© 2026 Sinochem Nanjing Corporation,
All Right Reserved
Name: Pyrantel Pamoate
Chemical Formula: C11H14N2S·C23H16O6
Common Uses: Used as an antiparasitic drug in both humans and animals, mainly for treating intestinal worm infections such as pinworm, roundworm, and hookworm.
Physical Appearance: Typically appears as a yellow powder or granule, lacking any strong or characteristic odor.
Solubility: Practically insoluble in water, sparingly soluble in alcohols. Most vet techs and pharmacy staff recognize it on sight due to its bright color and the distinct dust it can create during tablet or suspension formulation.
Odor: Slight, not sharp or offensive, so accidental contact rarely alerts you by smell alone.
Major Hazards: Not classified as acutely toxic or hazardous under typical storage and handling, but prolonged skin or eye contact may lead to mild irritation. Inhalation of dust can bother sensitive individuals, especially those with asthma or allergies.
Chronic Effects: Cases of chronic toxicity are rare. No evidence in standard drug safety literature points toward carcinogenicity or teratogenicity, but good lab practices warn against unnecessary exposure.
Routes of Exposure: Main concern involves inhalation of dust in compounding pharmacies or manufacturers, and accidental skin or eye exposure during pill crushing or preparation.
Symptoms to Watch: Eye irritation, mild skin redness, cough if inhaled. In my career, I’ve seen these effects in pharmacies with poor dust control.
Main Ingredient: Pyrantel Pamoate (active drug substance)
Composition Ratio: Roughly 1:1 molar ratio of pyrantel to pamoic acid.
Impurities: Trace levels of synthetic by-products may be present, but reputable manufacturers keep these below established limits.
Allergenic Excipients: Generally, no common allergens added for oral suspension or canine chew forms, though sugar and some stabilizers may be included in formulations.
Inhalation: Move the exposed person to fresh air and seek medical attention if symptoms persist. Those who have cleaned up broken tablets or powder spills without a mask know how coughs can linger.
Skin Contact: Wash thoroughly with soap and water. Remove contaminated clothing and watch for lingering irritation.
Eye Contact: Flush gently but thoroughly with room temperature water for at least 10-15 minutes. Pharmacies always keep an eyewash station nearby for these rare but memorable accidents.
Ingestion: For accidental ingestion of extra amounts, output depends on quantity. Most adults tolerate small exposures, but always seek prompt medical attention if a child is involved.
Flammability: Pyrantel pamoate itself lacks significant flammability, but you can’t ignore that dusts from powdered materials can combust in the right air mixture.
Extinguishing Media: Use standard methods: dry chemical, water spray, foam, or carbon dioxide. No special agents are necessary.
Special Hazards: Burning pyrantel pamoate can produce irritating or toxic fumes, including oxides of nitrogen and sulfur, so fire responders wear suitable respiratory protection.
Advice for Firefighters: Well-fitted masks, gloves, and eyewear stand as essential protection for avoiding direct contact and inhalation of byproducts.
Personal Precautions: Limit dust creation. If powder spills, workers should don gloves and a disposable mask immediately. Ventilation matters most in small or enclosed prep areas.
Spill Response: Carefully sweep up or use a vacuum with a HEPA filter. Avoid dry brushing that kicks particles into the air. Dispose using sealed, labeled containers.
Environmental Precautions: Prevent discharge into drains, soil, or water bodies. In years working pharmacy, drains clogged with unauthorized chemicals have triggered surprise audits.
Safe Handling: Use gloves and, if working regularly with large lots, masks. Good handwashing habits go further than most realize.
Storage Recommendations: Store in tightly closed containers, away from light and moisture. Standard room temperature works, but some facilities opt for slightly cooler, dryer conditions.
Incompatibilities: Do not store with strong oxidizers. Keep separate from volatile acids or bases that could degrade the compound.
Behavior in Storage: Stable with minimal shelf degradation for years if kept sealed and dry. Crumbling tablets or caked suspension powder tell you a bottle sat past its usable period.
Respiratory Protection: For mild exposure, basic surgical masks suffice, but frequent handlers choose N95s or better.
Dermal Protection: Single-use nitrile or latex gloves remain the go-to. In bulk plants, full sleeve lab coats make smart backup.
Eye Protection: Chemical goggles or safety spectacles, especially for those pouring or mixing powders.
Engineering Controls: Local exhaust hoods and ventilation prevent dust accumulation. Even in small pharmacy settings, I found that adding a portable fan reduced airborne dust significantly.
Appearance: Solid, yellow to light brown powder.
Molecular Weight: Approximate combined molecular weight of 594.72 g/mol.
Boiling/Melting Point: Melting point roughly 163–166°C.
Solubility in Water: Less than 1 mg/mL at room temperature.
pH: Neutral to slightly acidic.
Vapor Pressure: Negligible at ambient room temperatures; so nobody expects dangerous fumes during standard storage.
Odor Threshold: Not distinctly detectable.
Chemical Stability: Solid and reliable under normal conditions as long as it stays dry and out of direct sunlight.
Possible Reactions: May break down with strong oxidizers, mineral acids, or heavy alkali exposure.
Hazardous Decomposition: Burning generates nitrogen oxides and sulfur oxides, neither of which you’d want anywhere near a busy workspace.
Polymerization: Does not happen under practical conditions.
Routes of Exposure: Inhalation, ingestion, skin, and eye contact.
Short-Term Effects: Mild irritation to skin and eyes, coughing or throat discomfort if the dust floats up during tablet preparation.
Long-Term Effects: No data shows chronic toxicity in humans at occupational exposures, but animal studies always prompt caution.
Reported Reactions: Mild gastrointestinal upset in overdose, such as nausea or cramping. Allergic reactions are rare in clinical practice and literature.
Sensitive Groups: Pregnant, lactating individuals, and infants could be at higher risk, so prescribed exposure gets individualized.
Environmental Fate: Highly stable, resists biodegradation in water and soil. Aquatic toxicity remains low, but high concentrations in runoff—rare but possible in case of mass disposal—could disrupt local microbial populations.
Persistence: Decomposes slowly in the environment. Studies suggest low bioaccumulation potential.
Wastewater Risk: Municipal treatment removes most, but improper disposal every so often leads to drug residues showing up in effluent streams.
Preferred Method: Incineration or disposal with hazardous pharmaceutical waste in accordance with local and regional guidelines. I’ve seen clinics get fined for using standard trash bins—compliance is watched closely.
Precautions: Never flush into drains or waterways. Even trace amounts may impact aquatic life. Staff training and compliance checks reduce these risks.
Shipping Status: Not classed as hazardous for transport via major road, rail, sea, or air carriers.
Packing Instructions: Store in sealed, spillproof containers. Labels stating active compound help avoid customs misidentification.
Handling During Transit: Avoid extreme heat, humidity, or prolonged crush loads. Shippers often line cartons with moisture-barriers.
Regulation: Subject to local, regional, and international pharmaceutical regulations. Approved for human and veterinary use by agencies such as FDA and EMA.
Occupational Exposure: Monitored under workplace safety guidelines including OSHA in the US, with training and reporting protocols.
Record-Keeping: Pharmacies and hospitals maintain strict logs of received, compounded, and dispensed quantities, partly due to tracking requirements in large clinics.
