Mucuna pruriens Seed Powder

Mucuna pruriens Seed Powder

Proposed For Development Version 0.1


Mucuna pruriens Seed Powder




The article consists of the dried seeds of Mucuna pruriens (L.) DC. (Family Fabaceae), reduced to a fine or very fine powder. It contains NLT 3.0% of levodopa on the dried basis.



None known



Amino acid: Levodopa

Alkaloids: Mucunine, mucunadine, prurienidine, and prurieninine



• A. Botanical Characteristics

Macroscopic: Pale cream-colored powder

Microscopic: Shows fragments of testa with palisade-like cells thin-walled parenchyma, reticulate and pitted vessels, aleurone and starch grains small, simple, rounded to oval measuring 6–41 μm in diameter, but not over 45 μm in diameter.

• B. Thin-Layer Chromatography

Standard solution A: 0.5 mg/mL of USP Levodopa RS in 30% phosphoric acid

Standard solution B: Sonicate 500 mg of USP Mucuna pruriens Seed Dry Extract RS with 10 mL of 30% phosphoric acid for 5 min. Transfer the solution to a 50-mL volumetric flask and add methanol to volume. Centrifuge or filter, and use the supernatant or the filtrate.

Sample solution: Deposit 1 g of Mucuna pruriens Seed Powder into a suitable beaker, and add 10 mL of 30% phosphoric acid. Sonicate for 5 min, and transfer to a 50-mL volumetric flask. Rinse the beaker with methanol and empty the rinsate into the same flask. Dilute with methanol to volume. Centrifuge or filter, and use the supernatant or the filtrate.

Chromatographic system

(See Chromatography <621>, Thin-Layer Chromatography.)

Adsorbent: Chromatographic silica gel F254 mixture with an average particle size of 5 µm

Application volume: 10 µL each of Standard solution AStandard solution B, and Sample solution; as 8-mm bands

Relative humidity: Condition the plate to a relative humidity of about 33% using a suitable device

Developing solvent system: Butanol, alcohol, acetic acid, and water (60:32:12:8)

Developing distance: 8 cm

Derivatization reagent: Use a suitable reagent, if applicable.


Samples: Standard solution A, Standard solution B, and Sample solution

Apply the Samples as bands and dry in air. Develop in a saturated chamber (20 min with filter paper), remove the plate from the chamber, and dry in air. Treat the plate with the Derivatization reagent, heat at 100° for 5 min, and examine under white light.

System suitability: Under white light, the chromatogram of Standard solution B exhibits the most intense dark gray or black band with similar RF and color as the levodopa band in the chromatogram of Standard solution A. Three to four dark pink bands appear below the levodopa band and one strong and two weak dark pink bands appear above the levodopa band.

Acceptance criteria: Under white light, the chromatogram of the Sample solution exhibits the most intense dark gray or black band  in the middle of the chromatogram, corresponding in RF to the levodopa band in Standard solution A. The Sample solution exhibits additional bands corresponding to similar bands in Standard solution B, in particular, two weak pink bands: one above and one below levodopa band.


Analysis: Proceed as directed in the test for Content of Levodopa.

Acceptance criteria: The Sample solution exhibits the most intense peak at a retention time corresponding to the peak due to levodopa in Standard solution A and Standard solution B.



Content of Levodopa

Solution A: 1.36 g of monobasic potassium phosphate in 900 mL of water and adjust with phosphoric acid to a pH of 2.5.

Solution B: Methanol

Mobile phase: A mixture of Solution A and Solution B (92:8)

Standard solution A: Dissolve 20 mg of USP Levodopa RS with 5 mL of 30% phosphoric acid and 5 mL of water in a 100-mL volumetric flask. Diute with water to volume.

Standard solution B: Weigh accurately a sample quantity equivalent to 20 mg of levodopa to a 100-mL volumetric flask. Add 5 mL of 30% phosphoric acid and 5 mL of water, sonicate for 6 min, make up to volume, and centrifuge. Before injection, pass through a membrane filter of 0.45-µm or finer pore size

Sample solution: Transfer about 2.5 g of Mucuna pruriens Seed Powder, accurately weighed, into a 100-mL centrifuge tube, and add 25 mL of 9% phosphoric acid. Sonicate for 5 min, centrifuge at 3000 rpm for 5 min, and transfer the supernatant to a 100-mL volumetric flask. Repeat the extraction three more times by adding 20 mL of 9% phosphoric acid, and transferring the supernatant to the same 100-mL volumetric flask; dilute with 9% phosphoric acid to volume, and mix. Before injection, pass through a polyethersulfone membrane filter of 0.45-µm or finer pore size and discard the first portion of the filtrate.

Chromatographic system

(See Chromatography <621>, System Suitability.)

Detector: LC

Column: 4.6-mm × 25-cm; 5-µm packing L1

Column temperature: 30°

Flow rate: 1.0 mL/min

Injection volume: 20 µL

System suitability

Samples: Standard solution A and Standard solution B

Suitability requirements

Resolution: NLT 1.5 between levodopa and the peak before it, Standard solution B

Tailing factor: NMT 1.5 for the levodopa peak, Standard solution A

Relative standard deviation: NMT 2.0% for the levodopa peak in repeated injections, Standard solution A

Chromatogram similarity: The chromatogram of Standard solution B is similar to the reference chromatogram provided with the lot of USP Mucuna pruriens Seed Dry Extract RS being used.


Samples: Standard solution AStandard solution B, and Sample solution

Using the chromatograms of Standard solution A, Standard solution B, and the reference chromatogram provided with the lot of USP Mucuna pruriens Seed Dry Extract RS being used, identify the retention times of the peaks corresponding to the peaks due to levodopa in the Sample solution.

Calculate the percentage of levodopa in the portion of Mucuna pruriens Seed Powder taken:


Result = (rU/rS) × CS × (V/W) × 100


rU   = peak area of levodopa from the Sample solution

rS   = peak area of levodopa from the Standard solution A

CS  = concentration of the USP Levodopa RS in Standard solution A (mg/mL)

V   = volume of the Sample solution (mL)

W   = weight of Mucuna pruriens Seed Powder taken to prepare the Sample solution (mg)

Acceptance criteria: NLT 3.0% of levodopa on the dried basis



• Elemental Impurities—Procedures <233>

Acceptance criteria

Arsenic: NMT 2.0 µg/g

Cadmium: NMT 0.5 µg/g

Lead: NMT 5 µg/g

Mercury: NMT 0.2 µg/g

• Articles of Botanical Origin <561>, Pesticide Residue Analysis: Meets the requirements

• Microbial Enumeration Tests <61>: The total aerobic bacterial count does not exceed 105 cfu/g, the total combined molds and yeasts count does not exceed 103 cfu/g, and the bile-tolerant Gram-negative bacteria does not exceed 103 cfu/g.

• Tests for Specified Microorganisms <62>: Meets the requirements of the tests for the absence of Salmonella species and Escherichia coli



• Articles of Botanical Origin <561>, Methods of Analysis, Foreign Organic Matter: NMT 1.0%

• Articles of Botanical Origin <561>, Methods of Analysis, Alcohol-Soluble ExtractivesMethod 1: NLT 3.0%

• Articles of Botanical Origin <561>, Methods of Analysis,  Water-Soluble ExtractivesMethod 2: NLT 23.0%

• Water Determination <921>Method II: NMT 8.0% 

• Articles of Botanical Origin <561>, Methods of Analysis, Total Ash:  NMT 5.0%

• Articles of Botanical Origin <561>, Methods of Analysis, Acid-Insoluble Ash: NMT 1.0%



• Packaging and Storage: Preserve in well-closed containers, protected from light and moisture, and store at room temperature.

• Labeling: The label states the Latin binomial and the part(s) of the plant contained in the article.

• USP Reference Standards <11>

USP Levodopa RS

USP Mucuna pruriens Seed Dry Extract RS

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