This article was taken from the December 2011 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.
Give Arthritis a pasting -- shrimp extract and wallpaper paste join forces to keep your joints supple.
Each month Wired's chemist Dr John Emsley deconstructs an everyday product. He is author of 110 research papers and ten books, including his most recent: Nature's Building Blocks, 2nd edition (OUP). - Glucosamine sulphate dipotassium chloride (shellfish)
Hydroxypropyl methyl cellulose
Polyvinylpyrrolidone
Ascorbic acid
Glucose
Cellulose
Stearic acid
Magnesium stearate
Talc
Glucosamine sulphate dipotassium chloride
The active ingredient, with the glucosamine component thought to protect joints by replenishing its natural glucosamine. It is produced from shrimp shells.
Hydroxypropyl methyl cellulose
A modified form of cellulose with methyl and hydroxypropyl groups attached, which convert it into a viscous fluid.
Normally it is used to thicken foods and in household products.
<span class="s1">Polyvinyl-pyrrolidone
Provides a water-soluble polymer film which prevents the tablets from drying out. PVP is also used in toothpastes and is the adhesive in envelopes that need to be licked before being sealed.
Ascorbic acid
Involved in many functions within the human body, in the case of protecting the joints, it acts to prevent free-radical damage as well as being essential for tissue repair. It also has antioxidant properties.
Glucose
Chemical formula c6h<span class="s2">12o6 is the simplest and most abundant carbohydrate produced by plants, which convert it to the natural polymers starch and cellulose. Here, it acts as a safe bulking agent.
Cellulose AKA E460, this consists of long chains of linked glucose molecules. Here it helps the tablet disintegrate when it reaches the stomach. It is also used to thicken foods, and is the main ingredient in wallpaper paste.
Stearic acid
A saturated fatty acid used to make candles, cosmetics, soap and to soften plastics and rubber. Magnesium stearate is its magnesium salt and together they are used as an anti-caking agent and lubricant.
Talc One of the softest minerals known, it finds use as talcum powder in cosmetics and as a filler in paper manufacture. Here it acts as an excipient, helping the tablet to break up easily once it has reached the stomach.
This article was originally published by WIRED UK
