Powdered Turmeric Extract
Powdered Turmeric Extract is prepared from the pulverized rhizomes of Curcuma longa L. (Fam. Zingiberaceae), using acetone, methanol, or other suitable solvents. It contains NLT 20% of total curcuminoids, calculated on the dried basis. It may contain other added substances.
•  A. Thin-Layer Chromatographic Identification Test
Standard solution:  0.2 mg/mL of USP Curcuminoids RS in acetone
Sample solution:  10 mg/mL of Powdered Turmeric Extract in acetone
Adsorbent:  0.25-mm layer of chromatographic silica gel mixture, typically 20 cm long (TLC plates)
Application volume:  10 µL, as bands
Developing solvent system:  Chloroform, methanol, and formic acid (96:4:1)
Samples:  Standard solution and Sample solution
Apply the samples as bands to a suitable thin-layer chromatographic plate (see Chromatography 621, Thin Layer Chromatography). Use a saturated chamber. Develop the chromatograms until the solvent front has moved up about three-fourths of the length of the plate. Remove the plate from the chamber, dry, and examine in daylight and under UV light at 365 nm.
Acceptance criteria:  The Sample solution chromatogram shows yellowish-brown bands due to bisdesmethoxycurcumin, desmethoxycurcumin, and curcumin at RF values of about 0.4, 0.6, and 0.7, respectively, corresponding in position and color to those obtained from the Standard solution.
•  B. The retention times of the peaks for curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin of the Sample solution chromatogram correspond to those of the Standard solution for the appropriate USP Reference Standard, as obtained in the test for Content of Curcuminoids.
•  Content of Curcuminoids
Mobile phase:  Tetrahydrofuran and 1 mg/mL of citric acid in water (4:6)
[Note—Sonication may be necessary to dissolve the Reference Standard in each Standard solution; all solutions should be passed through a filter of 0.45-µm pore size before injection. USP Curcumin RS, USP Desmethoxycurcumin, and USP Bisdesmethoxycurcumin RS can also be prepared in one standard solution containing the final concentration specified below for each. ]
Standard solution A:  40 µg/mL of USP Curcuminoids RS in Mobile phase
Standard solution B:  40 µg/mL of USP Curcumin RS in Mobile phase
Standard solution C:  10 µg/mL of USP Desmethoxycurcumin RS in Mobile phase
Standard solution D:  2 µg/mL of USP Bisdesmethoxycurcumin RS in Mobile phase
Sample solution:  Transfer about 100 mg of Powdered Turmeric Extract, accurately weighed, to a 50-mL volumetric flask, add 30 mL of acetone, and sonicate for 30 min. Dilute with acetone to volume and centrifuge. Transfer 5 mL to a 50-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Chromatographic system 
Mode:  LC
Detector:  UV 420 nm
Column:  4.6-mm × 20-cm; 5-µm packing L1
Flow rate:  1 mL/min
Injection size:  20 µL
System suitability 
Sample:  Standard solution A
[Note—The relative retention times for the curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin peaks are 1.0, 1.2, and 1.4, respectively. ]
Suitability requirements 
Chromatogram similarity:  The chromatogram of Standard solution A is similar to the Reference Chromatogram provided with USP Curcuminoids RS.
Resolution:  NLT 2.0, between curcumin and desmethoxycurcumin peaks and the desmethoxycurcumin and bisdesmethoxycurcumin peaks
Tailing factor:  NMT 1.5 for bisdesmethoxycurcumin, desmethoxycurcumin, and curcumin peaks
Relative standard deviation:  NMT 2.0% for desmethoxycurcumin peak, in repeated injections
Samples:  Standard solution A, Standard solution B, Standard solution C, Standard solution D, and Sample solution
Calculate the percentage of curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin in the portion of Powdered Turmeric Extract taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response for curcumin, desmethoxycurcumin, or bisdesmethoxycurcumin from the Sample solution
rS== peak response for curcumin, desmethoxycurcumin, or bisdesmethoxycurcumin from the appropriate Standard solution
CS== concentration of the appropriate Standard solution (mg/mL)
CU== concentration of Powdered Turmeric Extract in the Sample solution (mg/mL)
Add the percentages due to curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin.
Acceptance criteria:  NLT 20% on the dried basis
•  Heavy Metals, Method III 231: NMT 20 ppm
•  Microbial Enumeration Tests 2021: The total aerobic bacterial count does not exceed 104 cfu/g, and the total combined molds and yeasts count does not exceed 103 cfu/g
•  Microbiological Procedures for Absence of Specified Microorganisms 2022: Meets the requirements of the tests for the absence of Salmonella species and Escherichia coli
•  Botanical Extracts, Residual Solvents 565: Meets the requirements
•  Loss on Drying 731: Dry 1.0 g at 105 for 2 h: it loses NMT 7.0% of its weight.
•  Packaging and Storage: Preserve in well-closed containers. Protect from light and moisture, and store at controlled room temperature.
•  Labeling: The label states the Latin binomial and, following the official name, the part of the plant from which the article was prepared. It meets other labeling requirements under Botanical Extracts 565.
•  USP Reference Standards 11
USP Bisdesmethoxycurcumin RS
USP Curcumin RS
USP Curcuminoids RS
USP Desmethoxycurcumin 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
(DS2010) Monographs - Dietary Supplements
2021 Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison
(GCM2010) General Chapters - Microbiology
2022 Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison
(GCM2010) General Chapters - Microbiology
Reference Standards RS Technical Services
USP35–NF30 Page 1459
Pharmacopeial Forum: Volume No. 33(6) Page 1232