Merial v Cipla Vet (Pty) Ltd

Merial, a French company, is the patentee of South African Patent No. 96/8057 entitled "Anti-parasitic composition for the treatment and protection of pets". Merial Limited (UK) and Merial South Africa (Pty) Ltd are licensees. The patent concerns a "spot-on" formulation containing fipronil used to treat and protect domestic animals (cats and dogs) against parasites such as fleas, ticks and galls. The invention specifically relates to a composition that minimizes crystallization on the animal's coat. Cipla Vet (Pty) Ltd has since 2008 manufactured, used, sold and imported a competing product called "Fiprotec" which the appellants alleged infringes claims 1, 2, 3, 7 to 15 and 18 to 20 of the patent. The composition in claim 1 consists of four constituents: (a) fipronil; (b) a crystallization inhibitor which must satisfy a specific test (integer b test); (c) an organic solvent with defined properties; and (d) an organic co-solvent which is a drying promoter. Fiprotec contains: 9.7% fipronil; 50% DGME; 27.7% propylene glycol (PG); 1.40% polyvinylpyrrolidone (PVP); 1% polysorbate 80 (Tween 80); 10% ethanol; and antioxidants. All these ingredients are mentioned in the patent specification, though sometimes for alternate functions. Cipla denied infringement and challenged the validity of the patent on grounds of lack of clarity, insufficiency and inutility, but did not counterclaim for revocation. The Court of the Commissioner of Patents (Murphy J) held that the appellants failed to prove infringement, primarily because expert tests on the crystallization inhibitor used different sources of fipronil (Merial-supplied versus Cipla's GSP Crop Science-sourced fipronil). However, the Commissioner dismissed Cipla's validity challenges.

• Whether the patent lacks clarity due to the dual and interchangeable functionalities of constituent ingredients in the formulation
• Whether the appellants proved that Cipla's Fiprotec product infringes claims 1, 2, 3, 7 to 15 and 18 to 20 of the patent
• Whether the integer b) crystallization inhibitor test was properly conducted and whether Fiprotec satisfies that test
• Whether ethanol in Fiprotec serves as the organic co-solvent as required by integer d) of claim 1
• Whether the mixture of PVP and Tween 80 in Fiprotec operates as a crystallization inhibitor within the meaning of integer b)
• The standard of clarity required for patent claims and the test for determining lack of clarity
• Whether it was permissible to use Merial-supplied ingredients rather than Cipla's actual Fiprotec ingredients in conducting the integer b) test

1. The appeal is upheld with costs including the costs of two counsel. 2. The order of the court below is set aside and substituted as follows: (a) The defendant (Cipla) is interdicted and restrained from infringing claims 1, 2, 3, 7 to 15 and 18 to 20 of the patent. (b) The defendant is ordered to deliver up to the plaintiffs all infringing Fiprotec products in its possession or under its control. (c) An inquiry is ordered in relation to the damages suffered by the plaintiffs as a consequence of the infringement of the patent by the defendant alternatively an inquiry into the reasonable royalty to which the plaintiffs are entitled. (d) In the event of the parties being unable to reach an agreement as to the further pleadings to be filed, discovery, inspection or other matters of procedure relating to the inquiry, an order authorising any one of the parties to make application to the court for directions in regard thereto. (e) Each of the claims referred to in para 1 above of South African Patent Number 1996/8057 is certified as being valid in terms of section 74 of the Patents Act 57 of 1978. (f) The defendant is ordered to pay the plaintiffs' costs of suit, including the costs of two counsel and the qualifying fees of the plaintiffs' expert witnesses.

1. A patent claim is not unclear merely because constituent ingredients in a formulation may serve dual or interchangeable functions, provided that a skilled addressee can determine which function a particular ingredient serves in a given formulation through systematic scientific methods. 2. Patent specifications must be construed by "a mind willing to understand, not by a mind desirous of misunderstanding." Courts will interpret patents as a process of construction, not deconstruction. 3. The standard for clarity of patent claims is "reasonable certainty," not absolute certainty. Hypothetical or "mythical" formulations that do not reflect how skilled persons would actually work in practice will not render a patent unclear. 4. In pharmaceutical formulation patents where ingredients may be selected from lists based on functional requirements, the patent is sufficiently clear if a skilled formulator can understand how to select appropriate ingredients based on the functions they need to serve in the composition. 5. In proving patent infringement, it is permissible to conduct tests using equivalent ingredients from different suppliers, provided there is no credible evidence that the source of ingredients would materially affect the outcome. Mere speculation about possible differences is insufficient to defeat proof of infringement. 6. Where expert evidence is central to issues of patent validity and infringement, courts will prefer the evidence of experts with direct expertise in the field of the invention over experts with narrower or tangential expertise. 7. The reliability and scientific rigor with which tests are conducted will be carefully scrutinized when such tests are determinative of infringement, and carelessly conducted tests will be rejected even if they purport to use the actual ingredients of the allegedly infringing product.

1. The court noted that Cipla did not counterclaim for revocation of the patent as it was entitled to under section 65(4) of the Patents Act, but instead raised validity as a defense. While this was procedurally permissible, the observation highlights the different procedural routes available to defendants in patent infringement actions. 2. The court observed that the challenge based on uncertainty regarding observation "by the naked eye" of crystals in the integer b) test was "with good reason, not persisted in," noting that Professor Barbour conceded he had no difficulty measuring crystallization with ordinary vision (which in appropriate circumstances could be corrected by spectacles) and that environmental factors could be controlled. 3. The court commented that evidence from non-expert witness Mr Swiegers regarding crystals appearing on dogs' coats after Fiprotec application was properly disregarded by the trial court, as claim 1 did not specify any degree of visibility of crystals on an animal's coat. This evidence was not relied upon on appeal. 4. The court noted that the lack of clarity attack "evolved somewhat during evidence and argument" beyond what was pleaded, and that the expanded attack more properly resided under the ground of insufficiency rather than clarity. However, because the issue was explored extensively in evidence, the court considered it on appeal. 5. Murphy J's finding that Dr Witchey's use of a weighing cabinet to conduct the integer b) test was legitimate and did not artificially inhibit evaporation was accepted by the SCA. The court noted this was to avoid artificial enhancement of evaporation that would occur if the slide were exposed to air handling systems in an open laboratory. 6. The court referenced pharmaceutical formulation patents in other cases (Pharma Dynamics v Bayer Pharma AG) to illustrate that patents involving selection of ingredients from lists for pharmaceutical formulations are not uncommon and not inherently unclear. 7. The court cited with approval the principle from Integrated Mining Systems v Chamber of Mines that courts will not find insufficiency (and by analogy, lack of clarity) simply because exceptional cases or unlikely materials might come within the words of the specification and will not work. 8. The court noted the statutory obligation under the Patents Act for a patentee to state in the claims "clearly and distinctly" what the invention is, citing Power Steel Construction, while also noting that the required standard is reasonable certainty, not perfection, citing Letraset Ltd v Helios Ltd and De Beers Industrial Diamond Division v General Electric Company for the proposition that "absolutism does not perch happily upon the banner of our law."

This case is significant in South African patent law for several reasons: 1. **Clarity of Patent Claims**: It establishes that patent claims involving complex chemical formulations with multiple ingredients serving potentially dual functions will not be found to lack clarity where a skilled addressee can understand how to select and combine ingredients based on their required functions. The court emphasized that "reasonable certainty" rather than absolute certainty is the required standard. 2. **Construction vs Deconstruction**: The judgment reinforces the principle from Ausplow that "patents are about construction and not deconstruction of the text" and that "a patent must be read by a mind willing to understand, not by a mind desirous of misunderstanding." Hypothetical or contrived scenarios that do not reflect how skilled persons would actually work will not invalidate a patent for lack of clarity. 3. **Pharmaceutical Formulations**: The case provides important guidance on how courts will approach patents for pharmaceutical formulations where ingredients may be selected from lists and may serve multiple functions. It confirms that such patents are not inherently unclear. 4. **Expert Evidence in Patent Cases**: The judgment illustrates the critical importance of relevant expertise in patent litigation. The court preferred the evidence of a formulation chemist (Dr Witchey) who had direct expertise in the field of the invention over a crystallographer (Professor Barbour) whose expertise was limited to one aspect of the patent. 5. **Proof of Infringement**: The case clarifies that in proving infringement through testing, it is not fatal that the plaintiff uses equivalent ingredients from different suppliers rather than the exact ingredients of the allegedly infringing product, provided there is no evidence that the source of ingredients materially affects the results. Speculation about possible differences is insufficient to defeat a claim of infringement. 6. **Scientific Rigor in Testing**: The judgment emphasizes that courts will scrutinize the reliability and care with which scientific tests are conducted when such tests are central to proving or disproving infringement. The case reinforces that challenges to patent validity must be substantive rather than based on theoretical or contrived difficulties, and that patents will be construed practically from the perspective of the skilled addressee.