Chromatographic purity
The sum of the intensities of all secondary spots obtained from the
Test preparation in
Part I and
Part II corresponds to not more than 2.0%.
Part I
Spray reagent
Dissolve 300 mg of ninhydrin in a mixture of 100 mL of butyl alcohol and 3 mL of glacial acetic acid.
Standard preparation A
[NOTEUse low-actinic glassware.
] Dissolve an accurately weighed quantity of
USP Trientine Hydrochloride RS in methanol to obtain a solution containing 10 mg per mL.
Standard preparation B
[NOTEUse low-actinic glassware.] Dissolve an accurately weighed quantity of diethylenetriamine in methanol to obtain a solution containing 1.0 mg per mL. Transfer 3.0 mL of this solution to a 100-mL volumetric flask, dilute with methanol to volume, and mix.
Standard preparation C
[NOTEUse low-actinic glassware.] Dissolve an accurately weighed quantity of 1-(2-aminoethyl)piperazine in methanol to obtain a solution containing 1.0 mg per mL. Transfer 10.0 mL of this solution to a 100-mL volumetric flask, dilute with methanol to volume, and mix.
Standard preparation D
[NOTEUse low-actinic glassware.] Transfer 5.0 mL of Standard preparation C to a 10-mL volumetric flask, dilute with methanol to volume, and mix.
Test preparation
[NOTEUse low-actinic glassware.] Dissolve an accurately weighed quantity of Trientine Hydrochloride in methanol to obtain a solution containing 10 mg per mL.
Procedure
Apply separately 3 µL each of the
Test preparation, of
Standard preparation B, and of
Standard preparation C to a suitable unwashed, high performance thin-layer chromatographic plate (see
Chromatography 621) having a 1.5-cm preadsorbent zone and coated with a 0.15-mm layer of chromatographic silica gel mixture. To a fourth spot, apply 3 µL each of
Standard preparations A,
B, and
C. To a fifth spot, apply 3 µL each of
Standard preparations A,
B, and
D. Allow the spots to dry, place the plate in a chromatographic chamber, and develop the chromatograms in a solvent system consisting of a mixture of isopropyl alcohol and ammonium hydroxide (3:2) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the developing chamber, mark the solvent front, and dry the plate with the aid of a current of air. Spray the plate with
Spray reagent, dry at 105
for 5 minutes, and observe the plate under long-wavelength UV light. Determine the locus of the diethylenetriamine and the 1-(2-aminoethyl)piperazine spots from the chromatograms of
Standard preparations B and
C, respectively. Determine the concentration of diethylenetriamine in the
Test preparation by comparing the size and intensity of any secondary spot from the chromatogram of the
Test preparation having an
RF value corresponding to the
RF value of diethylenetriamine with the diethylenetriamine spots obtained from the chromatograms of the
Standard preparation mixtures. Determine the concentration of any other observed impurities in the
Test preparation by comparing the size and intensity of any other secondary spots from the chromatogram of the
Test preparation with the 1-(2-aminoethyl)piperazine spots obtained from the chromatograms of the
Standard preparation mixtures.
Part II
Spray reagent
Dissolve 200 mg of ninhydrin in 100 mL of alcohol.
Tris
(2-aminoethyl)amine stock solution[NOTEUse low-actinic glassware.] Dissolve an accurately weighed quantity of tris(2-aminoethyl)amine in methanol to obtain a solution containing 1.0 mg per mL.
Standard preparation A
[NOTEUse low-actinic glassware.
] Dissolve an accurately weighed quantity of
USP Trientine Hydrochloride RS in methanol to obtain a solution containing 10 mg per mL.
Standard preparation B
[NOTEUse low-actinic glassware.] Transfer 1.0 mL of Tris(2-aminoethyl)amine stock solution to a 10-mL volumetric flask, dilute with methanol to volume, and mix.
Standard preparation C
[NOTEUse low-actinic glassware.] Transfer 0.5 mL of Tris(2-aminoethyl)amine stock solution to a 10-mL volumetric flask, dilute with methanol to volume, and mix.
Test preparation
[NOTEUse low-actinic glassware.] Dissolve an accurately weighed quantity of Trientine Hydrochloride in methanol to obtain a solution containing 10 mg per mL.
Procedure
Apply separately 3 µL each of the
Test preparation and of
Standard preparation A to a suitable thin-layer chromatographic plate (see
Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel mixture and previously washed with methanol. To a third spot apply 3 µL each of
Standard preparations A and
B. To a fourth spot, apply 3 µL each of
Standard preparations A and
C. Allow the spots to dry, place the plate in a chromatographic chamber, and develop the chromatograms in a solvent system consisting of a mixture of ammonium hydroxide and alcohol (2:1) at a temperature of 2
to 6
until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the developing chamber, mark the solvent front, and dry the plate with the aid of a current of air. Spray the plate with
Spray reagent, dry at 105
for 5 minutes, and observe the plate under long-wavelength UV light. Determine the concentration of tris(2-aminoethyl)amine in the
Test preparation by comparing the size and intensity of any secondary spot from the chromatogram of the
Test preparation having an
RF value corresponding to the
RF value of tris(2-aminoethyl)amine with the tris(2-aminoethyl)amine spots obtained from the chromatograms of the
Standard preparation mixtures.
Assay
Dissolve about 220 mg of Trientine Hydrochloride, accurately weighed, in 150 mL of water in a 250-mL beaker. Adjust with hydrochloric acid to a pH of 2.0; then adjust with ammonium hydroxide to a pH of 9.5 ± 0.5; and then adjust with glacial acetic acid to a pH of 5.0. Heat the solution to 90
, and while hot, titrate with 0.1 N cupric nitrate VS, determining the endpoint potentiometrically, using an electrode system consisting of a cupric ion-selective electrode and a calomel reference electrode with an outer filling solution of 1
M potassium nitrate. Perform a blank determination (see
Titrimetry 541), and make any necessary correction. Each mL of 0.1 N cupric nitrate is equivalent to 21.92 mg of C
6H
18N
4·2HCl.