Study shows many medicines contain unlabelled animal products

People in Hong Kong with dietary restrictions could be unwittingly ingesting animal ingredients, including those banned by religious laws, in the form of everyday medicines.

A new British study found that undeclared products of animal provenance are present in numerous common medications taken globally - and, like Britain, Hong Kong has no official requirements when it comes to the labelling of ingredients of animal origin.

There are some cases in which medicines themselves are sourced directly from animals - blood thinner Heparin can come from pigs, for example, while some popular brands of oestrogen are made from pregnant mare's urine.

But more frequently, problem ingredients only crop up in the administered form of a drug, such as a tablet, often in the shape of fillers, binders and capsules. The three most common are lactose, used mainly as a filler, which comes from cow's milk, and is traditionally extracted using rennet from calves' stomachs; gelatin, used to make capsules, and traditionally made from the skin and bones of cows and pigs; and magnesium stearate, used as a lubricant in tablet manufacturing and to make tablets soluble, and traditionally made from rendered animal fat.

According to an article ("Suitability of Common Drugs for Patients Who Avoid Animal Products") published recently on the website of the medical journal BMJ, these three ingredients in particular are present in 74 of 100 of the most commonly used medications in Britain, including painkillers such as aspirin and paracetamol, and common medications to deal with high blood pressure, heart disease and stomach conditions.

Co-author of the article Kinesh Patel, research fellow in the Wolfson Unit for Endoscopy at St Mark's Hospital in Harrow, London, says the most popular drugs and their ingredients are very similar in Hong Kong; many large drug brands are global, and companies naturally prefer to make a single version of a drug and distribute it globally rather than catering for local markets with specific versions.

The biggest issue, Patel found in his research, conducted with Kate Tatham, research fellow in the Section of Anaesthetics, Pain Medicine and Intensive Care at Imperial College, Chelsea and Westminster Hospital in London, is that the possible animal origin of ingredients is rarely marked on drug packaging or information leaflets; and even when potentially problematic ingredients are listed, crucial information about how they were obtained often isn't.