Dimethyl sulfoxide

• BPDimethyl Sulfoxide
• Ph. Eur.Dimethyl Sulfoxide
• USP–NFDimethyl Sulfoxide

DMSO; methyl sulfoxide; methylsulfinylmethane; sulfinylbismethane

Sulfinylbismethane · [67-68-5]

UNII YOW8V9698H · PubChem CID 679

C2H6OS · 78.13

Solvent, humectant, Penetration enhancer

Typical concentrations: — · Dosage forms: Semi-solid

A powerful aprotic solvent and skin penetration enhancer used in topical and transdermal preparations; for example a topical diclofenac solution contains about 45% w/w. It is the standard cryoprotectant for freezing cells, typically at about 5–10% v/v, including in cell and gene therapy products, and is used as a solvent in some parenteral and implantable depot products. A 50% solution is used by bladder instillation for interstitial cystitis.

A clear, colourless, hygroscopic liquid or colourless crystals (it solidifies at cool room temperature), odourless or almost odourless. Even after topical use it gives a characteristic garlic-like taste and breath odour.

Melting point

about 18.5 °C

Boiling point

about 189 °C

Density

about 1.10 g/cm³ at 20 °C

Dielectric constant

about 47 at 20 °C

Solubility

miscible with water (with release of heat), ethanol, acetone, ether and chloroform

Very hygroscopic and otherwise stable; it decomposes slightly at its boiling point. Store in an airtight, light-resistant container; it may freeze in cool storage and should be thawed completely and mixed before use.

Can react violently with strong oxidising agents (such as perchlorates and permanganates), acid chlorides and some reactive halogen compounds. It dissolves or swells many plastics and rubbers, so container, tubing and filter materials must be checked.

Produced by oxidation of dimethyl sulfide, obtained as a by-product of wood pulping, with oxygen or nitrogen dioxide, followed by purification by distillation.

Rapidly absorbed through the skin and able to carry dissolved substances with it, so toxic solutes must not be applied in DMSO. Topical use can cause local irritation, erythema, itching and urticaria (it releases histamine), and patients notice a garlic-like breath odour. Infusion of cells cryopreserved in DMSO can cause nausea, flushing and cardiovascular reactions; lens changes have been seen in some animal species.

Wear suitable gloves (for example butyl rubber; DMSO penetrates many glove materials) and eye protection, and avoid skin contact with solutions of other chemicals. Combustible; keep away from heat and strong oxidisers.

ICH Q3C Class 3 residual solvent. Included in the FDA Inactive Ingredient Database (including topical preparations) and used in approved cell therapy products and in medicines licensed in Europe.

Dimethylacetamide; dimethylformamide; N-methylpyrrolidone.

Because DMSO is so hygroscopic, take up of water changes its solvent power and freezing point; keep containers closed and consider the water content when making stock solutions. Mixing with water is exothermic, so add DMSO to water slowly and allow cooling before use with cells or heat-sensitive materials.