Choline Bitartrate

Choline bitartrate is the L(+)-hydrogen tartrate salt of choline, CAS 87-67-2, molecular formula C9H19NO7, molecular weight 253.25. It is the most widely traded solid choline source for human nutrition, delivering approximately 41 per cent choline by weight (the choline cation contributes 104.17 of the 253.25 molecular weight), so that 1 g of the salt supplies roughly 410 mg of choline and about 2,400 mg of salt is required for 1,000 mg of choline. Choline is an essential nutrient: it is the precursor of phosphatidylcholine and sphingomyelin, which are structural components of cell membranes, the precursor of the neurotransmitter acetylcholine, and, through oxidation to betaine, a source of methyl groups for one-carbon metabolism. Choline bitartrate is affirmed generally recognised as safe in the United States under 21 CFR 182.8250 and is an accepted source of choline in food supplements, fortified foods and infant nutrition. Where choline chloride (about 75 per cent choline) is unsuitable because of its chloride load, corrosivity, deliquescence and pronounced amine odour, the bitartrate salt is the standard alternative for tablets, capsules, flavoured powders and paediatric nutrition. The material offered is a white to off-white crystalline powder, hygroscopic, with a slightly acidic taste; melting range 149-153 degrees C; freely soluble in water, slightly soluble in ethanol and insoluble in ether, chloroform and benzene; a 10 per cent w/v aqueous solution gives a pH of 3.0-4.0. Manufacture proceeds by reacting trimethylamine with ethylene oxide in aqueous solution to form choline base, which is neutralised with natural L(+)-tartaric acid under nitrogen, then concentrated and crystallised - only the natural L(+) isomer of tartaric acid is used. Grades supplied are USP-NF dietary supplement grade (assay not less than 96.5 per cent and not more than 100.5 per cent, as-is basis), FCC food grade (assay not less than 98.0 per cent) and feed grade, with loss on drying not more than 0.5 per cent, lead not more than 2 mg/kg to FCC and heavy metals not more than 10 ppm. Each lot carries a certificate of analysis covering identification, assay by titration, calculated choline content, loss on drying, pH of the 10 per cent solution, residue on ignition, heavy metals by ICP-MS and microbiological limits including total plate count, yeast and mould, E. coli and Salmonella; third-party laboratory reports, allergen, GMO and BSE/TSE declarations, kosher and halal certificates and an MSDS are issued with the shipping documents. Because the salt is markedly hygroscopic it is filled under controlled humidity, sealed in double liners and should be kept below 25 degrees C in the closed original pack, with part-used containers resealed immediately. Direct-compression, granular and free-flowing coated grades for dry premixing are available against specification.