Skip to content
Molekula

Molekula

Erythromycin stearate

SKU 32742526 CAS 643-22-1 C37H67NO13·C18H36O2 MW 1018.40 Made to order Bulk quantities on request

Supplying 4,500+ customers in over 80 countries

ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 1999 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need

Erythromycin stearate is the stearic acid salt of erythromycin, a natural macrolide antibiotic produced by fermentation of Saccharopolyspora erythraea, used to treat bacterial infections, particularly in patients allergic to penicillin. It is available as a white to off-white powder with a molecular formula of C37H67NO13·C18H36O2 and a molecular weight of 1018.40 g/mol. It has a CAS number of 643-22-1 and should be stored at 2 to 8 °C. The substance is classified as dangerous.

Molekula supplies Erythromycin stearate at A,B,C >55%, B <12%, C <5% purity in 25 g packs, from £37.08 inc. VAT. It is made or sourced to order. Every batch ships with a certificate of analysis, and safety data sheets are available in 6 languages. Larger quantities, up to multi-tonne, are quoted on request.

Expect a response within hours Speak to a chemist: +44 (0) 3302 000333

Example image for illustration only. Other packaging and pack sizes are available.

Pricing & pack sizes

Pack sizes & pricing

On backorder — expected to ship by 5 December 2026

These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.

Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.

  • 25 g — £30.90 per pack ex VAT · £37.08 inc. VAT

Need a different quantity or pack?

Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.

Quantity
Unit
Needed by
Full name
Email
Company
Phone (optional)
Notes

Expect a response within hours

Prices exclude VAT/sales tax and shipping.

Specifications

Property Value
Appearance White powder
Water ≤4.0%
Identification Conforms to reference
Assay A,B,C >55%, B <12%, C <5%
Ethanol ≤0.5%
Residue on Ignition ≤1.0%

Storage & handling

Property Value
Storage Temperature 2 to 8 °C
Acidity Acid

Literature values

Published physical properties of the substance, not batch specifications.

Property Value
Appearance Crystals
Odour Practically odorless

Source: PubChem CID 12559 (HSDB)

Identification

Property Value
SKU 32742526
CAS Number 643-22-1
IUPAC Name (3R,4S,5S,6R,7R,9R,11R,12R,13S,14R)-6-[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-7,12,13-trihydroxy-4-[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-3,5,7,9,11,13-hexamethyl-oxacyclotetradecane-2,10-dione;octadecanoic acid
EC Number 211-396-1
Molecular Formula C37H67NO13·C18H36O2
Molecular Weight 1018.40
Exact Mass 1017.7328
SMILES CCCCCCCCCCCCCCCCCC(=O)O.CC[C@@H]1[C@@]([C@@H]([C@H](C(=O)[C@@H](C[C@@]([C@@H]([C@H]([C@@H]([C@H](C(=O)O1)C)O[C@H]2C[C@@]([C@H]([C@@H](O2)C)O)(C)OC)C)O[C@H]3[C@@H]([C@H](C[C@H](O3)C)N(C)C)O)(C)O)C)C)O)(C)O
InChIKey YAVZHCFFUATPRK-YZPBMOCRSA-N
InChI InChI=1S/C37H67NO13.C18H36O2/c1-14-25-37(10,45)30(41)20(4)27(39)18(2)16-35(8,44)32(51-34-28(40)24(38(11)12)15-19(3)47-34)21(5)29(22(6)33(43)49-25)50-26-17-36(9,46-13)31(42)23(7)48-26;1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h18-26,28-32,34,40-42,44-45H,14-17H2,1-13H3;2-17H2,1H3,(H,19,20)/t18-,19-,20+,21+,22-,23+,24+,25-,26+,28-,29+,30-,31+,32-,34+,35-,36-,37-;/m1./s1
PubChem CID 12559
REACH Code Y110
HTS Code 29415000
Tariff Code 2941500000

Safety & GHS

Danger
  • GHS pictogram — Health Hazard Health Hazard GHS07
  • GHS pictogram — Serious Health Hazard Serious Health Hazard GHS08

Hazard statements

  • H317 May cause an allergic skin reaction
  • H319 Causes serious eye irritation
  • H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled

Precautionary statements

  • P261 Avoid breathing dust/fume/gas/mist/vapours/spray
  • P264 Wash thoroughly after handling
  • P280 Wear protective gloves/protective clothing/eye protection/face protection
  • P302+352 IF ON SKIN: Wash with soap and water
  • P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing

Documents

Certificate of Analysis (CoA) by batch

Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.

Quality certificates

Molekula Group is certified to ISO 9001:2015 (quality) and ISO 14001:2015 (environmental management), audited by a UKAS-accredited body. Both certificates are valid to 17 May 2028.

Synonyms

  • Abboticine
  • Bristamycin
  • Dowmycin E
  • Eratrex
  • Erypar
  • Erythrocin stearate
  • Ethril
  • Gallimycin
  • Pfizer-E
  • Wyamycin S

Frequently asked questions

What is erythromycin stearate used for?

Erythromycin stearate is an antibiotic used to treat bacterial infections, particularly in patients allergic to penicillin.

What is the chemical formula and molecular weight of erythromycin stearate?

The formula is C37H67NO13·C18H36O2 with a molecular weight of 1018.40 g/mol.

How should erythromycin stearate be stored?

Store at 2 to 8 °C; protect from light and moisture.

What grade of erythromycin stearate does Molekula supply?

Molekula supplies erythromycin stearate for research and development, specified for appearance, water content, identification, assay, ethanol and residue on ignition.

Can Molekula supply erythromycin stearate in bulk?

Yes, Molekula can supply erythromycin stearate in bulk quantities—please contact us for pricing and availability.

What documentation comes with an order of erythromycin stearate?

Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS); additional documentation is available upon request.

Where can I buy Erythromycin stearate?

Directly from Molekula, which lists Erythromycin stearate in 25 g packs from £37.08 inc. VAT, with a certificate of analysis for every batch. Larger quantities are quoted on request. Molekula's offices: United Kingdom, France, Spain, Germany, Italy, United States and China.

Ready to order or need a custom pack?

Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.

Talk to a chemist
Documents Pricing
Request a quote
Tell us the product and the quantity you need — including quantities larger than our listed packs. Expect a response within hours.
Full name
Company
Email
Phone (optional)
Product
Quantity needed

Ask for whatever you actually need — the pack sizes on our catalogue pages are a starting point, not a limit.

Message
View basket