5.6.6.6 Issues Specific to Chemical Compositions

Also in this Chapter:

• 5.6.6.1 Overview of the inventive step requirement

• 5.6.6.2 Information against which inventive step is assessed
• 5.6.6.3 Tests for inventive step
• 5.6.6.4 Assessment of inventive step
• 5.6.6.5 Indicators of inventive step

Key Legislation:

Patents Act:

• s7(2), 7(3) Novelty
• s18(1)(b)(ii) Patentable inventions
• s49 Acceptance of patent request: standard patent  
• Schedule 1 Dictionary

Related Chapters​:

• 5.5.2.3 The role of common general knowledge
• 5.6.1.4 Balance of Probabilities Standard
• 5.6.1.5 Application of the Balance of Probabilities in Examination
• 5.6.6.4 Assessment of Inventive Step 

On this page

• Problem in compound per se claims
• Anticipation by generic disclosures
• Optical isomers.

Problem in compound per se claims

Where a claim is directed to compounds per se, the problem addressed by the specification will usually be "to provide compounds suitable for a specific use". The "use" in question could be the biological activity of the compounds or use as intermediates in the synthesis of other compounds (American Home Products Corporation Application [1994] APO 58).​​​​​​​

Anticipation by generic disclosures

​​​​​​​There is no invention in mere verification of a result suggested by the prior art. For example, if the prior art indicates that certain compounds can be made by a particular reaction and suggests that other compounds could also be made by the same process, it is not inventive to verify that result (Sharp & Dohme Inc. v Boots Pure Drug Co. Ltd (1928) 45 RPC 153 at page 192).

Where a compound is within the scope of an earlier generic disclosure in a document, the objection of lack of inventive step should be considered separately to the issue of novelty. If the compounds within the generic disclosure are alleged to solve the problem, then prima facie there will be a lack of inventive step.

A generic structural formula represents all the specific structural formulae encompassed by the generic formula. This can be described as the intellectual content of the generic formula. The compounds that are within the intellectual content of a document are clearly put forward as possessing the same properties as the compounds within the technical content. In the absence of selection or the lack of an enabling disclosure, it is immediately obvious that the compounds of the intellectual content would be expected to have the same properties as the compounds within the technical content and there is no inventive step in merely preparing those compounds in the manner suggested and verifying their properties (Rohm and Haas Co. v Nippon Kayaku Kabushiki Kaisha and Sankyo Co. Ltd (1997) APO 40).

Where the document does not disclose the particular property or use of the compounds that is relevant to the problem, then it probably does not solve the problem (American Home Products Corporation Application [1994] APO 58).

If the particular compounds cannot be prepared by the prior art method or there is no method of preparation given, then there will be an inventive step in preparing the compounds.​​​​​​​

Optical isomers

Where a racemic mixture is known for a specific use and the problem is to find a compound having that property in an enhanced level, or the same property with less side-effects, the question inevitably arises whether one of the isomers in isolation is an obvious solution. It is reasonable to presume that it is common general knowledge that one isomer is often more active than the other, although this is not invariably the case. The single isomer will be an obvious solution if it would have been a matter of routine to prepare the single isomer and test its activity.

If the isomer is prepared by routine separation techniques, the single isomer will be an obvious solution. This is true even if it was not obvious beforehand which of the isomers would be more active (see Rhone-Poulenc Rorer S.A.'s Application [1995] APO 50).