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Compositional guideline: Quercetin dihydrate

16 August 2013

Name of the ingredient

Quercetin dihydrate (AAN)

Definition of the ingredient


Molecular formula: C15H10O7.2H2O

Molecular mass: 338.2 (302.24 for anhydrous)

CAS Number: 6151-25-3

Table 1: Ingredient specific requirements
Test Method reference Acceptance criteria
Appearance Visual Yellow crystals or yellowish powder
Solubility BP (General notice) Practically insoluble in water, slightly soluble in absolute alcohol, soluble in aqueous solutions of alkali
Water (determined on 0.100g) BP (Appendix IX C, method 1) 9.0%-12.0%
Perform either the IR test or both TLC and HPLC tests as below
IR BP (Appendix II A) Spectrum matches that of the authenticated reference material
TLC BP (As prescribed in the monograph for Ginkgo Leaf); Ph Eur monograph 1828

The principal spot in the chromatogram obtained with the test solution corresponds to that obtained with the solution of the reference material

Note: This test must be done in conjunction with HPLC

HPLC BP (Appendix III D) The retention time of the principal peak in the chromatogram of the test solution matches that of the solution of the authenticated reference material
Quercetin HPLC 98.0-102.0% w/w (anhydrous basis)
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
Other organic or inorganic impurities or toxins
Sulfated ash BP (Appendix IX A) Not more than 0.2%


Related substances HPLC Not more than 1.0% for any individual impurity, 2.0% for total impurities
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

IR = Infrared spectrophotometry

TLC = Thin layer chromatography