Sudarshan v Clariant [2012] EWHC 1569 (Ch)

 Martin Howe QC and Henry Ward appeared for the claimant in this action for invalidation of a patent or declaration of non-infringement, and threats. The patent was for what was said to be a new crystal modification (polymorph) of a pigment which had been discovered and previously patented by Clariant. John Baldwin QC (sitting as a deputy judge of the Chancery Division) held that the patent was invalid because following the prior art patent would result in the production of the polymorph at the "wet cake" stage and the results of Sudarshan’s own production processes indicated that a substantial amount of it would remain through the drying and finishing stages. Further, Clariant’s proposed amendments to the claims would result in added matter.

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