C6H5Na3O7 (anhydrous) 258.07

1,2,3-Propanetricarboxylic acid, 2-hydroxy-, trisodium salt.
Trisodium citrate (anhydrous) [68-04-2].

Trisodium citrate dihydrate 294.10 [6132-04-3].

Packaging and storage— Preserve in tight containers.

Labeling— Label it to indicate whether it is anhydrous or hydrous.

Identification—

Alkalinity— A solution of 1.0 g in 20 mL of water is alkaline to litmus paper, but after the addition of 0.20 mL of 0.10 N sulfuric acid no pink color is produced by 1 drop of phenolphthalein TS.

Water, Method III 921— Dry it at 180 for 18 hours: the anhydrous form loses not more than 1.0%, and the hydrous form between 10.0% and 13.0%, of its weight.

Tartrate— To a solution of 1 g in 2 mL of water add 1 mL of potassium acetate TS and 1 mL of 6 N acetic acid. Rub the wall of the tube with a glass rod: no crystalline precipitate is formed.

Heavy metals 231— Dissolve a portion equivalent to 4.4 g of anhydrous sodium citrate in enough water to make 50 mL of stock solution. Transfer 12 mL of this stock solution to a 50-mL color-comparison tube (Test Preparation). Transfer 11 mL of the stock solution to a second 50-mL color-comparison tube containing 1.0 mL of Standard Lead Solution (Monitor Preparation). Transfer 1.0 mL of Standard Lead Solution and 11 mL of water to a third 50-mL color-comparison tube (Standard Preparation). Proceed as directed for Procedure, omitting the dilution to 50 mL: the limit is 0.001%.

Residual solvents 467: meets the requirements.

Assay— Transfer about 350 mg of Sodium Citrate, previously dried at 180 for 18 hours and accurately weighed, to a 250-mL beaker. Add 100 mL of glacial acetic acid, stir until completely dissolved, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 8.602 mg of C6H5Na3O7.

Expert Committee : (MDCV05) Monograph Development-Cardiovascular

USP29–NF24 Page 1979

Phone Number : 1-301-816-8305