Packaging and storage—
Preserve in tight, light-resistant, glass containers.
Identification—
B:
To 1 mL of 1 in 10,000 solution in alcohol in a glass-stoppered test tube add 1 mL of pH 4.0 acid phthalate buffer (see under
Solutions in the section
Reagents, Indicators, and Solutions), 1 mL of a 1 in 20 solution of 4-(
p-nitrobenzyl)pyridine in acetone, and 1 mL of
saline TS. Heat on a water bath at 80
for 20 minutes, and cool quickly. Add 10 mL of alcohol and 1 mL of 1 N potassium hydroxide: a violet to red-violet color is produced.
C:
Heat 100 mg with 10 mL of 0.1 N sodium hydroxide on a water bath for 10 minutes: the resulting solution, after acidification with 2 N nitric acid, responds to the tests for
Chloride 
191
.
Specific rotation 781S:
between
30
and
36
.
Test solution:
7 mg per mL, in methanol, prepared with the aid of gentle heating.
Loss on drying 731:
Dry it in vacuum at 105
to constant weight: it loses not more than 7.0% of its weight.
Ionizable chlorine—
Dissolve about 500 mg of Melphalan, accurately weighed, in a mixture of 75 mL of water and 2 mL of nitric acid, allow to stand for 2 minutes, and titrate with 0.1 N silver nitrate VS, determining the endpoint potentiometrically: not more than 1.0 mL of 0.1 N silver nitrate is required for each 500 mg of test specimen.
Nitrogen content 461—
Determine the nitrogen content as directed under
Method II, using about 325 mg of Melphalan, accurately weighed, and 0.1 N sulfuric acid VS for the titration: not less than 8.90% and not more than 9.45% of N is found, calculated on the dried basis.
Organic volatile impurities, Method IV 467:
meets the requirements.
Assay—
Transfer to a beaker about 200 mg of Melphalan, accurately weighed, and dissolve in 20 mL of 0.5 N sodium hydroxide. Cover the beaker with a watch glass, and boil the solution for 30 minutes, adding water as necessary to maintain the volume. Cool, neutralize to
phenolphthalein TS with acetic acid, and add 1 mL of acetic acid in excess. Titrate with 0.1 N silver nitrate VS, determining the endpoint potentiometrically, using silver and calomel electrodes, the latter modified to contain saturated potassium sulfate solution. From the results obtained in the test for
Ionizable chlorine, calculate the volume, in mL, of 0.1 N silver nitrate that is equivalent to the ionizable chlorine in the quantity of Melphalan taken for the
Assay, and subtract it from the
Assay titration volume. Each mL of 0.1 N silver nitrate is equivalent to 15.26 mg of C
13H
18Cl
2N
2O
2.
;)
