Quick Facts
| CAS Number | 73231-34-2 |
|---|---|
| Molecular Formula | C12H14Cl2FNO4S |
| Molecular Weight | 358.21 |
| Pharmacopoeia | CVP, IN HOUSE |
| Packaging | 25 KG/DRUM |
Product Overview
Florfenicol was developed by Schering-Plough Corporation (now part of Merck Animal Health) and launched in the 1990s as Nuflor. Its development was driven by an urgent regulatory problem: chloramphenicol, the most important amphenicol antibiotic against respiratory pathogens, had been banned from food-animal use in the United States (1985) and Europe (1994) due to a rare but fatal idiosyncratic aplastic anemia risk in humans. Thiamphenicol, the immediate chloramphenicol analog, had a better safety profile but was susceptible to the same bacterial acetylation-based resistance mechanism. Florfenicol solved both problems in a single molecule.
The critical structural innovation was replacing the C-3 hydroxyl group of thiamphenicol with a fluorine atom. This single-atom substitution achieved two goals simultaneously: (1) The fluorine atom is not a substrate for bacterial chloramphenicol acetyltransferase (CAT), making florfenicol active against chloramphenicol- and thiamphenicol-resistant strains. (2) The molecule lacks the p-nitro group of chloramphenicol — the moiety responsible for aplastic anemia — resulting in a fundamentally different toxicological profile that allowed regulatory approval for food animals. This elegant structural design made florfenicol the first amphenicol-class antibiotic approved for use in food-producing animals, setting the stage for its widespread adoption across aquaculture, cattle, swine, and poultry sectors.
Florfenicol is now the dominant veterinary antibiotic in global aquaculture, where its broad-spectrum activity against aquatic pathogens (Aeromonas salmonicida, Vibrio anguillarum, Streptococcus iniae, Edwardsiella ictaluri) and stability in medicated feed make it the first-line treatment for bacterial disease outbreaks in finfish and shrimp. In terrestrial livestock, its excellent lung tissue penetration — achieving lung-to-plasma ratios well above 1 — makes it a first-line injectable for bovine respiratory disease (BRD). The aquaculture sector accounts for the largest volume share of global florfenicol consumption, driven by the rapid expansion of intensive aquaculture production in China, Vietnam, India, Indonesia, and Ecuador.
As of mid-2026, the global florfenicol API market continues to grow at approximately 5-7% annually, led by aquaculture demand in Asia-Pacific and Latin America. China is the dominant producer, with API synthesis concentrated in Shandong, Zhejiang, and Hubei provinces. Key quality considerations include enantiomeric purity, particle size distribution for feed-grade products, and stringent residual solvent control. KingWish supplies GMP-certified florfenicol meeting CVP and in-house standards validated against international pharmacopoeia requirements, supporting veterinary pharmaceutical and feed manufacturers worldwide.
Quality Specifications
| Purity (HPLC) | ≥ 98.0%, per CVP/IN HOUSE monograph |
|---|---|
| Related Substances | Thiamphenicol ≤0.5%; any individual impurity ≤0.5%; total ≤2.0% |
| Enantiomeric Purity | Chiral HPLC confirms single enantiomer; meets pharmacopoeia specifications for stereochemical purity |
| Residual Solvents | Methanol ≤ 3,000 ppm; ethyl acetate ≤ 5,000 ppm; per ICH Q3C |
| Heavy Metals | ≤ 20 ppm (aquaculture-grade meets stricter limits per importing country requirements) |
| GMP Status | Manufactured under ICH Q7 GMP conditions |
Veterinary Applications
Aquaculture (Feed Premix)
Florfenicol 10-50% feed premix. Fish: 10 mg/kg BW/day for 10 days for furunculosis, vibriosis, streptococcosis. Shrimp: medicated feed for Vibrio and NHP bacteria. Particle size critical for feed homogeneity.
Injectable (Cattle & Swine)
Florfenicol 300 mg/mL injectable solution. Cattle: 20 mg/kg IM (single dose) or 40 mg/kg SC for BRD. 28-day meat withdrawal. Swine: 15 mg/kg IM every 48h for respiratory disease.
Therapeutic Areas
- Aquaculture: Furunculosis, vibriosis, streptococcosis, columnaris disease, edwardsiellosis
- Cattle: Bovine respiratory disease (BRD), interdigital phlegmon
- Swine: Respiratory disease, atrophic rhinitis, Glasser's disease
- Poultry: Colibacillosis, infectious coryza, pasteurellosis
Sourcing Florfenicol: Key Checks
Documentation
Request CoA with HPLC purity, enantiomeric purity (chiral HPLC), and related substances data. Thiamphenicol content is a key quality indicator — it should be well below 0.5%. For aquaculture, also request particle size distribution data.
Red Flags
Elevated thiamphenicol as an impurity (>0.5%) suggests incomplete fluorination during synthesis. High residual methanol or ethyl acetate indicates poor process control. Prices significantly below market — florfenicol synthesis is multi-step and has a real cost floor.
Packaging & Logistics
Standard: 25 KG/DRUM. Custom packaging and micronized grades available. Store at room temperature (15-30°C), protected from light. Standard lead time 4-8 weeks. Aquaculture-grade may require different packaging specifications.
Market Context
Global florfenicol market grows at 5-7% annually, led by aquaculture expansion in Asia-Pacific and Latin America. China accounts for >80% of API production. Supply has periodically tightened due to environmental enforcement in Chinese chemical provinces. Market report