Lysine Hydrochloride
C6H14N2O2·HCl
182.65
»Lysine Hydrochloride contains not less than 98.5percent and not more than 101.5percent of C6H14N2O2·HCl,as L-lysine hydrochloride,calculated on the dried basis.
Packaging and storage—
Preserve in well-closed containers.
Identification,Infrared Absorptioná197Kñ.
Specific rotation á781Sñ:
between +20.4
and +21.4.
and +21.4.
Test solution:
80mg per mL,in 6Nhydrochloric acid.
Loss on drying á731ñ—
Dry it at 105for 3hours:it loses not more than 0.4%of its weight.
for 3hours:it loses not more than 0.4%of its weight.
Residue on ignition á281ñ:
not more than 0.1%.
Sulfate á221ñ—
Asolution containing 0.33g shows no more sulfate than corresponds to 0.10mLof 0.020Nsulfuric acid (0.03%).
Iron á241ñ:
0.003%.
Heavy metals,Method Iá231ñ:
0.0015%.
Chromatographic purity—
Adsorbent:
0.25-mm layer of chromatographic silica gel mixture.
Test solution—
Dissolve an accurately weighed quantity of Lysine Hydrochloride in water to obtain a solution having a concentration of 10mg per mL.Apply 5µL.
Standard solution—
Dissolve an accurately weighed quantity of USPL-Lysine Hydrochloride RSin water to obtain a solution having a known concentration of about 0.05mg per mL.Apply 5µL.[NOTE—This solution has a concentration equivalent to about 0.5%of that of the Test solution.]
System suitability solution—
Prepare a solution in water containing 0.4mg each of USPL-Lysine Hydrochloride RSand USP Arginine Hydrochloride RSper mL.Apply 5µL.
Spray reagent—
Dissolve 0.2g of ninhydrin in 100mLof a mixture of butyl alcohol and 2Nacetic acid (95:5).
Developing solvent system—
Prepare a mixture of isopropyl alcohol and ammonium hydroxide (70:30).
Procedure—
Proceed as directed for Thin-Layer Chromatographyunder Chromatography á621ñ.Dry the plate between 100and 105until the ammonia disappears completely.Spray with Spray reagent,and heat between 100and 105for about 15minutes.Examine the plate under white light.The chromatogram obtained from the System suitability solutionexhibits two clearly separated spots.Any secondary spot in the chromatogram obtained from the Test solutionis not larger or more intense than the principal spot in the chromatogram obtained from the Standard solution:not more than 0.5%of any individual impurity is found;and not more than 2.0%of total impurities is found.
and 105until the ammonia disappears completely.Spray with Spray reagent,and heat between 100and 105for about 15minutes.Examine the plate under white light.The chromatogram obtained from the System suitability solutionexhibits two clearly separated spots.Any secondary spot in the chromatogram obtained from the Test solutionis not larger or more intense than the principal spot in the chromatogram obtained from the Standard solution:not more than 0.5%of any individual impurity is found;and not more than 2.0%of total impurities is found.
Organic volatile impurities,Method Iá467ñ:
meets the requirements.
Content of chloride—
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 19.0%and 19.6%is found.
Assay—
Transfer about 90mg of Lysine Hydrochloride,accurately weighed,to a 125-mLflask,and dissolve in a mixture of 3mLof formic acid and 50mLof glacial acetic acid.Add 10mLof 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 9.133mg of C6H14N2O2·HCl.
Auxiliary Information—
Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(DSN)Dietary Supplements:Non-Botanicals
USP28–NF23Page 1159
Phone Number:1-301-816-8389