Pipemidic Acid is a synthetic antibacterial active pharmaceutical ingredient belonging to the pyridopyrimidine/quinolone antibacterial class. It has been used in pharmaceutical preparations for the management of bacterial infections, particularly infections involving the urinary, gastrointestinal and biliary tracts. Pipemidic acid acts as an antibacterial agent and is associated with inhibition of bacterial DNA synthesis.
For pharmaceutical applications, Pipemidic Acid is commonly encountered as Pipemidic Acid Trihydrate (Pipemidic Acid Hydrate). The trihydrate has the molecular formula C₁₄H₂₃N₅O₆ and molecular weight 357.36 g/mol. Its CAS Number is 72571-82-5. The corresponding anhydrous pipemidic acid has CAS 51940-44-4 and molecular weight 303.32 g/mol.
Pipemidic Acid Trihydrate is described in the Japanese Pharmacopoeia (JP XVIII) as a pale yellow crystalline powder. It is freely soluble in acetic acid, very slightly soluble in water, practically insoluble in methanol and ethanol, and dissolves in sodium hydroxide solution. The Japanese Pharmacopoeia specifies a melting point of approximately 250°C with decomposition.
The Ph. Eur./BP monograph for Pipemidic Acid Trihydrate identifies the substance as 8-ethyl-5-oxo-2-(piperazin-1-yl)-5,8-dihydropyrido[2,3-d]pyrimidine-6-carboxylic acid trihydrate and specifies a content range of 98.5% to 101.0% on the dried substance.
Pipemidic Acid Hydrate can be evaluated through identity, purity, related substances, water content, residue on ignition and assay testing. JP XVIII specifies chloride NMT 0.021%, sulfate NMT 0.048%, heavy metals NMT 10 ppm, and arsenic NMT 2 ppm. Water is specified at 14.5–16.0%, reflecting the trihydrate form, while residue on ignition is NMT 0.1%.
The JP XVIII assay is performed by potentiometric titration with 0.1 mol/L perchloric acid, with the content calculated as pipemidic acid on the anhydrous basis.
Pipemidic Acid API is used in pharmaceutical manufacturing and analytical applications associated with antibacterial formulations. Its established antibacterial activity includes activity against various Gram-negative bacteria and some Gram-positive bacteria.
The API is suitable for pharmaceutical development and manufacturing where controlled identity, purity, assay, hydration state and batch-to-batch consistency are required.
Pipemidic Acid API manufactured for pharmaceutical applications should be controlled according to the applicable product specification and claimed pharmacopoeial standard. Quality evaluation can include identity testing, assay, related substances, water content, residue on ignition and elemental impurity testing as applicable.
For commercial requirements, customers can request the applicable Certificate of Analysis (CoA), product specification, technical documentation and regulatory/quality documentation for Pipemidic Acid API.
Note: The exact specification should correspond to the physical form supplied. For Pipemidic Acid Trihydrate, the hydrate-specific limits should be used rather than specifications intended for anhydrous Pipemidic Acid.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.5–101.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 10 ppm |
| Water Content | 14.5–16.0% |