Anticipate This!™ | Patent and Trademark Law Blog

Ortho-McNeil Pharmaceutical, Inc. v. Caraco Pharmaceutical Laboratories, Ltd.

Posted in Opinion Commentary by Jake Ward on January 22, 2007

Intrinsic Evidence Pointing to a Criticality of a Claimed Ratio Used to Construe the Term “About.” 

(Fed. Cir. 2007, 06-1102)


Caraco filed an ANDA with the intent to make and sell a pharmaceutical composition containing tramadol and acetaminophen with an average weight ratio of tramadol to acetaminophen of 1:8.67, and no less than a ratio of 1:7.5.  In response,  Ortho filed suit and argued infringement of Claim 6 of Ortho’s U.S. Pat. No. 5,336,691 (“the ’691 patent”).  The district court (E.D. Mich.) granted Caraco’s motion for summary judgement and Ortho appealed to the CAFC.

Claim 6 of the ‘691 patent recites, effectively:

“[A pharmaceutical composition comprising a tramadol material and acetaminophen], wherein the ratio of the tramadol material to acetaminophen is a weight ratio of about 1:5.”

The district court construed the “about 1:5” limitation of claim 6 to mean “approximately 1:5, encompassing a range of ratios no greater than 1:3.6 to 1:7.1.”  In reaching this construction, the court relied on intrinsic evidence (specification), extrinisic evidence (expert testimony), and evidence related to Ortho’s application to reissue the ‘691 patent (Claim 6 rewritten to use the transitional phrase “consisting essentially of” instead of “comprising”).   

Under its construction, the district court concluded that Caraco’s ANDA-defined product did not literally infringe the ’691 patent.  Under the doctrine of claim vitiation, the court further concluded that finding infringement by Caraco’s formulation would render meaningless the “about 1:5” limitation, and thus rejected Ortho’s DOE arguments.  The CAFC agrees.

On appeal, the central issue was whether the district court properly construed the claim phrase “about 1:5, ” and particularly the term “about?”  The CAFC reiterated that the word “about” does not have a universal meaning in patent claims . . . the meaning depends upon the technological facts of the particular case.  Additionally, the intrinsic evidence in this case points to a meaning for the term “about 1:5” that is narrow because the 1:5 weight ratio was distinctly claimed and distinguished from other broader weight ratio ranges in the claims patent.  Other intrinsic evidence supporting the narrow construction includes paragraphs in the specification and the described experiments.  The intrinsic evidence points to the desirability, and thus the criticality, of the 1:5 ratio versus other ratios.

The product described by Caraco’s ANDA application did not literally infringe.  Also, because the intrinsic evidence points to the desirability, and thus the criticality, of the 1:5 ratio versus other ratios, Ortho could not argue that the parameter is broad enough to encompass, through the DOE, ratios outside of the confidence intervals expressly identified in the patent. 


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