Polymorphism and patents

A brief introduction to patents is followed by a discussion of the two main issues of patents on (pharmaceutical) polymorphs from the scientific perspective: novelty and obviousness, with an emphasis on the latter. The issues, decisions, and ramifications of six landmark patent litigations involving solid forms are described. These involved the following drugs: cefadroxil, terazosin hydrochloride, ranitidine hydrochloride, paroxetine hydrochloride, armodafinil, and tapentadol hydrochloride. The chapter closes with a description of the litigation on the synthetic sweetener aspartame which involved an issue of habit (shape) rather than the form (crystal structure).