Even if estoppel applies, however, the patentee may demonstrate that the narrowing amendment did not surrender the particular equivalents at issue. Id. at 741. The standard for determining whether particular subject matter was relinquished is an objective one that depends on what a competitor reasonably would conclude from the patent’s prosecution history.

B. Argument-Based Estoppel

Clear assertions made during prosecution in support of patentability, whether or not actually required to secure allowance of the claim, may also create an estoppel. To invoke argument-based estoppel, the prosecution history must evince a clear and unmistakable surrender of subject matter. Thus, the legal standards for amendment-based estoppel and argument-based estoppel differ greatly.

II. Prosecution history estoppel does not bar availability of the doctrine of equivalents in plaintiffs’ action for infringement of the ’974 patent.

The ’974 patent is for a two-layer tablet, with one layer of antihistamine (from the genus of which fexofenadine is one species) and another layer of decongestant. Defendants make only one argument relating to the examiner’s statements in the office action allowing the claims: “[h]aving failed to contest the P.T.O.’s stated reasons for allowance, Plaintiffs have disallowed any broader constructions.” That single sentence contains defendants’ entire argument on this matter. Defendants propose no legal theory to explain why plaintiffs have disallowed any broader constructions.

III. Prosecution history estoppel bars availability of the doctrine of equivalents in plaintiffs’ actions for infringement of the ’942 and ’912 patents.

Both plaintiffs and defendants agree that the written descriptions of the ’942 and ’912 patents are virtually identical, and do not differ materially for the purposes of this summary judgment motion. The two patents will be considered together in this opinion.

The focus of the parties’ dispute is the actual reason for the narrowing amendments. Plaintiffs argue that the applicants made narrowing amendments not for reasons of patentability, but to comply with the examiner’s election/restriction requirements. Defendants argue that the narrowing amendments were made for reasons of patentability.

The prosecution history shows clearly a narrowing amendment made to avoid a rejection under 35 U.S.C. �� 102(b) and 103. Given that the applicant made a narrowing amendment for reasons of patentability, under Festo VIII, this gives rise to the rebuttable presumption that the patentee surrendered the equivalents in question.

Examination of the history of the second application reveals that the applicant did obviously surrender one of the equivalents at issue, sodium starch glycolate. As noted above, this inert ingredient was specified in claims initially made in the second application, but, after those claims were canceled, never appeared in any claims again. This is an umistakable surrender of an equivalent in question, sodium starch glycolate.

The prosecution history does not manifest this same kind of clear surrender of the other inert ingredients at issue. At no point in the entire prosecution history do any claims mention povidone, corn starch, mannitol, crospovidone or powdered cellulose. Nor does the rationale for claim rejection in the first office action make explicit reference to these ingredients or to the topic of inert ingredients.

Defendants did not offer a specific argument-based estoppel analysis, but mixed prosecution arguments with narrowing amendments in one general analysis. In doing so, they overlook that the analyses involve very different legal standards. Given that plaintiffs have failed to rebut the presumption of surrender in the amendment-based estoppel inquiry, the court need not address in detail defendants’ points on argument-based estoppel.

Held: In sum, the prosecution history of the ’942 and ’912 patents shows narrowing amendments made for reasons of patentability. Plaintiffs have failed to rebut the presumption of surrender of the equivalents in question, and are barred from using the doctrine of equivalents in their present actions for infringement of the ’942 and ’912 patents.

IV. Prosecution history estoppel bars availability of the doctrine of equivalents in plaintiffs’ actions for infringement of the ’247 patent.

The prosecution history of the ’247 patent has many similarities to that of the ’942 and ’912 patents, as it began with a common application with broad generic formulation claims and ended with a patent claiming � like the ’942 and ’912 patents � defined formulations of fexofenadine and specific inert ingredients. As with the ’942 and ’912 histories, the parties do not dispute that the ’247 prosecution history shows narrowing amendments.

Plaintiffs argue that the prosecution history of the ’247 patent differs crucially from the histories of the ’942 and ’912 patents in that the ’247 patent resulted from divisional applications of the original applications, while the ’942 patents resulted from continuation applications.

In this case, the applicant filed a series of applications with successively narrower claims in the context of multiple interrelated applications with multiple rejections. Viewing the prosecution history as a whole, the applicant clearly made narrowing amendments to secure the patent. Moreover, the Federal Circuit has considered the prosecution history of related patents and applications broadly. Most important, it has specifically applied Mark I Mktg. Corp. v. R.R. Donnelley & Sons Co., 66 F.3d 285, 292 (Fed. Cir. 1995), cert. denied, 516 U.S. 1115 (1996) (holding held that a series of narrowing applications may form the basis for a finding of surrender of claim coverage), to prosecution histories involving divisional applications. See Desper Prods. v. Qsound Lab., 157 F.3d 1325, 1339 (Fed. Cir. 1998). It has even found estoppel from the prosecution history of one patent to apply to a different patent stemming from the same original application. See Jonsson v. Stanley Works, 903 F.2d 812, 817 (Fed. Cir. 1990). In Elkay Mfg. Co. v. Ebco Mfg. Co., 192 F.3d 973, 980 (Fed. Cir. 1999), the court held that “[w]hen multiple patents derive from the same initial application, the prosecution history regarding a claim limitation in any patent that has issued applies with equal force to subsequently issued patents that contain the same claim limitation.” These cases manifest an approach that considers the prosecution histories of related applications and patents broadly and inclusively, avoiding purely formalistic distinctions such as that between a continuation and a divisional application.

Plaintiffs have failed to rebut the presumption of surrender of the equivalents in question.

The equivalents in question in the action for infringement of the ’247 patent are powdered cellulose, mannitol, crospovidone and povidone. Plaintiffs made no new arguments to rebut the presumption of surrender of the equivalents in question in their action for infringement of the ’247 patent, relying on the arguments made with regard to the ’942 and ’912 patents. The court has considered those arguments above and determined that plaintiffs have failed to rebut the presumption of surrender.

Dedication

As an alternative ground for their summary judgment motion, defendants contend that the subject matter that was disclosed but not claimed in the ’942, ’912, ’974 and ’247 patents is “dedicated to the public” and therefore cannot fall within the scope of equivalency.

Prosecution history estoppel bars plaintiffs from asserting sodium starch glycolate, povidone, mannitol, crospovidone, powdered cellulose and corn starch as equivalents for excipients in the ’912, ’942 and ’247 patents. However, the court will consider defendants’ dedication arguments in full to determine the application of the doctrine of equivalents to the ’974 patent, to which prosecution history estoppel does not apply, and as further support for a finding that the equivalents in question have been surrendered in the ’912, ’942 and ’247 patents.

I. Johnson & Johnston v. R.E. Service Co. Inc., 285 F.3d 1046, 1050 (Fed. Cir. 2002), held that “when a patent drafter discloses but declines to claim subject matter . . . this action dedicates unclaimed subject matter to the public.” Johnson & Johnston imposes a strict application of the dedication rule in its articulation of the primacy of the claims in defining the scope of a patentee’s exclusive rights. Johnson & Johnston affirmed the principle that “[o]ut of all the possible permutations of elements which can be made from the specifications, [a patentee] reserves for himself only those contained in the claims.” Id.

II. The ’942 and ’912 patents both claim a pharmaceutical composition consisting of a piperidinoalkanol compound and certain inert ingredients, including croscarmellose sodium (a superdisintegrant), pregelatinized starch (a binder), and microcrystalline cellulose (a cellulose diluent). The “written description” of the patent specifications identifies inert ingredients that can be present in amounts of up to 95 percent of the total pharmaceutical composition weight:

As used herein the term “inert ingredient” refers to those therapeutically inert ingredients that are well known in the art of pharmaceutical science which can be used singly or in various combinations … as are disclosed in The United States Pharmacopeia, XXII, 1990 … pages 1857-1859, which is incorporated herein by reference. For example, the following inert ingredients can be utilized singly or in various combinations; … povidone … [and] sodium starch glycolate. … The above inert ingredients can be present in amounts up to about 95% of the total composition by weight.

While identified in the specifications, the inert ingredients povidone, crospovidone, and sodium starch glycolate are not claimed. Mannitol and powdered cellulose are not expressly cited in the specifications, but are listed in the U.S. Pharmacopeia incorporated in the specification by reference.

III. Defendants argue that the ’942, ’912, ’974 and ’247 patents (variously) disclose the inert ingredients sodium starch glycolate, povidone, crospovidone, mannitol, corn starch and powdered cellulose in their specifications, but do not claim them. The patents, therefore, have dedicated those ingredients to the public, and under Johnson & Johnston, plaintiffs cannot now reclaim subject matter that has been disclosed.

By disclosing but not claiming povidone, crospovidone and sodium starch glycolate, the patents have dedicated these ingredients to the public, and cannot now reclaim these excipients through application of the doctrine of equivalents.

However, with respect to the ingredients mannitol, corn starch and powdered cellulose, these ingredients are not expressly recited in any of the patents’ specifications. Rather, mannitol and powdered cellulose are listed on page 1858 of the U.S. Pharmacopeia, incorporated in the patent specifications by reference. The mere description of ingredients belonging to the class “inert ingredient,” without a clearer indication that any ingredients so described are equivalents to the claimed excipients, does not constitute a clear or specific disclosure of subject matter such that a person of ordinary skill in the art would conclude, by reading the specification, that the patentee has dedicated the use of these ingredients to the public as alternatives to those claimed.

The ’974 patent disclosure of excipients that can “optionally” be included in addition to the claimed excipients similarly fails to give rise to the conclusion that these excipients were dedicated as equivalents to those claimed. The ’974 patent states, “Formulation (A) and (B) of the pharmaceutical compositions of the present invention optionally may contain one or more other pharmaceutically acceptable excipients.” Povidone and crospovidone are listed as such “other” excipients. In Johnson & Johnston, the disclosed element was clearly identified as an alternative to the claimed element, although a disfavored one. This court is not presented with analogous facts in this instance.

For these reasons, the ’912, ’942, and ’247 patents have dedicated the excipients povidone, crospovidone and sodium starch glycolate to the public. On this basis, and because of prosecution history estoppel, plaintiffs cannot now claim these ingredients as equivalents to those claimed. Although mannitol, corn starch and powdered cellulose have not been dedicated to the public by any of the patents at issue, plaintiffs are precluded from relying on the doctrine of equivalents by prosecution history estoppel, and cannot now assert these excipients as equivalents to claimed excipients in the ’912, ’942 and ’247 patents. Finally, the ’974 patent does not dedicate the excipients povidone and crospovidone to the public. As there has been no finding of prosecution history estoppel, plaintiffs may assert these excipients as equivalents to those claimed.

The ’872 Patent

The ’872 patent describes a fexofenadine hydrochloride drug formulation. Plaintiffs allege that claims 1 and 2 of the ’872 patent are infringed by defendants’ accused products. These independent claims are product-by-process claims. Product-by-process claims are not specified in the statutes governing patents. This category of claims is a judicial construct that evolved from a recognition that, due to the limitations of language, some products may be described only by the process used to make them.

The composition of claims 1 and 2 of the ’872 patent include a diluent, a disintegrant and a binding agent, while the composition of claim 2 also includes a lubricant. Claim 2 is identical to claim 1, except instead of reciting that “the dry granulation is screened,” it recites that “the dry granulation is combined with a lubricant.”

Defendants argue that their products do not infringe, and that claims 1 and 2 of the ’872 patent are invalid for anticipation by the prior art under 35 U.S.C. � 102(b). Plaintiffs argue that the ’872 patent is valid because the prior art references do not disclose each limitation of claims 1 and 2 of the ’872 patent, as they must to anticipate, and that defendants’ products infringe the claims, either literally or under the doctrine of equivalents.

I. A claim is invalid for anticipation if a single prior art reference published more than a year before the patent application was filed discloses each and every limitation set forth in a claim, either expressly or inherently. To invalidate the ’872 patent for anticipation by prior patents, the court must find that even if all material factual inferences are drawn in favor of plaintiffs, there is no reasonable basis on which plaintiffs can prevail.

A prior art reference must be enabling to anticipate. Plaintiffs bear the burden of presenting evidence that the prior art patents do not enable the ’872 inventions.

II. While product-by-process claims are not limited to the product prepared by the process set forth in the claims, process steps may establish product characteristics that are claim limitations. In an infringement or validity analysis, characteristics or product properties imparted by process steps recited in product-by-process claims are only relevant, however, to the extent that the resulting characteristics are claimed. Claims cannot be “saved” from invalidity by reading extraneous limitations not present in the claims.

Defendants asserted that the ’872 patent was anticipated by prior art patents ’605 and ’061. The ’605 and ’061 patents disclose a piperidinoalkanol formulation used in SELDANE(r) and SELDANE D(r), antihistamine products once sold by Aventis. Plaintiffs argue that these prior art references do not anticipate patent ’872, because they do not disclose fexofenadine compositions, a claimed element of the ’872 patent. Rather, both prior art references claim compositions of a piperidinoalkanol compound and identify terfenadine, a type of piperidinoalkanol compound, as the preferred active ingredient. Although both prior art patents incorporate by reference patents that describe fexofenadine, or, alternatively, piperidinoalkanol compounds, plaintiffs argue that this general incorporation by reference fails to meet requirements for a description necessary to anticipate.

The ’605 patent provides that “[t]he present invention relates to a pharmaceutical composition for oral administration of various piperidinoalkanol derivatives which are disclosed in [prior patents] the full disclosures of each patent being incorporated by reference.” The ’061 patent states that “[p]iperidinoalkanol derivatives which are useful as antihistamines are disclosed in [prior patents] and these patents are incorporated herein by reference.”

The court may consider the patents referred to in the quoted passage as incorporated into the ’605 and ’061 patents for purposes of the anticipation analysis. By their express language, these references bring within the four corners of the anticipatory reference the relevant elements of the prior art. The referenced patents are incorporated in their entirety. Moreover, the ’605 and ’061 patents refer specifically to these references for purposes of incorporating “piperidinoalkanol derivatives,” fexofenadine being one such derivative.

Plaintiffs further argue that even if patents ’605 and ’061 described the substitution of fexofenadine for terfenadine, they are not enabling because a person of ordinary skill in the field, directed to the prior art by the anticipatory reference, could not produce the invention. As described by plaintiffs, the inventors of the ’872 patent attempted to develop a fexofenadine tablet using the formulations set forth in the ’605 and ’061 patents, by substituting fexofenadine for terfenadine, and omitting a pseudoephedrine decongestant. The formulation that was produced contained, but for the substitutions described, the same combination of excipients as the formulations set forth in the ’605 and ’061 patents. When the formulation was administered to patients it was shown that the bioavailability of the formulation was unacceptably poor. (Bioavailability is the rate and extent to which the active ingredient or therapeutic ingredient is absorbed from a drug and becomes available at the site of drug action.) Plaintiffs claim that the ’605 and ’061 patents, therefore, cannot be said to enable the “novel” fexofenadine formulations of the ’872 patent, which have excellent bioavailability.

Bioavailibility, a desirable characteristic in a biochemical formulation, is not set forth either expressly or inherently as a limitation in the ’872 patent claims. For the court to accept plaintiffs’ argument that the prior art need enable a bioavailable formulation in order to anticipate, it would have to disregard the clear warnings of the Federal Circuit against importing claim limitations based on terms not mentioned in the claim. Amgen Inc. v. Hoechst Marion Roussel, 314 F.3d 1313, 1325 (Fed. Cir. 2003).

In short, the prior art need not enable a bioavailable fexofenadine formulation in order to be deemed anticipating.

Conclusion

Defendants’ motion for summary judgment of noninfringement of the ’912, ’942 and ’247 patents is granted, and defendants’ motion for summary judgment of noninfringement of the ’974 patent is denied. A ruling on the ’872 patent is reserved pending a Markman hearing to assist this court in construing the patent’s product-by-process claims.

� Digested by Steven P. Bann

[The slip opinion is 47 pages long.]

For plaintiffs: Aventis Pharmaceuticals Inc. et al � Gerald Sobel, Joel Katcoff and David K. Barr, of the N.Y. bar (Kaye Scholer); Merrell Pharmaceuticals Inc. et al � Tricia B. O’Reilly and Liza M. Walsh (Connell Foley). For defendants: Impax Laboratories Inc. � Richard S. Gresalfi and Stephen J. Lee, of the N.Y. bar (Kenyon & Kenyon) and Allyn Z. Lite (Lite, DePalma, Greenberg & Rivas); Barr Laboratories Inc. � Glenn J. Pfadenhauer, George A. Borden and Bonnie Dunninger Nathan, of the D.C. bar (Williams & Connelly), and Robert M. Goodman and C. Brian Kornbrek (Greenbaum, Rowe, Smith, Ravin, Davis & Himmel); Mylan Pharmaceuticals Inc. � E. Anthony Figg and Elizabeth A. Leff, of the D.C. bar (Rothwell, Figg, Ernst & Manbeck) and Arnold B. Calmann and Jeffrey Soos (Saiber, Schlesinger, Satz & Goldstein); Reddy’s Laboratories Ltd. � Thomas G. Roth and Thomas C. Pontani, Martin B. Pavane and Alfred H. Hemingway, of the N.Y. bar (Cohen Pontani Lieberman & Pavane).