Description

Colistin Sulfate is a polymyxin antibiotic complex derived from *Bacillus polymyxa* var. *colistinus*, widely recognized for its potent bactericidal activity against Gram-negative pathogens. Its primary commercial value lies in its critical role as a last-resort therapeutic agent in human medicine and as a vital growth promoter and therapeutic in veterinary applications. This product is essential for manufacturers in the pharmaceutical, animal health, and feed additive industries who require a reliable, high-purity active pharmaceutical ingredient (API) to ensure product efficacy and safety.

Application

• Pharmaceutical API: Used in the formulation of injectable and topical medications for treating multidrug-resistant Gram-negative infections in humans, such as those caused by *Pseudomonas aeruginosa*, *Acinetobacter baumannii*, and *Klebsiella pneumoniae*.
• Veterinary Medicine: A key component in oral and injectable preparations for treating enteric and systemic bacterial infections in livestock, poultry, swine, and companion animals.
• Animal Feed Additive: Incorporated at sub-therapeutic levels to promote growth, improve feed efficiency, and prevent bacterial diseases in food-producing animals.
• Research & Development: Serves as a critical reference standard and active compound in microbiological research, antimicrobial susceptibility testing, and the development of new combination therapies.
• Aquaculture: Employed in medicated feeds to control bacterial infections in farmed fish and shrimp, supporting stock health and yield.

Basic Information

Product Name	Colistin Sulfate
CAS No.	1264-72-8
Molecular Formula	C52H98N16O13 • 2H2SO4 (for Colistin A)
Molecular Weight	~1745.9 g/mol (for Colistin A sulfate)
Synonyms	Polymyxin E Sulfate; Colimycin; Coly-Mycin S; Multimycin; Colistin Sulphate; Colistimethate Sodium precursor; CMS precursor; [1-[4-[[(2S)-5-Amino-1-[[(2S,3R)-1-[[(2S)-5-Amino-1-[[(2S)-2-amino-3-hydroxypropanoyl]amino]pentan-2-yl]amino]-3-hydroxy-1-oxobutan-2-yl]amino]-1-oxopentan-2-yl]amino]-3-hydroxybutanoyl]piperidine-4-carbonyl]-L-threonyl-D-leucyl-L-α,γ-diaminobutyryl-L-α,γ-diaminobutyric acid sulfate
EINECS	215-034-5

Quality Control

Our Colistin Sulfate is manufactured under strict quality management systems to ensure batch-to-batch consistency and compliance with major pharmacopoeial standards. Each lot undergoes comprehensive analytical testing, including potency (assay), identification, purity profiling, and specific tests for related substances and residual solvents. A Certificate of Analysis (COA) documenting compliance with specifications for USP, EP, or customer-defined grades is provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). This material is hygroscopic (moisture-sensitive) and must be kept in a low-humidity environment to prevent degradation and clumping. For long-term storage, consider desiccated conditions.

Specification

Item	Specification
Appearance	White or almost white powder
Identification (IR)	Conforms to standard
Identification (HPLC)	Retention time corresponds to reference
pH (1% solution)	4.0 - 6.0
Assay (on dried basis)	≥ 19,000 IU/mg
Loss on Drying	≤ 7.0 %
Sulfated Ash	≤ 1.0 %
Related Substances (HPLC)	Total impurities ≤ 5.0%
Colistin A & B Content (HPLC)	As per customer grade requirement
Heavy Metals	≤ 20 ppm
Bacterial Endotoxins	< 0.067 EU/IU (for injectable grade)
Microbial Enumeration	Conforms to EP/USP

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.