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Purpose-based Distinction Applies to Process Claims OnlNovember 16, 2006

In Abbott Laboratories and Central Glass Company, Ltd. (‘Abbott’) v. Pharmaceutical Products, Inc. and Baxter healthcare Corp. (‘Baxter’), the Federal Circuit upon second hearing reversed the district court’s judgment that the asserted claims were valid and, such, did not reach questions of infringement or inequitable conduct.At issue was a patent (‘the ‘176 patent’) pertaining to the degradation-preventing combination of water or other ‘Lewis acid inhibitors’ with sevoflurane. The case came before the Federal Circuit the first time when it reviewed the district court’s construction of the phrase ‘amount effective to prevent degradation’ to require at least 131 parts per million (‘ppm’) of water and its consequent summary judgment of non-infringement. The Federal Circuit disagreed with that construction vacating the district court’s summary judgment and remanded. On remand, the district court conducted a bench trial finding that the term ‘to prevent degradation’ had been left unconstrued, and concluded that sevoflurane is degraded if it contains degradants in amounts greater than 300 ppm. Further, the district court concluded that a patent which disclosed a composition of water-saturated sevoflurane (‘the ‘211 patent’) did not anticipate because it was directed at a different purpose than the ‘176 patent. The Federal Circuit noted that the district court found the ‘176 patent valid due to the purpose-based distinction. It found the district court committed legal error in applying the purpose-based distinction to composition claims as were the claims in the instant matter (a mixture of sevoflurane and water); clarifying that the purpose-based distinction only applied to process claims. In reversing the district court, the Federal Circuit found that both the ‘176 and ‘211 patents disclosed methods which help to ensure that sevoflurane will be of high purity at the time it is administered to patents. The Court noted that all that is contributed by the method claims of the ‘176 patent is the recognition of a new property of the prior art process. Thus finding all asserted claims invalid.To read the full text of the decision, log on to

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