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          Turmeric Dry Extract is prepared from the powdered Turmeric by extraction with ethanol. It contains not less than 90.0 per cent and not more than 110.0 per cent of the labelled amount of curcuminoids; the labelled amount of curcuminoids is not less than 80.0 per cent, calculated as curcumin (C₂₁H₂₀O₆) and on the dried basis. It may contain other added substances.

Description Yellow to brownish orange powder; slightly hygroscopic.

Packaging and storage Turmeric Dry Extract shall be kept in tightly closed containers, protected from light, and stored in a cool and dry place.

Labelling The label on the container states (1) the equivalent amount of curcuminoids as curcumin; (2) the expiration date.

Identification Carry out the test as described in the “Thin-Layer Chromatography” (Appendix 3.1), using silica gel GF254 as the coating substance and a mixture of 96 volumes of chloroform, 4 volumes of methanol and 1 volume of formic acid as the mobile phase. Apply separately to the plate as bands of 10 mm, 10 μl each of the following two solutions. For solution (A), dissolve 100 mg of the sample in 50 mL of acetone. Solution (B) contains 200 μg per mL of curcuminoids in acetone. After removal of the plate, allow it to dry in air and examine under daylight. Three yellow bands are observed. Examine under ultraviolet light (366 nm). The chromatogram obtained from solution (A) shows three bluish green bands corresponding to the bisdesmethoxycurcumin, desmethoxycurcumin and curcumin bands from solution (B), in the order of increasing hR_f values.

Loss on drying Not more than 7.0 per cent w/w after drying at 105° for 2 hours (Appendix 4.15). Use 1.0 g

Assay Carry out the determination as described in the “Ultraviolet and Visible Spectrophotometry” (Appendix 2.2).

          Standard curcumin solution Dissolve an accurately weighed quantity of Curcumin RS in methanol. Dilute quantitatively and stepwise with methanol to obtain a solution having a known concentration of about 16 μg of curcumin per mL.

          Standard curcumin curve Transfer into five 25-mL volumetric flasks, 1.0, 2.0, 3.0, 4.0, and 5.0 mL of Standard curcumin solution, dilute to volume with methanol, and mix. Measure the absorbances of the standard solutions at the maximum at about 420 nm, using methanol as the blank (Appendix 2.2). Plot the readings and draw the curve of best fit: the curve shows the correlation coefficient of not less than 0.995.

          Assay preparation Transfer about 60 mg of Turmeric Dry Extract, accurately weighed, to a 100-mL volumetric flask, add 75 ml of methanol and sonicate for 15 minutes. Dilute to volume with methanol and mix. Pipette 2 mL of the solution into a 50-mL volumetric flask, dilute to volume with methanol and mix. Dilute 3.0 mL of the resulting solution with methanol to produce 25.0 mL and mix. Prepare three replicate samples for each analysis: the relative standard deviation is not more than 2.0 per cent.

         Procedure and Calculation Measure the absorbance of Assay preparation at the maximum at about 420 nm, using methanol as the blank (Appendix 2.2). By reference to the Standard curcumin curve, calculate the content of curcuminoids as curcumin (C₂₁H₂₀O₆) in the portion of the Extracts taken.

Other requirements Complies with the requirements described under “Extracts” (Appendix 1.16H).