Ractopamine is a synthetic phenethanolamine β-adrenergic receptor agonist used primarily as a veterinary drug and feed additive in livestock production. The commercially recognized pharmaceutical form is Ractopamine Hydrochloride, CAS No. 90274-24-1.
Ractopamine hydrochloride is used in approved veterinary applications to improve feed efficiency, weight gain and carcass leanness in certain food-producing animals. It acts by stimulating β-adrenergic receptors and altering nutrient partitioning toward lean tissue deposition.
Ractopamine is not primarily a human therapeutic API. Its manufacture, handling and use are subject to veterinary-drug, animal-feed and food-residue regulations that differ between countries.
Ractopamine hydrochloride is the hydrochloride salt of ractopamine and belongs to the phenethanolamine class of β-adrenergic agonists.
| Chemical Property | Ractopamine Hydrochloride |
|---|---|
| API Name | Ractopamine Hydrochloride |
| CAS Number | 90274-24-1 |
| Molecular Formula | C18H24ClNO3 |
| Molecular Weight | 337.84 g/mol |
| PubChem CID | 14010333 |
| UNII | 309G9J93TP |
| Chemical Class | Phenethanolamine |
| Pharmacological Class | β-Adrenergic receptor agonist |
| Functional Class | Veterinary drug / growth promoter |
| Physical Form | Solid |
| Stereochemistry | Four stereoisomeric forms in commercial material |
PubChem identifies CAS 90274-24-1 as ractopamine hydrochloride and reports a molecular formula of C18H24ClNO3 and molecular weight of 337.8 g/mol.
Ractopamine belongs to the β-adrenergic receptor agonist class and is classified by JECFA as a veterinary drug and growth promoter.
It is a phenethanolamine-type compound that interacts with β-adrenergic receptors involved in metabolic regulation. The compound has activity at both β1- and β2-adrenoceptors, with stereoisomer-dependent differences in receptor affinity and signaling.
Ractopamine produces its biological effects through stimulation of β-adrenergic receptors. Receptor activation initiates intracellular signaling that can influence lipid metabolism, protein deposition and energy utilization.
In livestock, these effects can promote nutrient partitioning toward lean tissue deposition while reducing the relative accumulation of adipose tissue. This pharmacological activity is associated with improvements in feed efficiency, weight gain and carcass leanness in approved production settings.
Ractopamine is stereoselective in its receptor activity. JECFA identified the RR stereoisomer (butopamine) as the most biologically active stereoisomer, with activity at both β1- and β2-adrenoceptors and more efficient signaling through β2-adrenoceptors.
Ractopamine Hydrochloride is primarily associated with veterinary pharmaceutical and animal-feed applications.
Its evaluated applications include:
JECFA evaluated ractopamine hydrochloride for use in finishing pigs at 5–20 mg/kg feed for feed efficiency and weight gain and 10–20 mg/kg feed for carcass leanness. For finishing cattle, the evaluated range was 10–30 mg/kg feed. These values represent the JECFA evaluation and should not be interpreted as a universal current dosage or authorization for every market.
Ractopamine Hydrochloride is a solid phenethanolamine salt with measurable water solubility and characteristic ultraviolet absorption.
The FDA environmental assessment reports a melting point of 163.9–164.6°C and water solubility of 51.9 g/L at pH 5, 31.0 g/L at pH 7 and 41.2 g/L at pH 9. It also reports UV absorption maxima at 225.8 and 277.6 nm in methanol.
Ractopamine Hydrochloride requires appropriate analytical controls for identification, assay, related substances and stereoisomeric composition.
Common analytical techniques include:
High-performance liquid chromatography can be used for quantitative determination of ractopamine and evaluation of related substances.
Liquid chromatography coupled with tandem mass spectrometry is particularly useful for highly sensitive determination of ractopamine and its residues in biological matrices and food products.
Infrared spectroscopy can be used as an identity test by comparing the characteristic absorption pattern of the API against an authenticated reference standard.
Ractopamine hydrochloride exhibits characteristic UV absorption maxima around 225.8 nm and 277.6 nm, providing useful analytical information for spectroscopic and chromatographic methods.
Chromatographic impurity profiling is important because manufacturing can generate process-related substances and ractopamine-related dimers.
Quality control of Ractopamine Hydrochloride should include appropriate testing for:
FDA regulatory documentation has identified process-related substances associated with ractopamine hydrochloride manufacture, including 4-(p-hydroxyphenyl)butan-2-ol, 4-(p-hydroxyphenyl)butan-2-one, bis-phenolic aza compounds and ractopamine-related dimers.
Because a single universal current public API specification was not verified for every quality parameter, numerical release limits for impurities, water and residue should be based on the applicable approved API specification and validated analytical methods rather than represented as universal pharmacopoeial limits.
Ractopamine contains two chiral carbon atoms, giving rise to four possible stereoisomers:
Commercial Ractopamine Hydrochloride contains these four stereoisomers. JECFA describes the commercial preparation as a racemic mixture of RR, RS, SR and SS stereoisomers.
The RR stereoisomer, commonly referred to as butopamine, has been identified as the most biologically active stereoisomer and demonstrates significant activity at β-adrenergic receptors.
Therefore, stereoisomeric composition is an important consideration when establishing the identity, quality and consistency of Ractopamine Hydrochloride.
Ractopamine Hydrochloride should be handled under controlled conditions appropriate for a veterinary pharmaceutical API.
Recommended handling practices include:
Storage conditions should ultimately be established from validated stability data and the manufacturer's approved specification rather than applying a generic temperature requirement.
A comprehensive Ractopamine Hydrochloride API documentation package can include:
Manufacturing Ractopamine Hydrochloride requires controlled chemical processing followed by purification, hydrochloride salt formation, drying and comprehensive quality testing.
Important manufacturing controls include:
A robust manufacturing process is particularly important for maintaining consistent stereoisomeric composition and controlling process-related impurities.
Ractopamine is a veterinary drug with country-specific regulatory requirements. Its use in food-producing animals is not permitted in all jurisdictions.
JECFA's latest evaluation established an acceptable daily intake of 0–0.001 mg/kg body weight and recommended maximum residue limits expressed as ractopamine of 0.01 mg/kg for muscle and fat, 0.04 mg/kg for liver, and 0.09 mg/kg for kidney in cattle and pigs.
These residue limits are food-safety limits and not API manufacturing specifications. Applicable national regulations should always be checked before commercial use, registration or distribution.
Ractopamine Hydrochloride is a specialized veterinary API used in authorized livestock-production applications. Its quality depends on accurate chemical identification, controlled stereoisomeric composition, effective impurity control and reliable analytical characterization.
A professionally manufactured Ractopamine API should be supported by comprehensive quality documentation, validated analytical testing, controlled manufacturing processes and appropriate stability and storage controls.
Ractopamine Hydrochloride — CAS No. 90274-24-1 — Molecular Weight 337.84 g/mol is the appropriate pharmaceutical/veterinary API form for this product page.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 20 ppm |
| Total Impurities | NMT 0.5% |
| Melting Point | 165–170°C (decomp.) |