Patents for new chemical entities and small molecules
Produced in partnership with Rouse Legal
Patents for new chemical entities and small molecules

The following IP guidance note Produced in partnership with Rouse Legal provides comprehensive and up to date legal information covering:

  • Patents for new chemical entities and small molecules
  • Compound protection
  • Selection inventions
  • Enantiomers
  • Salts
  • Polymorphs
  • Patentability of small molecules or NCEs

Compound protection

Protection is available for a novel compound or New Chemical Entity (NCE). Such compounds may be claimed individually, but they are more usually claimed in what is known as a Markush claim. These are claimed as a genus, with claims to the NCE phrased as ‘compounds of formula (I),’ where formula (I) describes the chemical structure of the compounds claimed.

Within the field of small molecule patenting here are also several specific niche classes of compound patenting:

Selection inventions

It is possible to gain protection for a smaller genus despite the disclosure of a larger earlier genus. The disclosure of a genus in one patent will not necessarily destroy the novelty of a species falling within that genus. An individual compound that has not been specifically disclosed may be separately patentable. Further a subset of compounds may be novel if not disclosed in the earlier patent (T12/81). Novelty is often imparted to a new grouping by selection from two lists.

A genus is often described as having a common core, then a number of substituents attached to the core, each of which is known as a moiety; all the moieties that each substituent could be are listed. For a genus described as a core with two substituents, R1 and R2, attached to it, a novel selection