Pralidoxime Chloride is a pharmaceutical active ingredient classified as an oxime cholinesterase reactivator and is primarily associated with the management of poisoning caused by organophosphorus compounds. It is commonly known as 2-PAM chloride and is used in pharmaceutical preparations intended for emergency antidotal treatment. Pralidoxime works by helping reactivate acetylcholinesterase that has been inhibited by organophosphate compounds.
Pralidoxime Chloride has the molecular formula C₇H₉ClN₂O and a molecular weight of 172.61 g/mol. The USP monograph identifies Pralidoxime Chloride as pyridinium, 2-[(hydroxyimino)methyl]-1-methyl-, chloride and specifies an assay range of 97.0% to 102.0% on the dried basis.
The material is described as a white to pale-yellow crystalline powder. It is freely soluble in water, making it suitable for pharmaceutical processing into aqueous formulations. Historical USP description information also characterizes Pralidoxime Chloride as a crystalline powder that is freely soluble in water.
Pralidoxime Chloride is an important antidotal API for pharmaceutical formulations used in the treatment of organophosphate poisoning. Organophosphates inhibit acetylcholinesterase, leading to excessive cholinergic activity. Pralidoxime acts as a cholinesterase reactivator by facilitating removal of the organophosphate group from inhibited acetylcholinesterase when administered appropriately.
For pharmaceutical manufacturing, identity and purity control are particularly important because the USP monograph differentiates the desired pralidoxime material from the pralidoxime anti-isomer and pyridine-2-aldoxime. Current USP analytical procedures use liquid chromatography with UV detection at 270 nm for assay and related-substance evaluation.
Pralidoxime Chloride is a pyridinium salt containing the active pralidoxime cation and chloride counterion. Its CAS identification requires attention to isomer designation. USP lists 14018-50-9 for the specified E-isomer and 51-15-0 for the unspecified isomer. This distinction should be maintained in technical documentation and commercial API records.
The USP assay requirement is 97.0–102.0% calculated on the dried basis. The current USP monograph also specifies a Loss on Drying limit of NMT 2.0%, determined by drying at 105°C for 3 hours.
Pralidoxime Chloride API is primarily used in the manufacture of pharmaceutical antidote preparations intended for organophosphate poisoning. It is particularly relevant to emergency medicine where rapid cholinesterase reactivation may be required.
Pralidoxime Chloride is also used in the manufacture of injectable pharmaceutical products. USP maintains a separate Pralidoxime Chloride for Injection monograph, with the finished dosage form subject to additional requirements such as pH, sterility, bacterial endotoxins, and dosage-form quality testing.
Quality control of Pralidoxime Chloride includes identity, assay, related substances, moisture and inorganic residue testing. Current USP identification includes infrared spectroscopy, chloride identification and chromatographic retention-time comparison.
Current USP related-substance criteria include pyridine-2-aldoxime NMT 0.5%, pralidoxime anti-isomer NMT 2.0%, any other individual impurity NMT 0.10%, and total impurities NMT 3.0%. The reporting level for impurities is 0.05%.
For material intended for pharmaceutical parenteral manufacture, additional controls may include bacterial endotoxins and sterility depending on the intended processing and labeling. The USP requirement for material intended for parenteral preparation without an appropriate endotoxin-removal process is NMT 0.10 USP Endotoxin Units/mg.
As a pharmaceutical API manufacturer in India, consistent control of Pralidoxime Chloride quality is important for pharmaceutical companies developing or manufacturing antidotal formulations. Manufacturing controls should cover raw-material qualification, process controls, crystallization, drying, analytical testing and controlled packaging.
The API can be evaluated against applicable USP requirements, including assay, identification, related substances and moisture. Batch documentation can include Certificate of Analysis, analytical test reports, specification sheets and relevant quality documentation according to customer requirements.
Pralidoxime Chloride should be manufactured and handled under appropriate pharmaceutical quality systems, with analytical methods validated or qualified according to the intended regulatory application.
Pralidoxime Chloride should be protected from moisture and stored in well-closed pharmaceutical containers. The Indian Pharmacopoeia draft amendment specifies storage protected from moisture, while the USP monograph specifies preservation in well-closed containers.
Typical documentation available for pharmaceutical API evaluation may include:
Pralidoxime Chloride is an established pharmaceutical antidotal API with recognized USP standards for identity, assay, moisture and related substances. Its defined pharmaceutical quality parameters make analytical control essential for manufacturers of organophosphate poisoning antidote preparations. The combination of pharmacopoeial testing, controlled manufacturing and batch-specific quality documentation supports consistent API quality for pharmaceutical development and production.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 97.0–102.0% |
| Loss on Drying | 2.0% |
| Residue on Ignition | NMT 0.5% |
| Heavy Metals | NMT 20 ppm |
| Individual Impurity | NMT 0.10% |
| Total Impurities | NMT 3.0% |