Fluralaner: An Isoxazoline-Class Active Ingredient

Fluralaner (CAS 864731-61-3) belongs to the isoxazoline class of active ingredients. This page explains what that class is, where fluralaner sits within it, and what a buyer should know about the material as a raw material for manufacturing.

What is an isoxazoline?

An isoxazoline is an organic compound built on an isoxazoline ring – a five-membered ring containing one oxygen and one nitrogen atom, with one carbon-carbon double bond. In active-ingredient chemistry, the isoxazoline core is decorated with aromatic and halogenated substituents to give molecules with useful biological and physical properties.

Feature	Note
Core	Isoxazoline ring (O + N in a five-membered ring)
Substituents	Aromatic groups; halogen atoms (F, Cl)
Consequence	Lipophilic, often poorly water-soluble molecules

Fluralaner within the class

CAS number	864731-61-3
Molecular formula	C₂₂H₁₇Cl₂F₆N₃O₃
Molecular weight	About 556 g/mol
Grade / form	Non-sterile API / intermediate

Fluralaner is one of the best-known isoxazoline active ingredients. Its high degree of halogenation (six fluorine, two chlorine atoms) makes it lipophilic and poorly water-soluble, which shapes its formulation and its handling.

What the class means for a buyer

Chemistry is similar; products are not – isoxazoline actives share a core but differ in substituents, so their properties, patents and regulatory status differ.
Documents matter – as an active-ingredient raw material, fluralaner is bought on its specification, COA and regulatory documents, not on chemical similarity alone.
Manufacturing, not use – fluralaner is supplied as a raw material for making formulated products; it is not a finished product.

Frequently Asked Questions

What class of chemical is Fluralaner?

It is an isoxazoline – a class defined by the isoxazoline ring, substituted with aromatic and halogenated groups.

What is the formula of Fluralaner?

C₂₂H₁₇Cl₂F₆N₃O₃ (MW about 556 g/mol).

Is Fluralaner a finished product?

No – it is a non-sterile active-ingredient raw material for manufacturing, subject to registration and GMP requirements.

Why is it lipophilic?

Because of its high halogen content (six F, two Cl) and aromatic structure, which reduce water solubility.

Are all isoxazolines the same to buy?

No – they differ in substituents, properties, patents and regulatory status; buy against the specific active ingredient and its documents.