A: The retention times of the major peaks in the chromatogram of the Test solutioncorrespond to those in the chromatogram of the Standard solution,as obtained in the test for Content of glucosamine (presence of glucosamine).

B:Standard solution andTest solution— Prepare as directed in the test for Content of chondroitin sulfate sodiumunder Chondroitin Sulfate Sodium Tablets.

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Medium: water;900mL.

Apparatus 2: 75rpm.

Time: 60minutes.

Diluent,0.2M Borate buffer,Derivatizing reagent,Mobile phase,and Chromatographic system— Proceed as directed in the test for Content of glucosamine.

Standard solution— Prepare as directed in the test for Content of glucosamine.Dilute with a suitable quantity of water,if necessary.

Test solution— Use the solution under test.

Procedure— Proceed as directed in the test for Content of glucosamine.Calculate the quantity,in mg,of glucosamine (C6H13NO5)dissolved by the formula: in which the terms are as defined therein.

Tolerances— Not less than 75%of the labeled amount of C6H13NO5is dissolved in 60minutes.

Cetylpyridinium chloride solution,Diluent,Standard solutions,and Test solutionUSP28— Prepare as directed in the test for Content of chondroitin sulfate sodium under Chondroitin Sulfate Sodium Tablets.USP28

Procedure— Proceed as directed in the test for Content of chondroitin sulfate sodium under Chondroitin Sulfate Sodium Tablets,USP28adjusting the volume of the sample and/or the concentrations of the standards,USP28if necessary.Calculate the quantity,in mg,of chondroitin sulfate sodium dissolved by the formula: in which Cis the concentration,in mg per mL,of chondroitin sulfate sodium in the solution under test.

Tolerances— Not less than 75%of the labeled amount of chondroitin sulfate sodium is dissolved in 60minutes.

Diluent— Transfer 29µLof acetic acid and 5mLof acetonitrile to a 100-mLvolumetric flask containing about 50mLof water,and dilute with water to volume.

0.2M Borate buffer— Dissolve 7.63g of sodium borate in 80mLof water,and adjust with hydrochloric acid TSto a pHof 9.5.Transfer to a 100-mLvolumetric flask,dilute with water to volume,and mix.[NOTE—Buffer must be stored at room temperature and can be used indefinitely,but must be warmed to dissolve if crystallization occurs.]

Derivatizing reagent— In a 14-mLpolypropylene culture tube,dissolve 50mg of o-phthalaldehyde in 1.25mLof anhydrous methanol,add 50µLof 3-mercaptopropionic acid and 11.2mLof 0.2M Borate buffer,and mix gently.Allow to stand in the dark for 30minutes before use.[NOTE—Reagent strength is maintained by adding 10µLof 3-mercaptopropionic acid every two days.Storage should be in the dark,at room temperature,and can be used for not more than 2weeks.]

Mobile phase— In a 1000-mLvolumetric flask dissolve 6.80g of sodium acetate trihydrate in 700mLof water.Adjust with dilute acetic acid to a pHof 5.9,dilute with water to volume,and mix.Combine 100mLof methanol with 900mLof acetate buffer,and mix thoroughly.Pass through a nylon membrane filter having a 0.45-µm or finer porosity,and degas.Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).

Standard solution— Dissolve an accurately weighed quantity of USP Glucosamine Hydrochloride RSin water,and dilute quantitatively,and stepwise if necessary,with water to obtain a solution having a known concentration of about 1.0mg per mL.Allow to stand at room temperature for 1hour.

Test solution— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 25mg of glucosamine,to a 25-mLvolumetric flask,and dilute with Diluentto volume.Mix on a vortex mixer to suspend the powder in solution.Sonicate in a 65water bath for 20minutes.Remove from the bath,stir for 5minutes with the aid of a magnetic stirrer,and centrifuge.

Chromatographic system— The liquid chromatograph is equipped with a 340-nm detector and a 3.0-mm ×5-cm column that contains packing L1.The flow rate is about 1.0mLper minute.Chromatograph five individual aliquots of the Standard solution derivatized as directed for Procedure.Each derivatized aliquot is injected only once.The relative retention times are 1.0for the b-anomer and 1.8for the a-anomer,and the typical retention time of the b-anomer is not less than 4minutes.The relative standard deviation calculated from these five replicates is not more than 2.0%.

Procedure— Transfer 100µLof the Derivatizing reagentand 100µLof the Standard solutionor the Test solutionto a vial containing 400µLof 0.2M Borate buffer,mix,allow the derivatization to proceed for 1minute,and inject the derivatized solution into the chromatograph.Separately inject equal volumes (about 10µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the responses for the major peaks.[NOTE—Inject the derivatized solution immediately after the derivatization reaction.]Calculate the quantity,in mg,of glucosamine (C6H13NO5)in the portion of Tablets taken by the formula: in which 179.17and 215.63are the molecular weights of glucosamine and glucosamine hydrochloride,respectively;Cis the concentration,in mg per mL,of USP Glucosamine Hydrochloride RSin the Standard solution;and rUand rSare the peak responses for the b-anomer obtained from the Test solutionand the Standard solution,respectively.

Change to read:

Cetylpyridinium chloride solution,Diluent,Standard solutions,USP28Test solution,and Procedure— Proceed as directed in the test for Content of chondroitin sulfate sodiumunder Chondroitin Sulfate Sodium Tablets.