Ginger Tincture
DEFINITION
Ginger Tincture is prepared as follows.
Ginger 200 g
A mixture of Alcohol and Water (7:3),
a sufficient quantity to make
1000 mL
Prepare the Tincture as directed for Botanical Extracts 565, Tinctures, Maceration Process. It contains NLT 0.10% of gingerols.
IDENTIFICATION
•  Thin-Layer Chromatographic Identification Test
Standard solution A:  Transfer 0.2 g of USP Powdered Ginger RS to a test tube, add 5 mL of methanol, shake for 30 min, and centrifuge. Apply the supernatant to the plate.
Standard solution B:  Use the System suitability solution, prepared as directed in the test for Content of Gingerols.
Sample solution:  Tincture
Adsorbent:  0.50-mm layer of chromatographic silica gel mixture
Application volume:  20 µL for the Sample solution and Standard solution A; 40 µL for Standard solution B
Developing solvent system:  Ethyl ether and hexane (7:3)
Spray reagent:  10% sulfuric acid in alcohol
Analysis 
Samples:  Standard solution A, Standard solution B, and Sample solution
Develop the chromatograms until the solvent front has moved up about three-fourths of the plate. Remove the plate from the chamber and dry. Examine the plate under UV light at 254 nm. Spray the plate with Spray reagent, heat at 100–105 for 10 min, and examine under daylight.
Acceptance criteria:  The chromatogram of the Sample solution exhibits a spot due to gingerols that occurs at an RF value of 0.2, and a spot of shogaols may occur at an RF value of 0.4, corresponding to the chromatogram of Standard solution B. [Note—The chromatograms of the Sample solution and Standard solution A may exhibit other spots in the upper region and at the origin of the plate. ]
STRENGTH
•  Content of Gingerols
Solution A:  Acetonitrile, dilute phosphoric acid (1 in 1000), and methanol (55:44:1)
Solution B:  Acetonitrile
Mobile phase:  Use Solution A for NLT seven times the retention time of capsaicin.
Column washing:  After each chromatographic run, wash the column, using Table 1.
Table 1
Time
(min)
Solution A (%) Solution B (%)
0 100 0
2 0 100
12 0 100
14 100 0
29 100 0
Standard solution:  0.1 mg/mL of USP Capsaicin RS in methanol
Sample solution:  Tincture
System suitability solution:  Reconstitute the content of 1 vial of USP Ginger Constituent Mixture RS in 1 mL of Standard solution.
Chromatographic system 
Mode:  LC
Detector:  UV 282 nm
Column:  4.6-mm × 25-cm; packing L1
Flow rate:  1 mL/min
Injection size:  25 µL
System suitability 
Samples:  Standard solution and System suitability solution
[Note—The relative retention times for 6-gingerol, capsaicin, and 6-shogaol are about 0.8, 1.0, and 1.9, respectively, System suitability solution. ]
Suitability requirements 
Resolution:  NLT 3.0 between the 6-gingerol and capsaicin peaks and NLT 10.0 between the capsaicin and 6-shogaol peaks, System suitability solution
Tailing factors:  NMT 2.0 for the 6-gingerol, capsaicin, and 6-shogaol peaks, System suitability solution
Relative standard deviation:  NMT 2.5%, Standard solution
Analysis 
Samples:  Standard solution, Sample solution, and System suitability solution
Calculate the percentage of gingerols in the portion of Tincture taken:
Result = (rU/rS) × CS × 0.1
rU== sum of the peak responses of gingerols from the Sample solution
rS== peak response of capsaicin from the Standard solution
CS== concentration of USP Capsaicin RS in the Standard solution (mg/mL)
Acceptance criteria:  NLT 0.10%
OTHER COMPONENTS
•  Alcohol Determination, Method I 611: NLT 90.0% and NMT 110.0% of the labeled amount of C2H5OH
CONTAMINANTS
•  Arsenic, Method II 211: NMT 1 ppm
•  Heavy Metals, Method III 231: NMT 10 µg/g
•  Microbial Enumeration Tests 2021: The total aerobic microbial count does not exceed 104 cfu/g, and the total combined molds and yeasts count does not exceed 103 cfu/g.
SPECIFIC TESTS
•  Limit of 6-Shogaol
Analysis:  Using the chromatograms from the test for Content of Gingerols, calculate the percentage of 6-shogaol in the portion of Tincture taken:
Result = (rU/rS) × CS × 0.1
rU== peak response of 6-shogaol from the Sample solution
rS== peak response of capsaicin from the Standard solution
CS== concentration of USP Capsaicin RS in the Standard solution (mg/mL)
Acceptance criteria:  NMT 0.034%
•  Limit of Nonvolatile Residue: Evaporate a 10-mL portion in a tared platinum or porcelain dish, and dry at 105 for 6 h: the weight of the residue is 80–120 mg.
•  Specific Gravity 841: 0.90–0.95
•  Other Requirements: Meets the requirements in Botanical Extracts 565, Packaging, and Storage
ADDITIONAL REQUIREMENTS
Change to read:
•  Labeling: Label it to indicate that it is for manufacturing purposes only, in addition to the information specified in Botanical Extracts 565, Tinctures, Labeling. This article is exempted from the requirements of the General Notices with respect to the pregnancy and lactation statement (section 10.40.50. Labeling Botanical-Containing Products).USP35
•  USP Reference Standards 11
USP Capsaicin RS Click to View Structure
USP Ginger Constituent Mixture RS
USP Powdered Ginger RS
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Maged H. Sharaf, Ph.D.
Principal Scientific Liaison
1-301-816-8318
(DS2010) Monographs - Dietary Supplements
2021 Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison
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USP35–NF30 Page 1322
Pharmacopeial Forum: Volume No. 36(6) Page 1601