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Compositional guideline: Rhodiola rosea dried root (powdered) extract

21 December 2012

Name of the ingredient

Rhodiola rosea L (AHN)

Definition of the ingredient

The ingredient is obtained by aqueous or hydroethanolic (with up to 70% ethanol v/v) extraction of the powdered dried root (rhizome) of R. rosea L only, and not from the root of any of the related species, such as R. crenulata (Hook. f. & Thomson) H. Ohba and R. sacra (Prain ex Raym.-Hamet) S.H. Fu. The typical native extraction ratio range is 6–10:1 for aqueous extraction and 3–5:1 for hydroethanolic extraction.

Table 1. Ingredient specific requirements
Test Method reference Acceptance criteria
Description
Appearance Visual Brown, non-crystalline powder
Odour Organoleptic Rose-like
Characteristics
Loss on drying BP (Appendix IX D) Not more than 5%
Identification
Chemical fingerprint1 HPLC Complies with authenticated reference material
Assay
Phenylpropanoids2 HPLC 3.0-5.0%
Rosavin3 HPLC 1.5-3.5%
Salidroside4 HPLC 1.0-3.0%

Notes

  1. Test must be validated and capable of discriminating between R. rosea and related species especially R. crenulata and R. sacra. The suggested method is that by Ganzera et al. (2001) Chemical and Pharmaceutical Bulletin 49(4): 465-467. The HPLC profile should be compared against the 'fingerprint' of a genuine standard R. rosea extract, to not only confirm identity but also to determine if any additional peaks are those of potential contaminants. If the comparator 'fingerprint' is not available, the identity of peaks cannot be determined simply based on their retention time. In order to confirm the identity of each peak, peaks should be collected and specific characterisation performed (e.g. GC-MS, NMR or IR spectrum).
  2. The term "phenylpropanoids of R. rosea" comprises the sum of the compounds rosavin, rosarin and rosin.
    • Rosin = 3-phenyl-2-propeny1-O-β-d-glucopyranoside
    • Rosavin = 3-phenyl-2-propeny1-O-(6'-O-α-l-arabinopyranosyl)-β-d-glucopyranoside
    • Rosarin = 3-phenyl-2-propeny1-O-(6'-O-α-l-arabinofuranosyl)-β-d-glucopyranoside.
  3. The term "rosavin" refers specifically to 3-phenyl-2-propeny1-O-(6'-O-α-l-arabinopyranosyl)-β-d-glucopyranoside. The test must be capable of discriminating this compound separately from other phenylpropanoids.
  4. A salidroside content in excess of the phenylpropanoid content is anomalous and may suggest that a preparation is not pure R. rosea extract.
Table 2. Incidental constituents
Test Method reference Acceptance criteria
Residual solvents
Residual solvents BP (Appendix VIII L) Complies
Incidental metals and non-metals
Heavy metals (as lead) BP (Appendix VII) Not more than 10 ppm
Pesticide residues and environmental contaminants (including agricultural and veterinary substances)
Pesticide residues BP (Appendix  XI L) Complies
Microbiology
While substance manufacturers are encouraged to include limits for objectionable microorganisms, it is the product into which those substances are formulated that is subject to a legally binding set of criteria. The Therapeutic Goods Order No. 77 'Microbiological Standards for Medicines' mandates that any finished product that contains the ingredient, alone or in combination with other ingredients, must comply with the microbial acceptance criteria set by Clause 9 of the Order.

Key to abbreviations

BP = British Pharmacopoeia

HPLC = High-pressure liquid chromatography