On Friday I was at a meeting in which most of the speakers were scientists working in the pharmaceutical industry. It was at the Royal Society of Chemistry’s London office which is just off Piccadilly in London. This was handy as there is an iron law of scientific meetings: The coffee is terrible. At lunch I popped out and grabbed a good cappuccino on Piccadilly; this kept me going in the afternoon session.

The pharmaceutical industry is a big industry that employs a lot of scientists. Pharmaceutical companies develop new drugs, and this can take 10 years, and can cost £100 million or more. The drugs are patented, which means that for the period of the patent only the drug company who developed and patented it, can make and sell it. This is a big deal. For example, when under patent, Glaxo Wellcome’s drug against stomach ulcers, Zantac made £1 billion + a year in sales. Over a 10 year patent that’s over £10 billion.

That is a lot of money. But when the patent runs out any company can make and sell it, and so competition will drive down the cost. This is upsetting for a drug company. Perhaps the most interesting talk yesterday was on the interesting collision of science and law that can then happen.

You may think that you can only patent a drug molecule once, and that is it. After all you can only patent novel inventions or products, and surely once you have patented the Zantac molecule once you can’t do it again. Or can you?

In some circumstances you can, and the reason is something I mentioned in an earlier post: the fact that many substances form not one but several different types of crystal. The example given in A-level chemistry of this is carbon, which forms both graphite and diamond.

Glaxo Wellcome initially patented crystal from I of Zantac, and sold it. Then several years later, they patented the same molecule Zantac but in a different crystal form, crystal form II. Handy. As I understand it from yesterday’s talk, this can only be done if the company can show that the new form of the crystal, here form II, is better than the old form.

This is where scientists come in. How effective a drug is depends on the crystal form in the tablets because different crystals of the same molecule will differ in solubility. One crystal may be too soluble and so dissolve very rapidly, giving the body a sudden sharp spike in the drug, whereas another may be too insoluble, and so dissolve very slowly. Then the drug may not make it into the bloodstream – which of course is hopeless.

So scientists work to get the drug into a useful crystal that dissolves at the right rate in the body. Then sometimes they go back and do it all again, and get a second patent.