectrophotometry)

Sterility: Complies with the requirements of the Chinese Pharmacopoeia sterility test method

Bacterial Endotoxin: ≤0.1 EU/mg

III. Pharmacological Effects and Antibacterial Spectrum

1. Mechanism of Action

After intravenous administration of the prodrug ceftobiprole medocaril sodium, it is rapidly hydrolyzed by non-specific esterases in the plasma, removing the 3-(dimethylamino)propionate group to generate the active ingredient ceftobiprole.

Ceftobiprole binds with high affinity to bacterial penicillin-binding proteins (PBPs), especially selectively binding to PBP2a of MRSA and PBP2/3 of Gram-negative bacteria, inhibiting the cross-linking reaction of bacterial cell wall peptidoglycan, leading to cell wall defects, rupture, and death of bacteria. The methoxyimino side chain in the structure confers resistance to hydrolysis by β-lactamases (including ESBLs and AmpC enzymes), resulting in broad-spectrum anti-enzymatic activity.