This article was taken from the September 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.
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:A Healthy, Wealthy, Sustainable World (Royal Society of Chemistry).
INGREDIENTS •Talc
•Povidone
•Sucrose
•Glucose
•Spearmint flavour
•Calcium carbonate
•Sodium saccharin
•Magnesium stearate
•Heavy magnesium carbonate
TALC
Added to give the tablet a smooth feel in the mouth. Talc is the main ingredient of baby powder, and it is widely used as filler for plastic. It is also the basis of white pottery glazes.
POVIDONE
AKA polyvinyl-pyrrolidone or PVP, this water-soluble polymer holds the other ingredients together. PVP is the adhesive in Pritt and on lick-to-seal envelopes.
SUCROSE
Two simple carbohydrates -- glucose and fructose -- bonded together make sucrose or sugar. Here it is added as a bulking agent, dispersant and sweetener.
GLUCOSE
Derived from the Greek word glukus (meaning "sweet"), C6H12O6 is present in Rennies as a bulking agent. In humans, glucose is the primary source of energy for the brain.
SPEARMINT FLAVOUR
C2H14O is produced by the plantMentha spicata. This is the right-handed form of the molecule. The left-handed form has the flavour of caraway seeds.
CALCIUM CARBONATE
AKA limestone, this neutralises excess stomach acid. Mainly used for making cement, it is also a component of paints, tile adhesives, erasers and PVC.
SODIUM SACCHARIN
An intense artificial sweetener used for more than a century, it was accused (falsely) in the 70s and 80s of increasing risk of bladder cancer.
MAGNESIUM STEARATE
The magnesium salt of stearic acid, a long-chain fatty acid. Here it acts as an excipient, helping the tablet to disintegrate when moistened by saliva.
HEAVY MAGNESIUM CARBONATE
This is a mixture of magnesium carbonate and magnesium hydroxide.
Both chemicals are effective at neutralising acid.
This article was originally published by WIRED UK
