Panipenem API is a broad-spectrum carbapenem antibiotic used as an active pharmaceutical ingredient for parenteral antibacterial formulations. Panipenem belongs to the β-lactam antibiotic class and has activity against a broad range of Gram-positive and Gram-negative microorganisms. Its chemical identity is established as Panipenem, with CAS Number 87726-17-8, molecular formula C₁₅H₂₁N₃O₄S, and molecular weight 339.41 g/mol. The compound is officially listed in the Japanese Pharmacopoeia.
Panipenem is particularly notable because it is used in combination with betamipron, an organic anion transport inhibitor. This combination is known as Panipenem/Betamipron or PAPM/BP. Betamipron reduces renal tubular uptake of panipenem and is used to help reduce the potential for renal toxicity associated with panipenem exposure. The combination has been used clinically in Japan and other Asian markets for serious bacterial infections.
The official JP monograph describes Panipenem as a white to light yellow crystalline powder or mass. It is very soluble in water, freely soluble in methanol, slightly soluble in ethanol (99.5), and practically insoluble in diethyl ether. The material is also described as hygroscopic and deliquescent in the presence of moisture, making moisture protection an important consideration during storage and handling.
Panipenem is a carbapenem antibiotic. Carbapenems are β-lactam antibiotics characterized by a broad antibacterial spectrum and strong activity against many clinically important Gram-positive and Gram-negative bacteria.
Panipenem inhibits bacterial cell-wall synthesis by binding to penicillin-binding proteins (PBPs). This interferes with peptidoglycan cross-linking and weakens the bacterial cell wall, ultimately producing a bactericidal effect in susceptible organisms.
The antibacterial activity of Panipenem results primarily from inhibition of bacterial cell-wall synthesis. Following interaction with PBPs, Panipenem interferes with the final stages of peptidoglycan synthesis required for maintaining bacterial cell-wall integrity.
Panipenem is susceptible to renal degradation and tubular handling similar to other carbapenem antibiotics. Therefore, its pharmaceutical combination with betamipron is an important characteristic of the marketed Panipenem formulation. Betamipron inhibits renal tubular uptake of panipenem and helps reduce renal exposure.
Panipenem Pharmaceutical API is primarily associated with injectable antibacterial formulations. Panipenem/betamipron has been used for a range of serious bacterial infections, including respiratory, urinary, surgical, gynecological and other systemic infections. Japanese clinical references describe its use in conditions including sepsis, infective endocarditis, deep-seated skin infections, pneumonia, lung abscess, pyothorax, urinary tract infections, intra-abdominal infections and several gynecological infections.
The Japanese Pharmacopoeia separately recognizes Panipenem as the active carbapenem substance and Panipenem and Betamipron for Injection as the combination dosage form. The official Japanese Pharmacopoeia database specifies that the combination contains Panipenem corresponding to 90.0–105.0% of the labeled potency and Betamipron corresponding to 95.0–105.0% of the labeled amount.
Panipenem has an established Japanese Pharmacopoeia monograph. The current JP monograph specifies the drug substance on a potency basis rather than using a conventional percentage HPLC assay. Panipenem must contain not less than 900 µg and not more than 1010 µg potency per mg, calculated on the anhydrous and residual-solvent-free basis.
The JP monograph also establishes controls for water, residue on ignition, heavy metals, related substances, optical rotation, pH and solution clarity. This makes the JP specification particularly useful for pharmaceutical-grade Panipenem API quality control.
Identification of Panipenem can be established using multiple orthogonal techniques. The JP monograph includes chemical identification, UV-visible spectroscopy and infrared spectroscopy. The official monograph also specifies optical rotation and chromatographic testing for related substances.
For related substances, the JP method uses liquid chromatography with UV detection at 220 nm. The current monograph specifies that an individual peak other than Panipenem must not exceed 2.0%, while the total amount of peaks other than Panipenem must not exceed 6.0%.
Panipenem is moisture-sensitive and hygroscopic. The JP description specifically states that the substance can deliquesce in the presence of moisture. Pharmaceutical-grade Panipenem should therefore be handled in controlled environmental conditions with suitable moisture-protective packaging.
Storage and retest conditions should follow the applicable validated stability data and controlled API specification.
A pharmaceutical Panipenem API Manufacturer may provide quality documentation such as:
Panipenem API is relevant to pharmaceutical manufacturers developing or manufacturing carbapenem-based injectable products. Because the API has a defined pharmacopoeial potency requirement and specific related-substance controls, analytical consistency and moisture control are important aspects of pharmaceutical API manufacturing.
For Panipenem Bulk API, quality documentation should clearly identify the substance as Panipenem, CAS 87726-17-8, rather than confusing it with the Panipenem/Betamipron combination or another carbapenem antibiotic. The official chemical identity is C₁₅H₂₁N₃O₄S with molecular weight 339.41 g/mol.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.10% |
| Heavy Metals | NMT 20 ppm |
| pH (1% Solution) | 4.5–6.5 |
| Individual Impurity | NMT 2.0% |
| Total Impurities | NMT 6.0% |
| Water Content | NMT 8.0% |