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Pharmaceutical ingredients

Aspirin vs ibuprofen

Aspirin (C9H8O4, CAS 50-78-2) and ibuprofen (C13H18O2, CAS 15687-27-1) are both listed under analgesics and anti-inflammatories.

Aspirin has a molar mass of 180.16 g/mol, ibuprofen 206.29 g/mol.

Measured melting points are 135 °C for aspirin and 75 to 77 for ibuprofen.

Both carry the GHS signal word Warning.

On CompoundList, 228 suppliers list aspirin and 268 suppliers list ibuprofen.

Data last updated 7 October 2026

Aspirin and ibuprofen compared side by side
Aspirin chemical structure, C9H8O4, CAS 50-78-2
Aspirin
(±)-Ibuprofen chemical structure, C13H18O2, CAS 15687-27-1
Ibuprofen
Identity
Name in our databaseAspirin(±)-Ibuprofen
CAS number50-78-215687-27-1
Molecular formulaC9H8O4C13H18O2
Molar mass180.16 g/mol206.29 g/mol
IUPAC name2-acetyloxybenzoic acid2-[4-(2-methylpropyl)phenyl]propanoic acid
EC number200-064-1239-784-6
Physical properties
AppearanceMonoclinic tablets or needle-like crystalsColorless, crystalline stable solid
Melting point135 °C75 to 77
Boiling point140 °CNot recorded
Density1.4 g/cm³Not recorded
Flash point250 °CNot recorded
Solubility1 g sol in: 300 mL water at 25 °C, 100 mL water at 37 °C, 5 mL alcohol, 17 mL chloroform, 10-15 mL ether, less sol in anhydrous etherIn water, 21 mg/l @ 25 °C
LogP (octanol/water)Computed from the structure1.313.07
Safety (GHS)
Signal wordWarningWarning
Pictograms
GHS07: Harmful or irritant
GHS07: Harmful or irritant
GHS08: Serious health hazard
Hazard statements
  • H302 Harmful if swallowed.
  • H315 Causes skin irritation.
  • H319 Causes serious eye irritation.
  • H335 May cause respiratory irritation.
  • H302 Harmful if swallowed.
  • H319 Causes serious eye irritation.
  • H335 May cause respiratory irritation.
  • H361 Suspected of damaging fertility or the unborn child.
UN numberUN 2811Not recorded
Uses and classification
Uses and functions
  • Analgesics and antipyretics
  • Anti-inflammatories
  • Cardiovascular drugs
  • Analgesic
  • Anti-anaemic agent
  • Anti-arrhythmia drug
  • Analgesics and antipyretics
  • Anti-inflammatories
  • Skin conditioning agents
  • Analgesic
  • Anti-inflammatory agent
  • Anti-ulcer drug
CategoryPharmaceuticals and APIs › Analgesics and anti-inflammatoriesPharmaceuticals and APIs › Analgesics and anti-inflammatories
HS code291822O-Acetylsalicylic acid, its salts and esters291639Aromatic monocarboxylic acids, their anhydrides, halides, peroxides, peroxyacids and…
Market on CompoundList
Suppliers228 suppliers268 suppliers
Supplier countries47 countries, most in China, United States, India48 countries, most in India, United States, China
Price rangeOnly prices set by suppliers who manage their own profilePrice on requestPrice on request

Measured and computed values as shown on each chemical page, plus live listings on CompoundList. Details may have changed, please confirm them with the supplier. Safety data is a summary, not an SDS.

Aspirin
Ibuprofen

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