Overview
Fluralaner is a systemic insecticide and acaricide belonging to the isoxazoline chemical class, first approved for veterinary use in 2014. Developed by MSD Animal Health (Merck Animal Health), it revolutionized parasite control with its extended duration of action—providing up to 12 weeks of protection from a single dose. The compound selectively targets invertebrate GABA receptors, causing hyperexcitation and death of ectoparasites while demonstrating low mammalian toxicity. As a veterinary active pharmaceutical ingredient (API), fluralaner is primarily formulated into chewable tablets (e.g., Bravecto) and spot-on solutions. Its unique pharmacokinetic profile allows redistribution through sebaceous glands, maintaining effective concentrations in skin and hair follicles. Regulatory approvals exist in over 80 countries for canine and feline use, with specific indications against Ixodes, Rhipicephalus, and Ctenocephalides species.
Physical and Chemical Properties
Fluralaner appears as a white to off-white crystalline powder with moderate thermal stability, decomposing above 205°C. The compound contains two chlorine atoms and six fluorine atoms in its molecular structure, contributing to its lipophilic nature (logP ~5.3). This property enhances skin penetration and tissue distribution in animals. Spectroscopic characterization shows characteristic IR absorption at 1700 cm−1 (C=O stretch) and 1600 cm−1 (aromatic C=C). The substance demonstrates pH stability between 3-9 but may degrade under strong UV light. Analytical methods typically employ HPLC-UV or LC-MS with reverse-phase C18 columns, achieving detection limits below 0.1 ppm for residue analysis.
Main Applications
Fluralaner's primary application is in companion animal healthcare, with formulations specifically designed for dogs (25-140 mg/kg body weight) and cats (40 mg/kg). It provides broad-spectrum activity against fleas (Ctenocephalides felis), ticks (Ixodes scapularis, Rhipicephalus sanguineus), mites (Sarcoptes scabiei), and lice (Trichodectes canis). Beyond veterinary medicine, research explores its potential in agricultural pest control, particularly against varroa mites in apiculture. However, regulatory approvals for non-veterinary uses remain limited due to environmental persistence concerns. Some countries permit fluralaner-impregnated collars for extended parasite prevention, though oral formulations dominate the market due to better dose control and owner compliance.
Safety and Storage
Pure fluralaner requires careful handling with nitrile gloves, safety goggles, and respiratory protection when processing powdered forms. The LD50 in rats exceeds 2,000 mg/kg orally, but chronic exposure may cause liver enzyme alterations. Environmental precautions are critical—the compound is highly toxic to aquatic invertebrates (EC50 Daphnia magna <0.1 mg/L). Commercial formulations should be stored in original packaging at controlled room temperature (15-30°C), avoiding freezing. Bulk API requires double-sealed containers with desiccants under inert gas (nitrogen) to prevent oxidation. Shelf life typically reaches 36 months when stored properly. Spill management involves absorption with inert material and disposal as hazardous waste per local regulations.
B2B Procurement Guide
When sourcing fluralaner for pharmaceutical production, prioritize suppliers with: 1) WHO-GMP or EU-GMP certification for veterinary APIs, 2) complete DMF (Drug Master File) documentation, and 3) batch-specific COAs with HPLC purity ≥98.5%. Key quality parameters include residual solvents (ICH Q3C limits), heavy metals (<20 ppm), and microbial counts. Lead times for commercial quantities (25+ kg) typically range 8-12 weeks. Consider incoterms carefully—many suppliers prefer CIF shipments due to controlled substance regulations. Sample testing should verify polymorphic form (Form I is the preferred crystalline modification) and particle size distribution (D90 <50μm for tablet formulations). Some manufacturers offer toll processing services for premixes to streamline downstream production.