C10H14N4O4 254.24

1H-Purine-2,6-dione, 7-(2,3-dihydroxypropyl)-3,7-dihydro-1,3-dimethyl-, (±)-.
(±)-7-(2,3-Dihydroxypropyl)theophylline [479-18-5].

Packaging and storage— Preserve in tight containers.

USP Reference standards 11— USP Dyphylline RS.

Identification—

Melting range 741: between 160 and 164.

pH 791: between 5.0 and 7.5, in a solution (1 in 100).

Loss on drying 731— Dry about 1 g, accurately weighed, at 105 for 3 hours: it loses not more than 0.5% of its weight.

Residue on ignition 281: not more than 0.15%.

Chloride 221: A 1.0-g portion shows no more chloride than corresponds to 0.50 mL of 0.020 N hydrochloric acid (0.035%).

Sulfate 221: A 1.0-g portion shows no more sulfate than corresponds to 0.10 mL of 0.020 N sulfuric acid (0.010%).

Heavy metals, Method I 231: 0.002%.

Limit of theophylline— Dissolve 2.0 g in 10 mL of hot water. Cool, add 10 drops of bromothymol blue TS and 5.0 mL of silver nitrate TS, and mix. Not more than 0.50 mL of 0.10 N sodium hydroxide is required to change the color of the solution to blue (0.5%).

Related compounds— Dissolve about 200 mg in a mixture of 30 volumes of methanol and 20 volumes of water in a 10-mL volumetric flask, dilute with the same mixture to volume, and mix (Test solution). Dilute 1 mL of the Test solution with methanol to 100 mL (Diluted test solution). Separately apply 10 µL of each solution to a suitable thin-layer chromatographic plate (see Chromatography 621) coated with a 0.25-mm layer of binder-free chromatographic silica gel mixture. Develop the plate in a suitable chamber containing a mixture of chloroform, dehydrated alcohol, and ammonium hydroxide (90:10:1) until the solvent front has moved about 15 cm. Remove the plate, air-dry at room temperature, and examine under short-wavelength UV light: no spot in the chromatogram of the Test solution other than the principal spot is larger or more intense than the principal spot from the Diluted test solution (1.0%).

Organic volatile impurities, Method I 467: meets the requirements.

Residual solvents 467: meets the requirements.

Assay— Dissolve about 200 mg of Dyphylline, accurately weighed, in 2 mL of formic acid, and carefully add, with stirring, 50 mL of acetic anhydride. Add 0.2 mL of Sudan IV TS, and titrate with 0.1 N perchloric acid VS to a deep violet endpoint. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 25.42 mg of C10H14N4O4.

Expert Committee : (MDPS05) Monograph Development-Pulmonary and Steroids

USP29–NF24 Page 774

Phone Number : 1-301-816-8143