Add the following:
Packaging and storage
Preserve in a well-closed container. No storage requirements specified.NF24
Place a drop of a saturated solution of the sample in a micro test tube, and add a drop of ammonium chloride solution (0.5 in 100) and several mg of zinc powder. Cover the mouth of the tube with a disk of filter paper moistened with a solution in hexane containing p-dimethylaminobenzaldehyde (5 in 100) and trichloroacetic acid (20 in 100). Heat with a small flame for about 1 minute: a pink to red-violet stain appears on the paper.
Dissolve about 250 mg, accurately weighed, in 25 mL of carbon dioxide-free water. Add 2 drops of phenolphthalein TS and titrate with 0.1 N sodium hydroxide VS to the production of a permanent pink color. Each mL of 0.1 N sodium hydroxide is equivalent to 5.905 mg of C4H6O4.
: Catherine Sheehan, B.Sc., Scientist
Expert Committee : (EM105) Excipient Monographs 1
USP29NF24 Page 3442
: Volume No. 31(1) Page 95
Phone Number : 1-301-816-8262