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C4H11NO3 121.14

1,3-Propanediol, 2-amino-2-(hydroxymethyl)-.
2-Amino-2-(hydroxymethyl)-1,3-propanediol [77-86-1].
» Tromethamine contains not less than 99.0 percent and not more than 101.0 percent of C4H11NO3, calculated on the dried basis.
Packaging and storage— Preserve in tight containers.
B: To 4.5 mL of a saturated solution of salicylaldehyde add 0.5 mL of glacial acetic acid, and mix. Add 4.0 mL of a solution of Tromethamine (1 in 5), and mix: a yellow color is produced.
C: To 0.5 mL of a 4 in 10 solution of ceric ammonium nitrate in 2 N nitric acid add 3 mL of water and 0.5 mL of a solution of Tromethamine (1 in 5), and mix: the color changes from light yellow to orange.
Melting range 741: between 168 and 172.
pH 791: between 10.0 and 11.5, in a solution (1 in 20).
Loss on drying 731 Dry it at 105 for 3 hours: it loses not more than 1.0% of its weight.
Residue on ignition 281: not more than 0.1%.
Heavy metals, Method II 231: 0.001%.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay— Dissolve about 250 mg of Tromethamine, accurately weighed, in 100 mL of water, add bromocresol purple TS, and titrate with 0.1 N hydrochloric acid VS to a yellow endpoint. Each mL of 0.1 N hydrochloric acid is equivalent to 12.11 mg of C4H11NO3.
Auxiliary Information— Staff Liaison : Feiwen Mao, M.S., Senior Scientific Associate
Expert Committee : (MDOOD05) Monograph Development-Ophthalmics Oncologics and Dermatologicals
USP29–NF24 Page 2222
Phone Number : 1-301-816-8320