Researching drugs is an expensive business and from a commercial point of view, it has to be worth the time and expense to develop new medications or otherwise risk any progress in this industry grinding to a halt.

It is one thing, however, for a company to market a drug at a price which enables it to cover its costs, but quite another to inflate prices simply because it can.

It will be interesting to see the outcome of Pfizer's appeal - and find out which one of these categories the company falls into.