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Methylene Blue USP API (122965-43-9)

Methylene Blue USP Chemical Structure

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Methylene Blue or methylthionium chloride is an organic compound that has several medical uses, and is also used as a dye or staining agent. It has been approved for treatment of methemoglobinemia and is also known to treat urinary tract infections.

Macsen Labs is a manufacturer and supplier of Injectable pharma grade Methylene Blue USP API (Methylthioninium Chloride) of high purity grade for injection and other pharmaceutical applications. Along with United States Pharmacopoeia standard, we also supply Ph eur or EP, BP and CP grades of this API.

Macsen Labs group’s Methylene Blue Synthesis Process granted a patent from the Indian patent office

The Indian Patent Office granted a patent to Mr Achal Agrawal, CEO of Macsen Labs, Udaipur. The title of the patent is Novel Improved Method for Synthesis of Diaminophenothiazine Compounds and it concerns a novel process for synthesising the compound Methylthioninium Chloride or Methylene Blue. Macsen Labs has now achieved a unique position by this patent and from now nobody will be able to copy this process. Read more

Macsen Labs is a US FDA, EUGMP – WC, WHO GMP, ISO, Certified Manufacturer of high quality Methylene Blue USP based out of India and has substantial experience in manufacturing this API.

Name of Product Methylene Blue
Pharmacopoeial Name Methylene Blue USP
Synonyms Methylthioninium Chloride ; Basic Blue 9 ; Zinc free Methylene Blue ; C.I 52015 ; Methylene Blue Trihydrate
CAS No 122965-43-9
Molecular Formula C16H18ClN3S


SR. No Criteria Limit/Specification
1 Appearance and Odor Dark Green or Blue crystals or crystalline Powder having a bronze-like luster. Is odorless or practically so, and is stable in air. Its Solution in water and in alcohol are deeqblue in Golor
2 Relative Solubility Slightly Soluble in Water and in Alcohol
A. Infrared (IR) Absorption The IR Spectrum is concordant with the reference spectrum of Methylene Blue.
B. Retention Time (RT) The RT of the major peak of the Sample solution corresponds to that of the Standard Solution. As obtained in the Assay.
C. Identification of Chloride Meets the Requirements
A. Residue on Ignition NMT 0.15%
B. Arsenic PP
C. Copper or Zinc NMT 100 ppm of Zinc and NMT 200 ppm of Copper
5 Organic Impurities
Name Relative RT Acceptance Criteria NMT %
Azure B 0.8 2.5
Unspecified impurity-01 0.48 0.10
Unspecified impurity-02 0.6 0.10
Total Impurities (Excluding Azure- B) ---- 0.5
6 Loss on Drying (LOD) 8.0% to 22.0%
7 Bacterial EndotoxiRS Test NMT 2.5 USP Endotoxin Units/mL
8 Microbial Enumeration Test: Total aerobic microbial count (TAMC) NMT 102 cfu/g
9 ASSAY ( BY HPLC) 97.0% - 103.0% (on dried basis)

Buy the best quality Methylene Blue USP used for topical antiseptic, urinary tract antiseptic, antidote injection for methemoglobinemia & cyanide poisoning from Macsen Laboratories.

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    Resources on Methylene Blue

    Methylene Blue | Chemistry, Uses & Side effects

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    Methylene Blue & Covid-19 – Research So Far

    Staining with Methylene Blue | Different uses and examples

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