Dibutyl phthalate

• BPDibutyl Phthalate
• Ph. Eur.Dibutyl Phthalate
• USP–NFDibutyl Phthalate

benzene-1,2-dicarboxylic acid dibutyl ester; butyl phthalate; DBP; dibutyl benzene-1,2-dicarboxylate; n-butyl phthalate; phthalic acid dibutyl ester

Dibutyl benzene-1,2-dicarboxylate · [84-74-2]

UNII 2286E5R2KE · PubChem CID 3026

C16H22O4 · 278.34

Plasticiser

Typical concentrations: — · Dosage forms: Solid

Used as a plasticiser in film coatings, including enteric coatings of cellulose acetate phthalate and coatings of ethylcellulose and other polymers, typically at about 10–30% of the polymer weight. It has also been used as a solvent and in insect repellents. Because of its reproductive toxicity its use in medicines is now discouraged.

A clear, colourless or very slightly yellowish, oily liquid that is odourless or almost so.

Boiling point

about 340 °C

Relative density

about 1.043–1.048

Refractive index

about 1.490–1.495

Solubility

very slightly soluble in water; miscible with ethanol, ether, acetone and most organic solvents and oils

Stable. Store in a well-closed container in a cool, dry place.

Incompatible with strong oxidising agents. It softens or dissolves some plastics and rubbers.

Made by esterifying phthalic anhydride with n-butanol in the presence of an acid catalyst, followed by purification.

Of low acute toxicity, but classified in the EU as toxic to reproduction and recognised as an endocrine disruptor; animal studies show effects on male reproductive development. The FDA has recommended (2012) that dibutyl phthalate not be used as an excipient, and the EMA has set a low permitted daily exposure, so exposure from medicines should be minimised. It can irritate the eyes and mucous membranes.

Wear gloves and eye protection and handle in a well-ventilated area; avoid exposure of women of child-bearing potential.

Included in the FDA Inactive Ingredient Database (oral delayed-release capsules and tablets), but FDA guidance (2012) recommends avoiding it as an excipient. EMA guidance on phthalates in medicines (2014) requires justification and labelling, and it is a substance of very high concern under EU REACH.

Diethyl phthalate; dimethyl phthalate; dibutyl sebacate; triethyl citrate; acetyltributyl citrate.

In new products, replace dibutyl phthalate with non-phthalate plasticisers such as triethyl citrate, acetyltributyl citrate or dibutyl sebacate; note that enteric polymers such as cellulose acetate phthalate are not affected by these restrictions, which concern the low-molecular-weight phthalate esters.