Methylnaltrexone bromide
Methylnaltrexone bromide (CAS: 73232-52-7, C21H26NO4·Br) is a potent opioid antagonist with a molecular weight of 436.34 g/mol. This quaternary ammonium compound is primarily utilised in research settings as a biochemical tool for studying opioid receptor pharmacology and cellular signalling pathways. Supplied as a white to beige powder and typically shipped on wet ice, it is crucial for researchers investigating the effects and mechanisms of opioid interactions in biological systems.
- IUPAC
- 17-(Cyclopropylmethyl)-4,5α-epoxy-3,14-dihydroxy-17-methyl-6-oxomorphinanium bromide,MNTX,Methylnaltrexonium,Mrz-2663,N-Methylnaltrexone,Naltrexone MB,Quaternary ammonium naltrexone
- Synonyms
- 17-(Cyclopropylmethyl)-4,5α-epoxy-3,14-dihydroxy-17-methyl-6-oxomorphinanium bromideMNTXMethylnaltrexoniumMrz-2663N-MethylnaltrexoneNaltrexone MBQuaternary ammonium naltrexone

Opioid Receptor Research
Methylnaltrexone bromide serves as a valuable research tool for investigating the complex interactions within the opioid system. Its antagonistic properties are essential for discerning receptor-specific effects in various biological assays.
Cellular Signalling Studies
This compound is employed in cell biology research to explore cellular responses mediated by GPCRs, particularly in the context of opioid receptor signalling pathways. It helps researchers understand downstream signalling cascades.
Neuroscience Investigations
Within neuroscience, methylnaltrexone bromide is used to study the role of opioid receptors in neuronal function and signalling. Its use aids in characterising the physiological and pharmacological responses of the nervous system.
| Molecular weight | 436.34 |
|---|---|
| Empirical formula | C21H26NO4 · Br |
| Assay | ≥97% (HPLC) |
| Form | powder |
| Colour | white to beige |
| Solubility | H2O: ≥5 mg/mL |
| Storage temperature | −20°C |


Hazard statements
- H301Toxic if swallowed
- H400Very toxic to aquatic life
Precautionary statements
- P273Avoid release to the environment
- P301IF SWALLOWED
| Transport (UN / ADR) | UN 2811 6.1 / PGIII |
|---|---|
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | T,N |
| Risk statements (R) | 25-50 |
| Safety statements (S) | 45-61 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
| Shipped In | wet ice |
|---|---|
| Storage Condition | desiccated |
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is Methylnaltrexone bromide used for?
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Methylnaltrexone bromide is primarily used in research for studying opioid receptor pharmacology, cellular signalling pathways, and neuroscience investigations. It acts as a potent opioid antagonist.
What are the CAS number and formula for Methylnaltrexone bromide?
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The CAS number for Methylnaltrexone bromide is 73232-52-7, and its empirical formula is C21H26NO4·Br.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies Methylnaltrexone bromide with an assay of ≥97% (HPLC). This product is intended for research purposes and is not supplied as USP, BP, or EP grade.
How should Methylnaltrexone bromide be handled and stored?
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Methylnaltrexone bromide is acutely toxic if swallowed and very toxic to aquatic life. Handle with appropriate personal protective equipment in a well-ventilated area. Store desiccated at -20°C, and note that it is shipped in wet ice.
How is Methylnaltrexone bromide packed and shipped?
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Methylnaltrexone bromide is typically supplied as a white to beige powder. It is shipped under wet ice conditions to maintain stability.
How can I request a quote or sample for Methylnaltrexone bromide?
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To request a quote or sample of Methylnaltrexone bromide, please contact the Tech Serve Solutions sales team through our website or by phone.
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