Rhodiola crenulata Root and Rhizome Powder

Rhodiola crenulata Root and Rhizome Powder

Proposed For Comment Version 0.2

Rhodiola crenulata Root and Rhizome Powder

 


 

DEFINITION

The article consists of the dried roots and rhizomes of Rhodiola crenulata (Hook. f. et Thomson) H. Ohba (Family Crassulaceae), collected after the scape wither in autumn, reduced to a fine or very fine powder. It contains NLT 1.0% of total phenylethanoids, calculated as the sum of salidroside (C14H20O7) and tyrosol (C8H10O2) on the dried basis; NLT 0.6% of salidroside on the dried basis.

 

POTENTIAL CONFOUNDING MATERIALS

Rhodiola calliantha (H. Ohba) H. Ohba

Rhodiola cretinii (Hamet) H. Ohba

Rhodiola dumulosa (Franch.) S. H. Fu

Rhodiola heterodonta (HK. f. et Thoms.) A. Bor.

Rhodiola kirilowii (Regel) Maxim.

Rhodiola linearifolia A. Bor.

Rhodiola quadrifida (Pall.) Fisch. et Mey.

Rhodiola robusta (Praeg.) S. H. Fu

Rhodiola rosea L.

Rhodiola sachalinensis A. Bor.

Rhodiola serrata H. Ohba

 

CONSTITUENTS OF INTEREST

Phenylethanoids: Salidroside and tyrosol

Benzoic acid: Gallic acid

 

IDENTIFICATION

• A. Botanical Characteristics

Macroscopic: Pinkish-brown or light reddish brown powder

Microscopic: Cork cell fragments sub-rectangular or polygonal, containing yellowish-brown pigments, 10–150 μm in diameter. Spiral vessels are 6–58 μm in diameter. Fibers mostly in bundles, long fusiform with oblique or blunt-round ends and striations, 10–60 μm in diameter. Parenchymatous cells are square or irregular, 2–20 μm in diameter, containing the calcium oxalate prim crystals. Abundant simple starch grains rounded with indistinct hilum and stration, 2–10 μm in diameter.

• B. HPTLC

(See HPTLC for Identification of Articles of Botanical Origin <203>.)

Standard solution: 2.0 mg/mL of USP Salidroside RS and 1.0 mg/mL of USP Rosavin RS in methanol

Sample solution: Sonicate 0.5 g of Rhodiola crenulata Root and Rhizome Powder in 5 mL of methanol for 10 min, centrifuge, and use the supernatant.

Chromatographic system

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

Application volume: 5 µL, as 8-mm bands

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

Developing solvent system: Ethyl acetate, methanol, water, and formic acid (77:13:10:2)

Developing distance: 6 cm

Derivatization reagent: Dissolve 1 g of diphenylamine in 40 mL of acetone; add 1 mL of aniline, and mix. Carefully add 7.5 mL of phosphoric acid, and mix.

Analysis

Samples: Standard solution and Sample solution

Apply the Samples as bands and dry in air. Develop in a saturated chamber, remove the plate from the chamber, and dry in air. Treat with Derivatization reagent, heat at 120º for 5 min, and examine under visible light.

System suitability: The Standard solution shows two gray bands at lower half of the chromatogram. The band with a higher RF is due to salidroside, and the band with a lower RF is due to rosavin.

Acceptance criteria: The Sample solution exhibits a gray band corresponding in RF and color to the salidroside band in Standard solution. In the Sample solution, no band corresponding in RF and color to the rosavin band in Standard solution is observed (a distinction from Rhodiola rosea Root and Rhizome). The Sample solution exhibits additional bands, including other two gray bands which between positions of salidroside and rosavin bands, two yellow bands at upper half part, and a couple of gray bands close to the starting position.

• C. HPLC

Analysis: Proceed as directed in the Assay for Content of Phenylethanoids.

Acceptance criteria: The chromatogram of the Sample solution exhibits a peak with a retention time corresponding to the peak due to salidroside in the Standard solution, a peak due to tyrosol with lower intensity than the peak of salidroside, and a peak due to gallic acid. The peak area ratio of salidroside to tyrosol is not lower than 2.

 

ASSAY

• Content of Phenylethanoids

Solution A: 0.02% Phosphoric acid in water

Solution B: Methanol and acetonitrile (9:1)

Mobile phase: See Table 1.

 

Table 1

Time
(min)

Solution A
(%)

Solution B
(%)

0

95

5

10

95

5

15

83

17

28

83

17

28.1

10

90

43

10

90

43.1

95

5

53

95

5

 

Solvent: Methanol and water (6:4)

Standard solution: 0.3 mg/mL of USP Salidroside RS in methanol

Sample solution: Accurately transfer about 500 mg of Rhodiola crenulata Root and Rhizome Powder to a 50-mL stoppered conical flask and accurately add 15 mL of Solvent. Weigh the filled flask with a precision of ± 0.1 mg and then sonicate for 30 min. Cool to room temperature, adjust to the initial weight by adding Solvent if needed. Before injection, pass through a membrane filter of 0.45-μm or finer pore size, and discard the first part of the filtrate.

Chromatographic system

(See Chromatography <621>, System Suitability.)

Mode: LC

Detector: UV 275 nm

Column: 4.6-mm × 25-cm; 5-μm packing L1 (similar to Merck Purospher STAR RP-18)

Column temperature: 25°

Flow rate: 1.0 mL/min

Injection volume: 10 µL

System suitability

Samples: Standard solution and Sample solution

Suitability requirements

Resolution: NLT 1.5 between salidroside and tyrosol peaks, Sample solution

Tailing factor: NMT 1.5 for the salidroside peak, Standard solution

Relative standard deviation: NMT 2.0% for the salidroside peak, Standard solution

Analysis

Samples: Standard solution and Sample solution

Using the chromatogram of the Standard solution and the relative retention times, identify the retention times of the peaks corresponding to gallic acid, salidroside, and tyrosol in the Sample solution. [Note—The approximate relative retention times for the peaks of gallic acid, salidroside, and tyrosol are 0.48, 1.00, and 1.05, respectively.]

Separately calculate the percentages of salidroside and tyrosol in the portion of Rhodiola crenulata Root and Rhizome Powder taken:

 

Result = (rU/rS) × CS × (V/W) × F × 100

 

rU   = peak area of the relevant analyte from the Sample solution

rS   = peak area of salidroside from the Standard solution

C = concentration of USP Salidroside RS in the Standard solution (mg/mL)

V    = volume of the Sample solution (mL)

W   = weight of Rhodiola crenulata Root and Rhizome Powder taken to prepare the Sample solution (mg)

F    = conversion factors for the analytes; 1.00 for salidroside, 0.43 for tyrosol

 

Calculate the content of total phenylethanoids as the sum of the percentages of salidroside and tyrosol.

Acceptance criteria

Salidroside: NLT 0.6% on the dried basis

Total phenylethanoids: NLT 1.0% on the dried basis

 

CONTAMINANTS

Articles of Botanical Origin <561>, Limits of Elemental Impurities: Meets the requirements

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>, Test for Aflatoxins: Meets the requirements

 

SPECIFIC TESTS

Articles of Botanical Origin <561>, Methods of Analysis, Alcohol-Soluble Extractives, Method 1: NLT 25.0%

Loss on Drying <731>

Sample: 1.0 g of Rhodiola crenulata Root and Rhizome Powder

Analysis: Dry the Sample at 105° for 2 h.

Acceptance criteria: NMT 12.0%

Articles of Botanical Origin <561>, Methods of Analysis,Total Ash: NMT 6.0%

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

 

ADDITIONAL REQUIREMENTS

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

• Labeling: The label states the Latin binomial following the official name of the plant contained in the article.

USP Reference Standards <11>

USP Salidroside RS

USP Rosavin RS

 

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Other Versions

Final Authorized Version 1.0
Proposed For Development Version 0.1