Aktiebolaget Hässle and another v Triomed (Pty) Ltd  4 All SA 138 (SCA) Division: Supreme Court of Appeal Date: 12 September 2002 Case No: 63/2002 Before: Hefer AP, Harms, Farlam, Navsa and Nugent JJA Sourced by: PR Cronje Summarised by: S.Pillay Parallel Citation: 2003 (1) SA 155 (SCA) . Editor's Summary . Cases Referred to . Judgment .  Patent Patent specification Interpretation of Whether a word or phrase appearing in a patentclaim was intended to be an essential requirement of the invention.  Patent Pharmaceutical preparation Infringement Enquiry Comparison between the article or process, or both, involved in the alleged infringement and the wording of the claim in the patent Language of the claim viewed purposively Each word viewed in the context of the invention as a whole to determine the essence of the invention.  Words and phrases "excipients" and "compounds" Viewed purposively Not considered an essential element Chemical composition was immaterial Words were intended to refer to a quantity of excipient or compound, rather than excipients or compounds of more than one kind. Editor's Summary The First Appellant was the patentee of a pharmaceutical preparation and the Second Appellant was licenced to use the patent no. 87/2378 ("the patent"). The Respondent imported and distributed a similar drug called, Ulzec, which the First Appellant alleged infringed its patent. An application to the Commissioner of Patents was dismissed on the sole ground that there was no infringement. Leave to appeal was granted on the basis that the issue for determination on appeal be centred upon that of infringement only. Held The Court examined the chemical composition as well as the purpose of the pharmaceutical preparation. The drug was used in the treatment of gastric and duodenal ulcers and consisted of a substance called omeprazole that helped to inhibit the secretion of gastric acid. The drug was protected by a special substance that created a sub coating, which acted as a barrier between the alkaline core and the enteric coating. It was the composition of this subcoating that was central to the present dispute. Paragraph (b) of claim 1 of the patent specification provided that the alkaline core should consist of "one or more inert reacting subcoating layers comprising tablet excipients . . . alkaline compounds . . ." Relying upon the wording of the specification, the Respondents argued that Ulzec was subcoated with a single Page 139 of  4 All SA 138 (SCA) compound. From a reading of claim 1, it was clear that an important element of the patent was that the subcoating layer should consist of one or more excipients or compounds. The Court held that the interpretation of the actual wording of the patent specification was vital to the dispute. This involved a comparison between the article itself and the wording in the claim specification, in order to ascertain the essence of the claim. The language of the claim had to be construed purposively, by examining the words in the context of the patent as a whole and not in isolation. The Court noted that a patent specification was a statement by the patentee indicating the subject matter of the relevant invention, together with a description of its essential features. The wording of the specification was important to determine whether the patentee had intended that a particular word or phrase be an essential requirement of the invention. Applying these legal principles, the Court found that on a literal construction of the words in paragraph (b) of claim 1, the words "excipients" and "compounds" suggested that there had to be at least two different excipients or compounds. However, viewed in the context of the specification as a whole, the Court held that it was doubtful whether this was the patentee's intention. The reason for this was that it was clear that what was important to the patentee was the function of the subcoating layer; namely, that it formed a protective barrier, rather than its chemical composition. In this instance, the chemical composition was immaterial. The Court was of the opinion that were it important, this would have been specified in the claim. The words in the claim were intended to refer merely to a quantity of excipient or compound rather than to excipients or compounds of more than one kind. This conclusion was strengthened once the Court examined the title and body of the specification. There was nothing herein to suggest that the subcoating layer should consist of more than one excipient or compound. Accordingly, it was held that in the circumstances the Respondent's product infringed the First Appellant's patent. The appeal was upheld with costs.