In April 2015, FSANZ conducted an analytical survey of the levels of scheduled pharmaceuticals in weight loss products available in Australia. The survey was conducted in response to a national food incident and a number of international reports showing detectable levels of scheduled pharmaceuticals in foods and supplements intended to promote weight loss.
In October 2010, the New South Wales Food Authority (NSWFA) activated the National Food Incident Response Protocol (NRIP) after the prescription-only medicine sibutramine was detected in imported foods and beverages labelled as ‘slimming foods’ from China and Hong Kong. As a result of the incident, an emergency risk profile was developed which concluded that the presence of sibutramine in food and beverage products exposed vulnerable consumers to a range of side effects and adverse events.
Subsequently, it was agreed that a desktop research exercise should be conducted to determine the breadth of foods and beverages on the Australian and international market intended to promote weight loss, and the types of pharmaceuticals with links to weight loss products, or with weight loss properties. The exercise identified a number of claims and reports both in Australia and internationally of pharmaceuticals in weight loss products, either in foods or beverages, or in capsule and tablet form. Sibutramine and phenolphthalein were the most commonly identified pharmaceutical ingredients.
The desktop research exercise was followed by an analytical survey. The survey results will help build the evidence base to support the Implementation Subcommittee for Food Regulation activity on sports food compliance.
A total of 36 products consisting of powders (25 products), pre-mixed drinks (7 products) and bars (4 products) were purchased from supermarkets, pharmacies and sports stores in the Australian Capital Territory (ACT) in April 2015. These products were a representative sample of available products on the market in this category at these outlets.
Regional sampling was not considered necessary as these foods are national foods available throughout Australia and no regional variability in food composition is anticipated.
Method of analysis
FSANZ collected the samples and transported them to the Therapeutic Goods Administration (TGA) for analysis using a drug screen which analyses the levels of approximately 500 pharmaceutical compounds and their analogues. Products were shelf-stable so specific precautions were not required for transporting the samples.
The primary technique used for screening was ultra-high performance liquid chromatography (UPLC) with photo diode array (PDA) detection. Samples were eluted using reverse phase chromatography with an acetonitrile / phosphate buffer gradient. The UV spectra and retention time were matched against a library with defined matching parameters. Samples were extracted using methanol or a mixture of methanol and water as appropriate.
Library matches were confirmed by comparison of retention time and UV spectra with a reference material and the identification was confirmed using a second technique such as gas chromatography mass spectrometry, or liquid chromatography mass spectrometry.
No pharmaceutical products were detected in 34 of the 36 products.
Two products contained oxedrine (also known as synephrine) at levels which would result in doses of 13 and 39 mg, respectively, when taken according to the serving recommendations listed on the product labels.
Oxedrine is scheduled S4 (prescription-only medicines) for preparations labelled with a recommended daily dose greater than 30 mg. In New Zealand, oxedrine is also prescription-only for medicines containing more than 30 mg per recommended daily dose.
Oxedrine also occurs naturally in bitter orange and other citrus species such as Citrus sinensis (sweet orange) and Citrus limon (lemon). They naturally contain oxedrine at levels up to 0.2% in the fruit. The labels on both products listed bitter orange (Citrus aurantium) or bitter orange extract as ingredients.
Risk assessment of oxedrine in weight loss products
FSANZ has conducted a detailed risk assessment on the affected products and concluded that there are no public health and safety concerns associated with estimated exposure levels, when used according to label instructions. Additional dietary exposure to oxedrine in citrus fruits and other products such as jams and juices does not alter the outcomes of the assessment.