In this case, which was decided on August 1, 2003, the Federal Circuit again addressed the question of anticipation by virtue of what was inherent in the prior art. After describing the old doctrine of excusing accidental anticipation as set out in Tilghman v. Proctor as being applicable to “accidental, unwitting and unappreciated” anticipation, the court pointed out that failure to recognize that something had been produced previously does not avoid anticipation if that something was clearly produced. In the case before it, the claim was to a metabolite of the antihistamine loratadine (Claritin). Applying the principle that if something would be an infringement after grant, it is an anticipation if it occurs before grant and finding that the metabolite was formed under normal conditions in readily detectable quantities, the Federal Circuit held that the prior production of the metabolite in patients taking loratadine was an anticipation of the claim to the metabolite per se. However, the court went on to state that its reasoning was not intended to preclude the grant of claims to metabolites of known drugs. What mattered was that such metabolites were claimed properly. For example, had the claims been directed to a pure or isolated form of the metabolite, or directed to a pharmaceutical composition containing it, there would have been no anticipation.