Closantel Sodium CAS 61438-64-0 | High Purity Veterinary Antiparasitic API Manufacturer & Bulk Supplier China

Key Selling Points

✓ Salicylanilide Anthelmintic - Mitochondrial Oxidative Phosphorylation Uncoupler

✓ Highly Effective Against Liver Fluke - Fasciola hepatica & F. gigantica (Adults + Late Immatures)

✓ Active Against Benzimidazole-Resistant Haemonchus contortus - 100% Worm Reduction

✓ Also Effective Against Ivermectin-Resistant Nematodes - Resistance-Breaking Spectrum

✓ Plasma Albumin-Bound - Prolonged Activity Against Blood-Feeding Parasites

✓ Broad Trematode + Nematode + Arthropod Larvae Spectrum - Cattle/Sheep/Goats/Camelids

What Is Closantel Sodium Powder?

Closantel Sodium Powder is the sodium salt of closantel, a synthetic salicylanilide anthelmintic chemically related to rafoxanide and oxyclozanide. It is a broad-spectrum antiparasitic agent with high activity against trematodes (liver flukes), haematophagous gastrointestinal nematodes and the larval stages of certain arthropods in cattle, sheep, goats and South American camelids. Closantel is extensively bound to plasma albumin, which concentrates the drug in the bloodstream and directs its activity primarily toward blood-feeding parasites.

In veterinary practice, closantel sodium is a cornerstone treatment for fascioliasis caused by Fasciola hepatica and Fasciola gigantica, with demonstrated efficacy against adult flukes (97–100%) and late immature stages (6- to 8-week-old flukes, 91–95%). It is also highly effective against blood-sucking gastrointestinal nematodes, notably Haemonchus contortus - including benzimidazole-resistant strains, against which closantel at 5.0 mg/kg achieved 100% worm reduction in controlled trials, and ivermectin-resistant isolates. Additional activity covers lungworms (Dictyocaulus), eyeworms (Thelazia), warble fly larvae (Hypoderma), nasal bot larvae (Oestrus ovis), mites, lice and ticks. Closantel is available as injectable solutions, pour-on formulations and oral drenches, often in combination with ivermectin, abamectin or mebendazole for expanded spectrum. Unlike triclabendazole, closantel does not require hepatic metabolic activation. It has a relatively narrow safety margin: overdosage may cause visual disturbances, blindness and neurological signs, and strict adherence to label dosages and withdrawal periods is essential.

How Does Closantel Sodium Powder Work?

Closantel Sodium Powder exerts its anthelmintic effect primarily as an uncoupler of mitochondrial oxidative phosphorylation in parasite cells. As a proton ionophore, it disrupts the proton gradient across the inner mitochondrial membrane, uncoupling electron transport from ATP synthesis. This inhibition of ATP production - the cell's primary energy currency - induces a profound and irreversible change in the parasite's energy metabolism, ultimately leading to parasite death.

Because Closantel Sodium Powder is highly lipophilic and binds extensively to plasma albumin, it circulates at high concentrations in the blood and is selectively taken up by blood-feeding parasites such as Fasciola flukes and Haemonchus nematodes. In addition to oxidative phosphorylation uncoupling, closantel appears to disrupt ion transport mechanisms across parasite membranes and may inhibit chitinase enzymes critical for larval molting in arthropod parasites. Its activity against both adult and late immature liver flukes reflects sustained drug levels in bile and biliary tissues. The resistance-breaking profile of closantel - efficacy against benzimidazole-resistant and ivermectin-resistant Haemonchus contortus - stems from its distinct mechanism of action, which does not overlap with either the β-tubulin binding of benzimidazoles or the glutamate-gated chloride channel activation of macrocyclic lactones. This makes closantel a valuable tool in integrated parasite management programs where resistance to other anthelmintic classes has emerged. In the host, closantel is absorbed unchanged, has limited tissue distribution beyond the bloodstream, and is slowly eliminated, contributing to its prolonged prophylactic activity against reinfection by blood-feeding parasites.

What Are the Applications of Closantel Sodium Powder?

Liver Fluke (Fascioliasis): Treatment and control of Fasciola hepatica and F. gigantica infections in cattle, sheep and goats - effective against adult and late immature (6–8 week) flukes.
Gastrointestinal Nematodes: Treatment of blood-sucking nematodes including Haemonchus contortus (including benzimidazole- and ivermectin-resistant strains), Bunostomum and other haematophagous strongyles.
Lungworms & Eyeworms: Activity against Dictyocaulus viviparus/filaria (lungworms) and Thelazia species (eyeworms) in cattle and sheep.
Arthropod Larvae: Control of warble fly larvae (Hypoderma bovis/lineatum), nasal bot larvae (Oestrus ovis), mites, lice and tick infestations.
Combination Formulations: API for injectable and pour-on products combined with ivermectin, abamectin or mebendazole for broad-spectrum endectocide activity in cattle, sheep, goats and camelids.

What Is the Difference Between Closantel Sodium and Triclabendazole?

Feature	Closantel Sodium	Triclabendazole
CAS	61438-64-0	68786-66-3
Drug Class	Salicylanilide	Benzimidazole (flukicide)
Mechanism	Oxidative phosphorylation uncoupler	β-tubulin binding
Liver Fluke Stages	Adults + late immatures (6-8 wk)	All stages incl. early immatures (1 wk)
Nematode Activity	Yes (blood-sucking)	Minimal
Arthropod Larvae	Yes	No
Hepatic Activation Required	No	Yes (sulfoxide/sulfone metabolites)
Plasma Protein Binding	High (albumin)	Moderate
Resistance	Emerging	Widespread in many regions
Typical Formulation	Injection / pour-on / oral	Oral drench

How Does Closantel Compare With Other Flukicides?

Feature	Closantel	Rafoxanide	Oxyclozanide	Nitroxynil
CAS	61438-64-0	22662-39-1	2277-92-1	1689-89-0
Class	Salicylanilide	Salicylanilide	Salicylanilide	Substituted phenol
Mechanism	Ox phos uncoupler	Ox phos uncoupler	Ox phos uncoupler	Ox phos uncoupler
Adult Fluke	Excellent	Excellent	Good	Excellent
Immature Fluke	Late (6-8 wk)	Late (6-8 wk)	Adults only	Late (6-8 wk)
Nematodes	Blood-sucking	Blood-sucking	Minimal	Blood-sucking
Arthropods	Yes	Yes	No	No
Administration	Injection/pour-on/oral	Oral	Oral	Injection

How Is Closantel Sodium Powder Manufactured?

Closantel Sodium Powder is manufactured through multi-step chemical synthesis involving amide bond formation between a substituted salicylic acid and an aniline derivative, followed by iodination, cyanomethylation and sodium salt formation.

Raw Material QC → 3,5-Diiodo-2-hydroxybenzoic Acid Preparation → Substituted Aniline Synthesis (5-chloro-4-[(4-chlorophenyl)(cyano)methyl]-2-methylaniline) → Amide Coupling → Iodination → Cyanomethylation → Crude Closantel → Sodium Salt Formation → Purification (Recrystallization) → Drying → Milling → Final QC → Packaging

HDM BIO controls key coupling, iodination, cyanomethylation and salt formation parameters to maintain consistent purity and batch quality.

Quality Specifications

Test Item	Standard	Typical Result
Appearance	White to off-white powder	Consistent
Assay (HPLC)	≥98.0%	99.0%
Identity (IR)	Conforms to reference standard	Confirmed
Melting Point	>230°C (decomposition)	>230°C
Loss on Drying	≤0.5%	0.2%
Residue on Ignition	≤0.2%	Compliant
Heavy Metals	≤10 ppm	Compliant
Iodine Content	Within specification	Compliant
Related Substances	Within specification	Pass
Residual Solvents	Within specification	Pass

What Quality Control Tests Are Performed for Closantel Sodium Powder?

Each batch undergoes multi-step quality control before release to verify identity, purity and physical properties.

Raw Material QC → In-Process Control → HPLC Assay → IR Identity Verification → Melting Point Determination → Iodine Content Analysis → Related Substances (HPLC) → Loss on Drying → Heavy Metals → Residue on Ignition → Residual Solvents → Final Batch Release

Key evaluations include identification via infrared (IR) spectroscopy, HPLC active content assay, melting point determination, iodine content analysis, related substances analysis, loss on drying, heavy metal limits, residue on ignition and residual solvent testing. Every commercial batch is supported by a batch-specific COA and relevant analytical documentation for incoming QC and supplier qualification.

What Factors Affect Closantel Sodium Powder Bulk Price?

Closantel Sodium Powder bulk pricing is driven by several key factors:

Synthesis Costs: Multi-step chemical synthesis including amide coupling, iodination and cyanomethylation, with iodine as a costly raw material, directly influences manufacturing expenses.
Purity & Grade: Higher purity (≥99%) and pharmaceutical-grade batches command premiums over standard veterinary grade.
Regulatory Compliance & Certification: GMP-standard API batches with consistent COA and complete export documentation demand a higher price.
Order Volume: Large-scale veterinary pharmaceutical contracts receive steeper per-kilogram discounts than small-batch orders.
Logistics & Geography: Light-protected / cool storage packaging requirements and customs compliance add to the landed cost.

Contact HDM BIO for a current quotation and volume-based pricing.

Why Choose HDM BIO as Your Closantel Sodium Powder Supplier?

High-purity (≥98% / typical 99%) salicylanilide anthelmintic with proven liver fluke and resistant-nematode efficacy
Resistance-breaking profile - active against benzimidazole- and ivermectin-resistant Haemonchus contortus
Broad trematode + nematode + arthropod larvae spectrum for cattle, sheep, goats and camelids
GMP-aligned production, ISO & HACCP certified quality system
Full batch traceability and complete documentation (COA, MSDS, HPLC)
Flexible supply: gram samples to ton-level bulk orders
Global export to 70+ countries with full customs support

Bulk Packaging, Shipping & Storage

Packaging: Foil bags for samples and moisture-proof fiber drums for bulk orders.
Custom Packaging: OEM labeling available.
Shipping Documents: COA, MSDS/SDS, commercial invoice, packing list and customs documentation available according to order requirements.
Storage: Store tightly sealed in a cool, dry, light-protected environment. Shelf life: 24 months.
Handling: For veterinary raw material use only; not for direct clinical administration.

Frequently Asked Questions About Closantel Sodium Powder

Q1: What is Closantel Sodium Powder?

A: The sodium salt of closantel, a synthetic salicylanilide anthelmintic used for liver fluke, blood-sucking nematodes and arthropod larvae in cattle, sheep, goats and camelids.

Q2: What is the CAS number?

A: 61438-64-0.

Q3: How does closantel work?

A: It uncouples mitochondrial oxidative phosphorylation in parasite cells, inhibiting ATP synthesis and disrupting energy metabolism. It also disrupts membrane ion transport and may inhibit chitinase in larval parasites.

Q4: What parasites does closantel treat?

A: Liver flukes (Fasciola hepatica, F. gigantica - adults and late immatures), blood-sucking nematodes (Haemonchus contortus, including resistant strains), lungworms, eyeworms, warble fly larvae, nasal bots, mites, lice and ticks.

Q5: Is closantel effective against resistant worms?

A: Yes. Closantel has demonstrated 100% efficacy against benzimidazole-resistant Haemonchus contortus and remains active against many ivermectin-resistant isolates, due to its distinct mechanism of action.

Q6: What documents are provided with each batch?

A: Batch-specific COA, HPLC report, IR identity records, melting point data, iodine content analysis, MSDS/SDS and relevant export documentation.

Q7: What purity do you supply?

A: Standard ≥98% HPLC; typical batch result 99%. Higher grades available on request.

Q8: Where can I buy it from China?

A: HDM BIO supplies bulk Closantel Sodium Powder with batch COA and global export support.

Q9: How much does Closantel Sodium Powder cost?

A: Bulk pricing depends on synthesis costs (including iodine raw material), purity/grade, regulatory compliance, order volume and logistics. Contact HDM BIO for a current quotation.

Q10: Is closantel safe?

A: Closantel has a relatively narrow safety margin. Overdosage may cause visual disturbances, blindness and neurological signs. Use strictly according to label dosages under veterinary supervision, and observe required withdrawal periods. Not for direct clinical administration.