Arginine Hydrochloride
C6H14N4O2·HCl 210.66

L-Arginine monohydrochloride.
L-(+)-Arginine monohydrochloride [1119-34-2].
»Arginine Hydrochloride contains not less than 98.5percent and not more than 101.5percent of C6H14N4O2·HCl,calculated on the dried basis.
Packaging and storage— Preserve in well-closed containers.
Identification, Infrared Absorption á197Kñ.
Specific rotation á781Sñ: between +21.4and +23.6(t=20).
Test solution: 80mg per mL,in 6Nhydrochloric acid.
Loss on drying á731ñ— Dry it at 105for 2hours:it loses not more than 0.2%of its weight.
Residue on ignition á281ñ: not more than 0.1%.
Sulfate á221ñ— A1.6-g portion shows no more sulfate than corresponds to 0.50mLof 0.020Nsulfuric acid (0.03%).
Heavy metals,Method Iá231ñ— Proceed as directed except to dissolve 1.0g in 20mLof water,add 2mLof 1Nacetic acid,and dilute with water to 25mL(0.002%).
Change to read:
Chromatographic purity—
Adsorbent: 0.25-mm layer of chromatographic silica gel mixture.
Test solution— Dissolve an accurately weighed quantity of Arginine Hydrochloride in water to obtain a solution having a concentration of 10mg per mL.
Standard solution— Dissolve an accurately weighed quantity of USP Arginine Hydrochloride RSin water to obtain a solution having a known concentration of about 0.05mg per mL.[NOTE—This solution has a concentration equivalent to about 0.5%of that of theTest solution.]
System suitability solution— Prepare a solution in water containing 0.4mg each of USP Arginine Hydrochloride RSand USPL-Lysine Hydrochloride RSper mL.USP28
Spray reagent— Dissolve 0.2g of ninhydrin in 100mLof a mixture of butyl alcohol and 2Nacetic acid (95:5).
Application volume: 5µL.
Developing solvent system— Prepare a mixture of isopropyl alcohol and ammonium hydroxide (70:30).
Procedure— Proceed as directed forThin-Layer ChromatographyunderChromatography á621ñ.Dry the plate between 100and 105until the ammonia disappears completely.Spray withSpray reagent,and heat between 100and 105for about 15minutes.Examine the plate under white light.The chromatogram obtained from theSystem suitability solutionexhibits two clearly separated spots.Any secondary spot in the chromatogram obtained from theTest solutionis not larger or more intense than the principal spot in the chromatogram obtained from theStandard solution:not more than 0.5%of any individual impurity is found,and not more than 2.0%of total impurities is found.
Chloride content— Transfer about 350mg,accurately weighed,to a porcelain casserole,and add 140mLof water and 1mLof dichlorofluorescein TS.Mix,and titrate with 0.1Nsilver nitrate VSuntil the silver chloride flocculates and the mixture acquires a faint pink color.Each mLof 0.1Nsilver nitrate is equivalent to 3.545mg of chloride:between 16.5%and 17.1%is found.
Assay— Dissolve about 100mg of Arginine Hydrochloride,accurately weighed,in 3mLof 98percent formic acid and 50mLof glacial acetic acid.Add 6mLof mercuric acetate TS,and titrate with 0.1Nperchloric acid VS,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 10.53mg of C6H14N4O2·HCl.
Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(DSN)Dietary Supplements:Non-Botanicals
USP28–NF23Page 176
Pharmacopeial Forum:Volume No.30(2)Page 449
Phone Number:1-301-816-8389