1,2,3-Propanetricarboxylic acid, 2-hydroxy-.
Citric acid [77-92-9].
Monohydrate 210.14 [5949-29-1].
Packaging and storage— Preserve in tight containers.
Labeling— Label it to indicate whether it is anhydrous or hydrous.
Identification— A solution responds to the tests for Citrate á191ñ.
Readily carbonizable substances—
Transfer 1.0 g, powdered for the
test, to a 22- × 175-mm test tube previously rinsed with 10 mL of sulfuric acid TS and
allowed to drain for 10 minutes. Add 10 mL of sulfuric acid TS, agitate until solution is
complete, and immerse in a water bath at 90 ± 1
for 60 ± 0.5 minutes, keeping the level of the acid below the level of the water during
the entire period. Cool the tube in running water, and transfer the acid to a
color-comparison tube: the color of the acid is not darker than that of a similar volume
of Matching Fluid K (see Color and Achromicity á631ñ
) in a matching tube, the tubes being
observed vertically against a white background.
Sulfate— To 10 mL of a solution (1 in 100) add 1 mL of barium
chloride TS to which has been added 1 drop of hydrochloric acid: no turbidity is produced.
Limit of oxalate— Neutralize 10 mL of a solution (1 in 10) with 6 N
ammonium hydroxide, add 5 drops of 3 N hydrochloric acid, cool, and add 2 mL of calcium
chloride TS: no turbidity is produced.
Organic volatile impurities, Method IV á467ñ:
meets the requirements.
Place about 3 g of Citric Acid in a tared flask, and weigh
accurately. Dissolve in 40 mL of water, add phenolphthalein TS, and titrate with 1 N
sodium hydroxide VS. Each mL of 1 N sodium hydroxide is equivalent to 64.04 mg of C6
: Catherine Sheehan,
Expert Committee : (EMC) Excipients: Monograph Content
USP28–NF23 Page 483
: Volume No. 30(2) Page 677
Phone Number : 1-301-816-8262