Glucosamine Tablets
DEFINITION
Glucosamine Tablets are prepared from Glucosamine Hydrochloride, Glucosamine Sulfate Sodium Chloride, Glucosamine Sulfate Potassium Chloride, or a mixture of any of them. Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of glucosamine (C6H13NO5).
IDENTIFICATION
•  A. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the test for Content of Glucosamine.
•  B. Identification Tests—General, Chloride 191: Meets the requirements
•  C. Identification Tests—General, Sulfate 191: Meets the requirements. [Note—Only for Tablets labeled as containing glucosamine sodium sulfate or glucosamine potassium sulfate ]
STRENGTH
•  Content of Glucosamine
Buffer:  In a 1-L volumetric flask dissolve 3.5 g of dibasic potassium phosphate in water. Add 0.25 mL of ammonium hydroxide, dilute with water to volume, and mix. Adjust with phosphoric acid to a pH of 7.5.
Mobile phase:  Acetonitrile and Buffer (75:25)
Diluent:  Acetonitrile and water (50:50)
Standard solution:  3.75 mg/mL of USP Glucosamine Hydrochloride RS in Diluent
Sample solution:  Weigh and finely powder NLT 20 Tablets. Transfer an accurately weighed portion of the finely powdered material, equivalent to about 312 mg of glucosamine, to a 100-mL volumetric flask. Add 60 mL of Diluent, and sonicate for 10 min. Shake by mechanical means for 15 min. Dilute with Diluent to volume, and mix. Pass a portion of this solution through a membrane filter of 0.45-µm or finer pore size.
Chromatographic system 
Mode:  LC
Detector:  UV 195 nm
Column:  4.6-mm × 15-cm; 5-µm packing L8
Column temperature:  35
Flow rate:  1.5 mL/min
Injection size:  10 µL
[Note—The peak for glucosamine moiety elutes at about 10 min. The chromatogram shows a large additional peak near the void volume, due to the chloride ion. ]
System suitability 
Sample:  Standard solution
Suitability requirements 
Tailing factor:  NMT 2.0 for the glucosamine peak
Column efficiency:  NLT 1500 theoretical plates
Relative standard deviation:  NMT 2.0%
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of the labeled amount of glucosamine (C6H13NO5) in the portion of Tablets taken:
Result = (rU/rS) × (CS/CU) × (Mr1/Mr2) × 100
rU== peak response of glucosamine from the Sample solution
rS== peak response of glucosamine from the Standard solution
CS== concentration of USP Glucosamine Hydrochloride RS in the Standard solution (mg/mL)
CU== nominal concentration of glucosamine in the Sample solution (mg/mL)
Mr1== molecular weight of glucosamine, 179.17
Mr2== molecular weight of glucosamine hydrochloride, 215.63
Acceptance criteria:  90.0%–110.0%
PERFORMANCE TESTS
•  Disintegration and Dissolution of Dietary Supplements 2040: Meet the requirements for Dissolution
Medium:  Water; 900 mL
Apparatus 2:  75 rpm
Time:  60 min
Standard solution:  Dissolve a suitable amount of USP Glucosamine Hydrochloride RS in water to obtain a concentration similar to that expected in the Sample solution.
Sample solution:  Filtered portion of the solution under test
Buffer:  Mix 1.0 mL of phosphoric acid with 2 L of water, and adjust with potassium hydroxide to a pH of 3.0.
Mobile phase:  Acetonitrile and Buffer (2:3)
Chromatographic system 
Mode:  LC
Detector:  UV 195 nm
Column:  4.6-mm × 25-cm; packing L7
Flow rate:  0.6 mL/min
Injection size:  10 µL
System suitability 
Sample:  Standard solution
Suitability requirements 
Tailing factor:  NMT 2.0 for the glucosamine peak
Relative standard deviation:  NMT 2.0%
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of the labeled amount of glucosamine (C6H13NO5) dissolved:
Result = (rU/rS) × (CS × V/L) × (Mr1/Mr2) × 100
rU== peak area from the Sample solution
rS== peak area from the Standard solution
CS== concentration of USP Glucosamine Hydrochloride RS in the Standard solution (mg/mL)
V== volume of Medium, 900 mL
L== labeled amount of glucosamine (mg/Tablet)
Mr1== molecular weight of glucosamine, 179.17
Mr2== molecular weight of glucosamine hydrochloride, 215.63
Tolerances:  NLT 75% of the labeled amount of glucosamine (C6H13NO5) is dissolved.
•  Weight Variation of Dietary Supplements 2091: Meet the requirements
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in tight, light-resistant containers.
•  Labeling: The label indicates the type of glucosamine salt contained in the article.
•  USP Reference Standards 11
USP Glucosamine Hydrochloride RS Click to View Structure
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Natalia Davydova
Scientific Liaison
1-301-816-8328
(DS2010) Monographs - Dietary Supplements
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 1335
Pharmacopeial Forum: Volume No. 32(4) Page 1137