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Compositional guideline: Conifer phytosterol complex

19 April 2011

Name of the ingredient

Conifer phytosterol complex (AAN)

Definition of the ingredient

Conifer phytosterol complex is a by-product of the wood pulping process used for coniferous trees. There are four main steps in the production of conifer phytosterol complex: (i) alkaline digestion of wood chips to produce tall oil soap; (ii) a solvent extraction process to yield an organic phase; (iii) complexation-washing process of the organic extract to produce the crude sterol mixture; and, (iv) crystallisation of purified sterols from the crude sterol mixture. The bulk anhydrous substance meets the requirements shown in the following table.

Table 1. Ingredient specific requirements
Test Method reference Acceptance criteria
Appearance Visual White to off-white crystalline, waxy powder, free from foreign matter
Odour Organoleptic None or slight chemical odour
Residue on ignition USP <281> ≤ 0.1%
Loss on drying Weight loss after 2 h at 96°C under vacuum ≤ 5%
GC Chemical profile of major components comply with authenticated reference material
Phytosterol content GC ≥ 95%
Sitosterol GC 36 - 79%*
Sitostanol (Stigmastanol) GC 6 - 34%*
Campesterol GC 4 - 25%*
Campestanol (Ergostanol) GC 2 - 12%*
Related substances (C15-C25 aliphatic alcohols) GC ≤ 0.5%*

* % w/w on an 'anhydrous' basis

Table 2. Incidental constituents
Test Method reference Acceptance criteria
Solvent residues
Solvents USP <467> < 0.5%
Incidental metals and non-metals
Total heavy metals US EPA method 200.15 (ICP/AES) ≤ 10 ppm
Lead US EPA method 7000A (Graphite furnace AAS) ≤ 0.25 ppm
Arsenic US EPA method 200.15 (ICP/AES) ≤ 5 ppm
Cadmium US EPA method 200.15 (ICP/AES) ≤ 1 ppm
Mercury US EPA method 245.1 (CVAA) ≤ 1 ppm
Pesticide residues and environmental contaminants
Pesticide residues Ph Eur 2.8.13 Complies
Total aerobic count Sponsor's method ≤ 104 CFU/g
Combined moulds & yeasts Sponsor's method ≤ 100 CFU/g
Coliforms Sponsor's method Negative
E. coli Sponsor's method Negative
Salmonella Sponsor's method Negative
While specifications for this substance include limits for objectionable microorganisms, it is the product into which the substance is 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 which contains the ingredient, alone or in combination, must comply with the microbial acceptance criteria set by Clause 9 of the Order.

Key to abbreviations

BP = British Pharmacopoeia

CFU = Colony forming units

CVAA = Cold vapour atomic absorption spectrometry

GC = Gas Chromatography

ICP/AES = Inductively coupled plasma-Atomic emission spectrometry

Ph Eur = European Pharmacopoeia

US EPA = United States Environmental Protection Agency

USP = United States Pharmacopoeia