C12H14O4 222.24

1,2-Benzenedicarboxylic acid, diethyl ester.
Diethyl phthalate [84-66-2].

Packaging and storage— Preserve in tight containers.

USP Reference standards 11— USP Diethyl Phthalate RS.

Identification, Infrared Absorption 197F, on undried specimen.

Specific gravity 841: between 1.118 and 1.122, at 20.

Refractive index 831: between 1.500 and 1.505, at 20.

Acidity— Mix 20.0 g with 50 mL of alcohol that previously has been neutralized to a phenolphthalein endpoint, and titrate with 0.10 N sodium hydroxide to a phenolphthalein endpoint: not more than 0.50 mL is required for neutralization.

Water, Method I 921: not more than 0.2%.

Residue on ignition 281— Heat gently about 10 g, accurately weighed, until the liquid has evaporated, and ignite the residue to constant weight. Not more than 0.02% is found.

Residual solvents 467: meets the requirements.

Assay— Transfer about 1.5 g of Diethyl Phthalate, accurately weighed, to a flask, add 50.0 mL of 0.5 N alcoholic potassium hydroxide VS, attach a reflux condenser to the flask, and boil on a water bath for 1 hour. Add 20 mL of water, then add phenolphthalein TS, and titrate the excess potassium hydroxide with 0.5 N hydrochloric acid VS. Perform a blank determination (see Residual Titrations under Titrimetry 541). Each mL of 0.5 N potassium hydroxide is equivalent to 55.56 mg of C12H14O4.

Expert Committee : (EM105) Excipient Monographs 1

USP29–NF24 Page 3326

Phone Number : 1-301-816-8262