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Compositional guideline: Calcium L-threonate

27 February 2014

Name of the ingredient

Calcium L-threonate (AAN)

Definition of the ingredient

(2R,3S)-2,3,4-trihydroxybutyric acid hemicalcium salt; L-Threonic acid calcium salt

Molecular formula: CaC8H14O10

Molecular mass: 310.27

CAS Number: 70753-61-6

Table 1: Ingredient specific requirements
Test Method reference Acceptance criteria
Description
Appearance Visual White powder
Characteristics
Solubility BP (General notice) Soluble in water
Appearance of solution (5% aqueous solution) Ph Eur method 2.2.1 and 2.2.2, Method II Clear and colourless
pH (5% aqueous solution) Ph Eur method 2.2.3 6.0 - 8.0
Specific optical rotation (5% aqueous solution) Ph Eur method 2.2.7 +13.0° to +14.3°
Loss on drying Ph Eur method 2.2.32 Not more than 1.5% w/w
Identification
Calcium L- threonate

Ph Eur method 2.2.24

(IR)

Complies with authenticated reference standard
Threonic acid

Ph Eur method 2.2.24

(IR)

Complies with authenticated reference standard
Calcium

Ph Eur method 2.3.1

(Qualitative reaction and tests)

Positive
Assay
Calcium Ph Eur method 2.5.11 12.7 - 13.2% w/w, on dried basis
Threonic acid Capillary Electrophoresis - Indirect UV detection 85.8 - 88.4% w/w, on dried basis
Table 2: Incidental constituents
Test Method reference Acceptance criteria
Other organic or inorganic impurities or toxins
Residual solvents USP (467) Complies
Carbonates

Ph Eur method 2.3.1

(Qualitative reaction and tests)

Negative
Ascorbic acid HPLC Not more than 0.1% w/w
Incidental metals and non-metals
Heavy metals (as lead) Ph Eur method 2.4.8 Not more than 10 ppm
Iron Ph Eur method 2.4.8 Not more than 100 ppm
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 performance liquid chromatography

IR = Infrared

Ph Eur = European Pharmacopoeia

USP = United States Pharmacopeia

UV = Ultra violet