United States Court of Appeals for the Federal Circuit
2006-1572
IN RE GABAPENTIN PATENT LITIGATION
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WARNER-LAMBERT CO., PFIZER, INC.,
and GODECKE AKTIENGESELLSCHAFT,
Plaintiffs-Appellants,
v.
PUREPAC PHARMACEUTICAL CO. and FAULDING, INC.,
Defendants-Appellees,
and
WATSON LABORATORIES, INC., WATSON PHARMACEUTICALS, INC.,
WATSON PHARMA, INC., and DANBURY PHARMACAL, INC.,
Defendants,
and
TEVA PHARMACEUTICAL INDUSTRIES, LTD. and TEVA PHARMACEUTICALS USA, INC.,
ZENITH LABORATORIES, INC. (now known as IVAX Pharmaceuticals NV, Inc.), ZENITH
GOLDLINE PHARMACEUTICALS, INC. (now known as IVAX Pharmaceuticals, Inc.)
and IVAX CORP.,
Defendants-Appellees,
and
APOTEX CORP., APOTEX, INC., and TORPHARM, INC.,
Defendants-Appellees,
and
EON LABS MANUFACTURING, INC.,
Defendant-Appellee.
Jack B. Blumenfeld, Morris, Nichols, Arsht & Tunnell LLP, of Wilmington,
Delaware, argued for plaintiffs-appellants. With him on the brief were Karen Jacobs
Louden, Benjamin Schladweiler, and Richard J. Bauer.
Edgar H. Haug, Frommer Lawrence & Haug LLP, of New York, New York, argued
for defendants-appellees, Purepac Pharmaceutical Co. and Faulding, Inc. With him on
the brief were Steven M. Amundson and Andrew S. Chalson.
Steven J. Lee, Kenyon & Kenyon LLP, of New York, New York, argued for
defendants-appellees, Teva Pharmaceutical Industries, Ltd., et al. With him on the brief
was Elizabeth Holland. Of counsel were William G. James, II and Patrice P. Jean of
Washington, DC.
Richard J. Basile, St. Onge Steward Johnston & Reens LLC, of Stamford,
Connecticut, for defendant-appellee, Eon Labs Manufacturing, Inc. With him on the brief
were Stephen P. McMamara and Stanley H. Lieberstein. Of counsel were James P.
Jeffry and Benjamin J. Lehberger.
Appealed from: United States District Court for the District of New Jersey
Judge John C. Lifland
United States Court of Appeals for the Federal Circuit
2006-1572
IN RE GABAPENTIN PATENT LITIGATION
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WARNER-LAMBERT CO., PFIZER, INC.,
and GODECKE AKTIENGESELLSCHAFT,
Plaintiffs-Appellants,
v.
PUREPAC PHARMACEUTICAL CO. and FAULDING, INC.,
Defendants-Appellees,
and
WATSON LABORATORIES, INC, WATSON PHARMACEUTICALS, INC.,
WATSON PHARMA, INC., and DANBURY PHARMACAL, INC.,
Defendants,
and
TEVA PHARMACEUTICAL INDUSTRIES, LTD. and TEVA PHARMACEUTICALS USA,
INC., ZENITH LABORATORIES, INC. (now known as IVAX Pharmaceuticals NV, Inc.),
ZENITH GOLDLINE PHARMACEUTICALS, INC. (now known as IVAX
Pharmaceuticals, Inc.) and IVAX CORP.,
Defendants-Appellees,
and
APOTEX CORP., APOTEX, INC., and TORPHARM, INC.,
Defendants-Appellees,
and
EON LABS MANUFACTURING, INC.,
Defendant-Appellee.
_____________________
DECIDED: September 21, 2007
_____________________
Before LOURIE, LINN, and MOORE, Circuit Judges.
LOURIE, Circuit Judge.
Warner Lambert Co., Pfizer Inc., and Gödecke Aktiengesellschaft (collectively
“Warner Lambert”) appeal from the judgment of the United States District Court for the
District of New Jersey granting summary judgment of noninfringement of claims 7-11 of
U.S. Patent 6,054,482 (“the ’482 patent”) in favor of appellees Purepac Pharmaceutical
Co., Faulding Inc., Teva Pharmaceutical Industries, Inc., Teva Pharmaceuticals USA,
Inc. (collectively “Teva”), Zenith Laboratories, Inc. (now known as IVAX
Pharmaceuticals NV, Inc.), Zenith Goldline Pharmaceuticals, Inc. (now known as IVAX
Pharmaceuticals, Inc), IVAX Corp. (collectively “IVAX”), and Eon Labs Manufacturing,
Inc. (generic defendants collectively referred to as “appellees”). Because we conclude
that the district court erred in determining that there were no genuine issues of material
fact concerning whether Warner Lambert failed to meet its burden of proof that the
accused products infringe the asserted claims of the ’482 patent, we reverse and
remand. Because we conclude that the district court did not err in construing the
disputed claim limitations, we affirm those aspects of the district court’s decision.
BACKGROUND
Warner Lambert manufactures and sells Neurontin®, a drug used to treat certain
cerebral disorders, including epilepsy. The active ingredient in Neurontin® is a
compound called gabapentin, which is covered by Warner Lambert’s ’482 patent. That
patent, entitled “Lactam-Free Amino Acids,” is directed towards a process for the
preparation of, and compositions containing, gabapentin substantially free from a lactam
contaminant. ’482 patent col.2 ll.27-29.
2006-1572 2
Warner Lambert scientists discovered that under certain conditions gabapentin
has a tendency to form a lactam, which makes the drug unstable and unsafe. The
lactam was shown to be twenty-five times more toxic than gabapentin, and is linked to
causing seizures, rather than preventing them. In re Gabapentin Patent Litig., 393 F.
Supp. 2d 278, 280 (D.N.J. 2005). In an effort to minimize the formation of lactam during
the manufacturing process, Warner Lambert developed a process disclosed and
claimed in the ’482 patent. Warner Lambert determined that two limitations must be
observed in the process in order to achieve stable formations of gabapentin.
First, the ’482 patent discloses that gabapentin must be highly purified before
being formulated into the pharmaceutical preparation. While drug manufacturers
generally prefer to use salt forms of an active ingredient over the free base form
because salts “usually provide good stability and good solubility,” ’482 patent col.3 ll.61-
65, Warner Lambert determined that gabapentin hydrochloride was less stable than free
gabapentin. Id. col.3 ll.65-67. Thus, Warner Lambert sought to keep lactam formation
to a minimum by preparing gabapentin in its highly purified form. The ’482 patent
discloses that:
The active materials of formula (I) must be prepared as highly purified,
nonderivatized free amino acids, for example, from the corresponding
hydrochloride by ion exchange. The proportion of remaining hydrochloride
admixtures should thereby not exceed 20 ppm. The same also applies to
other mineral acids.
Id. col.5 ll.24-29. Thus, the patent teaches that in preparing purified gabapentin, the
hydrochloride admixture, or other mineral acid, remaining from the manufacturing
process should not exceed twenty parts per million (“20 ppm”).
2006-1572 3
Second, Warner Lambert determined that certain adjuvants that reduce the
stability of gabapentin must be avoided. The ’482 patent further discloses that:
The following adjuvant materials, for example, reduced the stability of the
compounds (I) and should be avoided in the preparation of pharmaceutical
compositions: modified maize starch, sodium croscarmelose, glycerol
behenic acid ester, methacrylic acid co-polymers (types A and C), anion
exchangers titanium dioxide, and silica gels such as Aerosil 200.
Id. col.5 ll.5-10.
Pursuant to the Hatch-Waxman Act, Warner Lambert filed suit against several
generic drug companies that filed Abbreviated New Drug Applications (“ANDAs”) with
the Food and Drug Administration. 1 Those companies sought approval to market
generic versions of Neurontin®. In their ANDAs, appellees committed to using Teva’s
gabapentin active pharmaceutical ingredient in their products. Gabapentin, 393 F.
Supp. 2d at 283. Under the direction of the Judicial Panel on Multidistrict Litigation, the
actions were consolidated for pretrial proceedings in the United States District Court for
the District of New Jersey. Between 2001 and 2003, appellees filed various summary
judgment motions, including motions for summary judgment of noninfringement and
invalidity. During the pendency of those motions, Warner Lambert sought a preliminary
injunction to enjoin IVAX, Purepac, and Teva from launching their products. Those
motions were denied.
On August 25, 2005, the district court issued several rulings on the summary
judgment motions. The court construed numerous claim terms. At issue in this appeal
1
After filing suit against appellees, Warner Lambert filed similar lawsuits against
other generic drug manufacturers. Appellees, who belong to the first group of
defendants Warner Lambert sued, are “first wave” defendants. “Second” and “third”
wave defendants, whose cases have also been consolidated for pretrial purposes with
the underlying multidistrict litigation, are not part of the instant appeal.
2006-1572 4
are two of those terms, namely, “anion of a mineral acid” and “adjuvant.” Those terms
appear in representative claim 7, which has been asserted against appellees. It claims:
7. A stable and pure pharmaceutical composition in unit dry medicinal
dosage form consisting essentially of:
(i) an active ingredient which is gabapentin in the free amino acid,
crystalline anhydrous form containing less than 0.5% by weight of its
corresponding lactam and less than 20 ppm of an anion of a mineral acid
and
(ii) one or more pharmaceutically acceptable adjuvants that do not
promote conversion of more than 0.2% by weight of the gabapentin to its
corresponding lactam form when stored at 25ºC and an atmospheric
humidity of 50% for one year.
’482 patent claim 7 (emphases added). Based on the intrinsic evidence, the court
construed “anion of a mineral acid” as an “anion derived from a mineral acid.” In re
Gabapentin Patent Litig., 395 F. Supp. 2d 153, 163 (D.N.J. 2005). The court further
construed “adjuvants” as a “subset of [eight particular] inactive ingredients that is
intimately mixed with gabapentin to form the drug mixture, and thus [does not] refer to
the ingredients of capsule shells or tablet coatings.” In re Gabapentin Patent Litig., 395
F. Supp. 2d 140, 152 (D.N.J. 2005).
The district court granted appellees’ motion for summary judgment of
noninfringement based on Warner Lambert’s failure to meet its burden of proof. The
court determined that Warner Lambert failed to adduce sufficient evidence to establish
that the accused products meet the limitation that the anions of a mineral acid do not
exceed 20 ppm (“the 20 ppm limitation”). In opposing the motion for summary
judgment, Warner Lambert submitted results from a comparative pH test performed by
its analytical expert. Warner Lambert argued that those results created a genuine issue
of material fact regarding whether the accused products met the 20 ppm limitation.
2006-1572 5
Based on the undisputed fact that the test had a ± 5 ppm margin of error, the court
determined that that evidence was insufficiently precise to prove infringement, and thus
granted summary judgment in favor of appellees.
On July 13, 2006, the court entered judgment of noninfringement based on the
burden of proof motion in favor of appellees, pursuant to Federal Rule of Civil
Procedure 54(b). Warner Lambert timely appealed. We have jurisdiction pursuant to
28 U.S.C. § 1295(a)(1).
DISCUSSION
We review the district court’s grant of summary judgment de novo, reapplying the
standard applicable at the district court. See Rodime PLC v. Seagate Tech., Inc., 174
F.3d 1294, 1301 (Fed. Cir. 1999). Summary judgment is appropriate “if the pleadings,
depositions, answers to interrogatories, and admissions on file, together with the
affidavits, if any, show that there is no genuine issue as to any material fact and that the
moving party is entitled to judgment as a matter of law.” Fed. R. Civ. P. 56(c). In
addition, in deciding a motion for summary judgment, “[t]he evidence of the nonmovant
is to be believed, and all justifiable inferences are to be drawn in his favor.” Anderson v.
Liberty Lobby, Inc., 477 U.S. 242, 255 (1986).
A determination of infringement requires a two-step analysis. “First, the court
determines the scope and meaning of the patent claims asserted. . . . [Second,] the
properly construed claims are compared to the allegedly infringing device.” Cybor Corp.
v. FAS Techs., Inc., 138 F.3d 1448, 1454 (Fed. Cir. 1998) (en banc) (citations omitted).
Step one, claim construction, is an issue of law, Markman v. Westview Instruments,
Inc., 52 F.3d 967, 970-71 (Fed. Cir. 1995) (en banc), aff’d, 517 U.S. 370 (1996), that we
2006-1572 6
review de novo, Cybor, 138 F.3d at 1456 (Fed. Cir. 1998). Step two, comparison of the
claim to the accused device, requires a determination that every claim limitation or its
equivalent be found in the accused device. See Warner-Jenkinson Co. v. Hilton Davis
Chem. Co., 520 U.S. 17, 29 (1997). Those determinations are questions of fact, and on
summary judgment, the issue is whether there is no genuine issue of material fact
regarding infringement. Bai v. L & L Wings, Inc., 160 F.3d 1350, 1353 (Fed. Cir. 1998).
I.
On appeal, Warner Lambert argues that the district court erred by resolving
factual disputes on summary judgment. According to Warner Lambert, the parties
proffered conflicting expert opinions, based on different evidence and different methods
of testing, regarding whether Teva’s samples infringed the ’482 patent. As such,
Warner Lambert argues that genuine issues of material fact exist in the record, and thus
summary judgment was not appropriate. Warner Lambert further argues that the district
court applied the wrong legal standard. Warner Lambert argues that the court, instead
of determining whether it was more likely than not that a particular sample could meet
the 20 ppm claim limitation, improperly determined whether it was possible that that
sample could exceed the 20 ppm limitation.
Appellees respond that the court properly granted summary judgment for several
reasons. First, appellees challenge the accuracy and reliability of the pH testing
method. Appellees assert that the pH testing method yielded inaccurate results
because, inter alia, Warner Lambert’s expert failed to calibrate the standards used for
the test. Second, appellees argue that pH testing is not competent proof of infringement
in light of the test’s lack of precision. Because the pH testing method cannot quantify
2006-1572 7
the level of acidic chloride in a gabapentin sample, as Warner Lambert purportedly
conceded, appellees argue that that evidence was insufficient to raise a genuine issue
of material fact. As such, appellees contend that summary judgment was proper
because appellees’ evidence showing that the samples contained more than 20 ppm of
acidic chloride stood unrebutted.
We agree with Warner Lambert that genuine issues of material fact exist in the
record, and thus that the court erred in granting summary judgment. In support of its
motion for summary judgment, appellees adduced evidence demonstrating that the
Teva samples contained over 20 ppm of acidic chloride. 2 To counter that evidence,
Warner Lambert submitted results from pH tests that were performed by Warner
Lambert’s analytical expert, Dr. Martin C. Davies. In conducting the comparative pH
testing, Dr. Davies measured pH levels of the Teva samples against standards with
known levels of acid. Dr. Davies prepared the standards by first preparing a baseline
sample that contained no detectable chloride. Various known amounts of acid were
then added to the baseline sample, and the pH measurements of the standard samples
were recorded. The pH measurements of the standards generally decreased as the
amount of mineral acid increased. Conversely, the pH measurements increased as the
amount of mineral acid decreased. The pH values of numerous Teva samples were
then measured. The record contains a chart prepared by Dr. Davies that compares
those values to the pH measurements of the standard samples. The chart, reproduced
2
Because hydrochloric acid (“HCl”) is the mineral acid of interest in this action,
the relevant inquiry is whether Teva’s samples meet the requirement that they contain
less than 20 ppm of anions derived from HCl. Anions derived from HCl are referred to
as “acid-derived chloride ions” or “acidic chlorides.” We will refer to the relevant anions
as “acidic chloride” throughout the opinion.
2006-1572 8
below, includes pH measurements of seven Teva samples. The last five samples,
288074001-859173601, represent samples made according to a process that Teva
implemented after the issuance of the ’482 patent, and thus are relevant to our analysis.
The results revealed, in pertinent part, the following:
For purposes of this appeal, the standard sample containing 12 ppm of chloride, which
had a pH value of 6.98, is dispositive of the issue before us. Standing alone, that
standard indicates that a sample with a pH of 6.98 would have 12 ppm of acidic
chloride, which would meet the 20 ppm limitation. Taking into account the test’s margin
of error of ± 5 ppm, the 12 ppm standard further indicates that a sample with a pH of
6.98 could have between 7 to 17 ppm of acidic chloride—a range that falls within the 20
ppm claim limitation. Significantly, four out of the five relevant Teva samples had pH
values that were greater than 6.98, 3 which, according to Dr. Bartlett, indicates that those
four samples contained not more than 17 ppm of acidic chloride, thereby also meeting
3
The pertinent data with regard to the Teva samples are found in the first row,
which represents pH values for pure gabapentin samples, i.e., samples to which no HCl
was added.
2006-1572 9
the 20 ppm claim limitation. 4 See J.A. 1459-60. Drawing all reasonable inferences in
favor of Warner Lambert as the nonmovant, we conclude that Warner Lambert adduced
sufficient evidence to create a genuine issue of material fact regarding whether Teva’s
samples met the 20 ppm claim limitation of the ’482 patent. Accordingly, the district
court erred in granting summary judgment.
We are unpersuaded by appellees’ complaint concerning the validity of the
comparative pH testing method. In moving for summary judgment of noninfringement
based on Warner Lambert’s inability to meet its burden of proof, appellees informed the
district court that:
It is important to note for the record that Defendants strongly dispute the
capability of pH testing to make any scientifically meaningful distinctions
between gabapentin samples at the trace levels of acidity relevant to the
’482 patent. However, for purposes of this motion, Defendants have
placed that dispute to one side (as they must), and focused on the
undisputed limitations on the precision of such comparative pH
measurements.
Indeed, at the summary judgment hearing, appellees expressly stated that:
Teva’s experts vehemently dispute the validity of the data [Dr. Bartlett]
relied on, but I want to ignore that dispute. Those factual issues are in
dispute, but should not be part of this motion, and we, you can ignore
them.
Thus, appellees limited their summary judgment motion to the issue of the undisputed
limits of the test’s precision, viz., the ± 5 ppm margin of error, which we have
considered. As such, appellees waived any argument challenging the validity, including
4
A higher pH value represents lower acidity. Gabapentin, 393 F. Supp. 2d at
284. Thus, “[i]f the pH of the unknown sample measures higher than a particular
standard, then that sample must contain less acid,” and hence a lesser amount of acidic
chlorides, than the standard. Id. at 285.
2006-1572 10
challenges to the accuracy or reliability, of the pH testing method for purposes of
summary judgment.
Moreover, we are not persuaded by appellees’ argument that summary judgment
was proper because Warner Lambert failed to prove infringement in quantitative terms.
Appellees rely on Abbott Laboratories v. TorPharm, Inc., 300 F.3d 1367 (Fed. Cir.
2002), and Zenith Laboratories, Inc. v. Bristol-Myers Squibb Co., 19 F.3d 1418 (Fed.
Cir. 1994), in support of their argument that infringement must be proven using a test
that can quantify the level of acidic chloride in a gabapentin sample because Warner
Lambert chose to draft its claims in quantitative terms. Appellees’ reliance on the cited
authority is misplaced. In Abbott, the patentee defined the scope of his claims in terms
of “oligomeric structure and the number of repeating units.” 300 F.3d at 1376. We
concluded that the patentee was required to demonstrate infringement in terms of those
properties, rather than rely on molecular weight measurements that purportedly failed
“to provide proof of molecular structure.” Id. at 1377. Similarly, in Zenith, the patentee
drafted his claims in terms of x-ray diffraction properties. We stated that “the scientific
theories utilized must establish the presence of the limitations recited in the claim,” and
thus found that two types of tests proffered by the patentee, namely, visual observation
and birefringence comparison, were only “inferentially relevant” in proving infringement
because they failed to establish whether crystals possessed the claimed x-ray
diffraction properties. 19 F.3d at 1423.
Here, in order to prove infringement, Warner Lambert is required to demonstrate
that the Teva samples contain less than 20 ppm of anions of a mineral acid, as recited
in the claims. Based on the record before us, the comparative pH testing allows for this
2006-1572 11
showing. Unlike the evidence relied on in Abbott and Zenith, pH testing can indicate
whether a sample contains less than 20 ppm of acidic chloride by measuring the pH, or
acidity, of the solution and comparing it against a sample with a known amount of acid.
Dr. Bartlett opined that “[i]f the pH of the unknown sample measures higher than a
particular standard, then that sample must contain less acid than the standard. Using
the comparative pH technique, one can thus determine whether the unknown sample
falls within the acid limitation of the ’482 patent.” To the extent appellees are arguing
that the comparative pH testing method is invalid, inaccurate, or unreliable, as
discussed above, appellees waived that argument for purposes of summary judgment.
Accordingly, based on the record before us, we conclude that the district court
erred in granting summary judgment of noninfringement based on Warner Lambert’s
purported failure to meet its burden of proof. The record shows that Warner Lambert
proffered sufficient evidence to create a genuine issue of material fact regarding
whether the accused products met the 20 ppm claim limitation of the ’482 patent.
II.
Appellees argue in the alternative that the judgment can be affirmed because the
court erred in its construction of the “anion of a mineral acid” and adjuvant claim
limitations, and that they should still be awarded judgment, but based on what they
consider to be the correct claim interpretation. Appellees assert that based on the
intrinsic evidence, and the prosecution history in particular, “anion of a mineral acid”
refers to anions from any source capable of forming a mineral acid. In essence,
appellees assert that the term refers to total chloride content and is not limited to acid-
derived chloride ions. Under that interpretation, they argue they do not infringe.
2006-1572 12
Appellees further argue that the court correctly concluded that the adjuvant limitation
excludes the eight adjuvants identified in the specification of the ’482 patent, but erred
in concluding that the adjuvant must be intimately mixed with the gabapentin.
According to appellees, adjuvant refers to any ingredient other than the active
ingredient, and thus encompasses ingredients included in the capsule shell or tablet
coating. Because certain accused products include titanium dioxide, one of the
excluded adjuvants, in the capsule shell or tablet coating, appellees contend that those
products do not infringe. Appellees also challenge the court’s construction of the term
“modified maize starch,” which is identified as one of the adjuvants to be avoided.
Under the proper construction of that term, which appellees argue would include
pregelatinized starch, appellees contend that their samples likewise would not infringe.
Warner Lambert responds that the court’s construction of those terms was
correct. As for “anion of a mineral acid,” Warner Lambert contends that appellees’
proffered construction would read the term “of a mineral acid” out of the claims.
Additionally, Warner Lambert asserts that the court’s construction is correct in light of
the intrinsic evidence and the purpose of the invention. With respect to the adjuvant
limitation, Warner Lambert argues that appellees are precluded from appealing that
issue because it was not the subject of the Rule 54(b) motion. In the alternative,
Warner Lambert asserts that appellees’ proposed constructions are contrary to both the
intrinsic and extrinsic evidence.
We first address the claim limitation of “anion of a mineral acid,” which is present
in every asserted claim of the ’482 patent. We agree with the district court that the
proper construction is “anion derived from a mineral acid.” In re Gabapentin Patent
2006-1572 13
Litig., 395 F. Supp. 2d 153, 159 (D.N.J. 2005). “It is a ‘bedrock principle’ of patent law
that ‘the claims of a patent define the invention to which the patentee is entitled the right
to exclude.’” Phillips v. AWH Corp., 415 F.3d 1303, 1327 (Fed. Cir. 2005) (quoting
Innova/Pure Water, Inc. v. Safari Water Filtration Sys., Inc., 381 F.3d 1111, 1115 (Fed.
Cir. 2004)). Here, the plain language of the claim supports the construction that the
anion specifically is derived from a mineral acid. Appellees’ assertion that the claimed
anion refers to total chloride ions or anions from any source that is “capable of” forming
a mineral acid is unsupported by the claim language. Had the patentees intended the
anion to refer to any anion, regardless of its source, the patentees could have simply
claimed “anions” and omitted the phrase “of a mineral acid.” Thus, the construction
adopted by the district court gives full meaning to every word of the entire claim term.
Bicon, Inc. v. Straumann Co., 441 F.3d 945, 950 (Fed. Cir. 2006) (“claims are
interpreted with an eye toward giving effect to all terms in the claim”). Moreover,
reference to other claims of the patent further supports this definition. Dependent
claims 2, 5, 6, and 11 specify that the mineral acid is hydrochloric acid. Those
dependent claims would be superfluous or unnecessary if the anions did not derive from
mineral acids because there would be no need to identify with particularity the type of
mineral acid that must be used. Therefore, based on the claim language, we conclude
that the district court did not err in its construction.
We have also held that claims “must be read in view of the specification, of which
they are a part.” Phillips, 415 F.3d at 1315. While appellees argue that the specification
provides no support for their construction, we find that the specification provides further
support for the construction adopted by the district court. The specification teaches a
2006-1572 14
multi-step process for making gabapentin that is substantially free from lactam. ’482
patent Abstract, col.1 l.41-col.2 l.21. The Summary of the Invention describes a three-
step process as:
(a) treating a compound of formula VII substantially free from compound
VIII with a semiconcentrated mineral acid, converting the lactam VIII into
VII,
(b) removing the anions of the mineral acid by ion exchange, leaving the
purified VII, and
(c) converting the product of step (b) to a pharmaceutically acceptable
salt thereof, if desired.
Id. col.2 ll.1-8 (emphases added). The specification then states that “[a] preferred
process of the instant invention is one wherein the mineral acid hydrochloric acid is
used and an ion exchanger is used for anion removal.” Id. col.2 ll.9-10. That disclosure
further supports the conclusion that the anions that are to be removed are specific to the
mineral acid that was used in the first step of the process, and do not derive from any
other possible source.
We are not persuaded by appellees’ extensive reliance on the prosecution history
in support of their construction, particularly in this case where the claim language
provides a clear definition of the disputed claim term, supported by the specification.
Based on our review of the prosecution history, we find no basis for reversing the district
court’s construction, which we have already determined comports with the claim
language and specification. Accordingly, we conclude that the district court did not err
in its construction of the claim term “anion of a mineral acid.”
We next consider appellees’ arguments concerning adjuvants. As a preliminary
matter, we disagree with Warner Lambert’s assertion that the adjuvant issue is not
2006-1572 15
properly before us because it falls outside the scope of the Rule 54(b) judgment. Rule
54(b) provides that:
When more than one claim for relief is presented in an action, whether as
a claim, counterclaim, cross-claim, or third-party claim, or when multiple
parties are involved, the court may direct the entry of a final judgment as
to one or more but fewer than all of the claims or parties only upon an
express determination that there is no just reason for delay and upon an
express direction for the entry of judgment.
Here, finding no just reason for delay, the district court entered final judgment on
Warner Lambert’s infringement claims. In reaching its decision to grant the request for
certification under Rule 54(b), the district court reasoned that “Federal Circuit review of
the Court’s claim constructions and noninfringement rulings will advance the ultimate
resolution of this multidistrict litigation.” R. 54(b) Order, slip op. at 3. The court further
stated that “appellate review will benefit the parties in this multidistrict litigation by
providing definitive claim constructions, which should narrow the issues.” Id. at 4.
Thus, contrary to Warner Lambert’s assertion, the court’s entry of final judgment on the
issue of noninfringement was not limited to two particular motions, viz., the burden of
proof motion or Apotex’s adjuvant motion, but rather encompassed the court’s claim
construction rulings that pertained to the issue of noninfringement. As such, the court’s
claim construction of the adjuvant limitation, which is relevant to a noninfringement
determination, is properly before us.
We agree with Warner Lambert that the district court did not err in concluding
that the adjuvant claim limitation refers to ingredients intimately mixed with gabapentin,
and thus excludes ingredients located in the capsule shell or tablet coating. In reaching
its determination, the court first examined the claim language. The court noted that
claim 7 claimed “a stable and pure pharmaceutical composition in unit dry medicinal
2006-1572 16
dosage form,” thus suggesting a distinction between ingredients that are mixed with the
active ingredients and ingredients that are separated from the active ingredient because
they are in the tablet coating or capsule shell. Gabapentin, 395 F. Supp. 2d at 151-52.
The court then considered the specification and correctly observed that the patentees
were concerned with the negative effect certain adjuvants had on the stability of
gabapentin because those adjuvants catalyzed lactam formation. The court concluded
that “that concern is most relevant where the catalyst is intimately mixed with the
reactive material, suggesting to the Court that peripheral or partial contact, as in a
capsule shell or tablet film coating, between a catalyst and the reactive material was of
lesser concern.” Id. at 152. Moreover, the court found nothing in the patent or
prosecution history indicating that ingredients found in the capsule shell or coating
affects stability, and also relied on several dictionary definitions in support of its
construction. We find no error in the court’s analysis, and are not persuaded by
appellees’ arguments in support of a broader definition. Accordingly, we conclude that
the court did not err in determining that the asserted claims require the adjuvant to be
intimately mixed with gabapentin.
Lastly, we reject appellees’ assertion that the court erred in construing “modified
maize starch” as “maize starch modified by acid treatment.” In reaching its conclusion,
the court first examined the ’482 patent specification. The specification discloses that:
The following adjuvant materials, for example, reduced the stability of the
compounds (I) and should be avoided in the preparation of pharmaceutical
compositions: modified maize starch, sodium croscarmelose, glycerol
behenic acid ester, methacrylic acid co-polymers (types A and C), anion
exchangers titanium dioxide, and silica gels such as Aerosil 200.
On the other hand, the following adjuvant materials had no noticeable
influence on the stability of the compounds (I):
2006-1572 17
hydroxypropylmethylcellulose, polyvinylpyrrolidone, crospovidon,
poloxamer 407, poloxamer 188, sodium starch glycolate, copolyvidone,
maize starch, cyclodextrin, lactose, talc, as well as co-polymers of
dimethylamino-methacrylic acid and neutral methacrylic acid ester.
’482 patent col.5 ll.5-17 (emphases added). The court noted that while the specification
expressly indicated that modified maize starch should be avoided as an adjuvant, the
specification further stated that sodium starch glycolate, which, according to Warner
Lambert’s expert, Dr. Klibanov, is an example of pregelatinized starch, “had no
noticeable influence on the stability of the compounds.” That supports the court’s
construction that modified maize starch does not encompass pregelatinized starch;
otherwise the teaching of the specification would be internally inconsistent.
In addition, the court relied on the prosecution history in support of its
construction. The prosecution history contains a declaration dated December 10, 1999,
by Dr. Friedrich Tröndlin, then-head of the analytical department of Parke-Davis
Analytical Research. Dr. Tröndlin stated that “it is my belief that excipients pretreated
with mineral acids, such as maize starch modified by acid treatment would not result in
a stable formulation.” That statement provides further support for the construction
adopted by the district court. Based on those references to the intrinsic evidence, we
thus conclude that modified maize starch refers to maize starch modified by acid
treatment, which therefore excludes pregelatinized starch.
We have considered appellees’ arguments regarding the court’s claim
construction and find none that warrant reversal of the district court’s decision. In light
of our conclusion, we thus reject appellees’ alternative argument for noninfringement.
2006-1572 18
CONCLUSION
For the foregoing reasons, we reverse the district court’s grant of summary
judgment of noninfringement, affirm the court’s claim construction of the “anion of a
mineral acid” and adjuvant claim limitations, and remand for further proceedings
consistent with this opinion.
REVERSED IN PART, AFFIRMED IN PART, AND REMANDED
2006-1572 19