Case 1:13-cv-01674-RGA Document 296 Filed 06/26/15 Page 1 of 8 PageID #: 6688
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`IN THE UNITED STATES DISTRICT COURT
`FOR THE DISTRICT OF DELA WARE
`
`RECKITT BENCKISER
`PHARMACEUTICALS INC., RB
`PHARMACEUTICALS LIMITED, and
`MONOSOL RX, LLC,
`
`Plaintiffs,
`
`Civil Action No. 13-1674-RGA
`
`V.
`
`WATSON LABORATORIES, INC.,
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`Defendant.
`
`RECKITT BENCKISER
`PHARMACEUTICALS INC., RB
`PHARMACEUTICALS LIMITED, and
`MONOSOL RX, LLC,
`
`Plaintiffs,
`
`Civil Action No. 14-0422-RGA
`
`V.
`
`PAR PHARMACEUTICAL, INC.,
`INTELGENX TECHNOLOGIES CORP.
`
`Defendant
`
`MEMORANDUM OPINION
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`Dana Severance, Esq., Wilmington, DE, Womble Carlyle Sandridge Rice; Dan Ladow,
`Esq. (argued), New York, NY, Troutman Sanders LLP; Magnus Essunger, Esq., New York, NY,
`Troutman Sanders LLP; Andrew Regan, Esq., New York, NY, Troutman Sanders LLP; Cassandra
`Adams, Esq., New York, NY, Steptoe & Johnson LLP; Attorneys for Plaintiffs
`
`Kate Lester, Esq., Wilmington, DE, Richards, Layton & Finger, PA; Daniel Brown, Esq.
`(argued), New York, NY, Latham & Watkins LLP; Michelle Ma, Esq., Menlo Park, Latham &
`Watkins LLP; Jack Phillips, Esq., Wilmington, DE, Phillips, Goldman & Spence, P.A.;
`Attorneys for Defendants
`
`June 26._, 2015
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`I
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`

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`Case 1:13-cv-01674-RGA Document 296 Filed 06/26/15 Page 2 of 8 PageID #: 6689
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`Before this Court is a supplemental claim construction of a single term of U.S. Patent No.
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`8,475,832 ("the '832 Patent"). The Court previously construed other disputed terms submitted
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`by the parties. (D.I. 156). In the present matter, the Court has considered the parties' claim
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`construction briefing (D.I. 237, 239, 243, 253) and held a Markman hearing. (D.I. 294).
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`I.
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`LEGAL STANDARD
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`"It is a bedrock principle of patent law that the claims of a patent define the invention to
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`which the patentee is entitled the right to exclude." Phillips v. AWH Corp., 415 F.3d 1303, 1312
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`(Fed. Cir. 2005) (en bane) (internal quotation marks omitted). "' [T]here is no magic formula or
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`catechism for conducting claim construction.' Instead, the court is free to attach the appropriate
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`weight to appropriate sources 'in light of the statutes and policies that inform patent law."'
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`Soft View LLC v. Apple Inc., 2013 WL 4758195, at* 1 (D. Del. Sept. 4, 2013) (quoting Phillips,
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`415 F.3d at 1324). When construing patent claims, a court considers the literal language of the
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`claim, the patent specification, and the prosecution history. Markman v. Westview Instruments,
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`Inc., 52 F.3d 967, 977-80 (Fed. Cir. 1995) (en bane), afj"d, 517 U.S. 370 (1996). Of these
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`sources, "the specification is always highly relevant to the claim construction analysis. Usually,
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`it is dispositive; it is the single best guide to the meaning of a disputed term." Phillips, 415 F.3d
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`at 1315 (internal quotation marks and citations omitted).
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`"[T]he words of a claim are generally given their ordinary and customary meaning ....
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`[Which is] the meaning that the term would have to a person of ordinary skill in the art in
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`question at the time of the invention, i.e., as of the effective filing date of the patent application."
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`Id. at 1312-13 (internal quotation marks and citations omitted). "[T]he ordinary meaning of a
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`claim term is its meaning to [an] ordinary artisan after reading the entire patent." Id. at 1321
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`Case 1:13-cv-01674-RGA Document 296 Filed 06/26/15 Page 3 of 8 PageID #: 6690
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`(internal quotation marks omitted). "In some cases, the ordinary meaning of claim language as
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`understood by a person of skill in the art may be readily apparent even to lay judges, and claim
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`construction in such cases involves little more than the application of the widely accepted
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`meaning of commonly understood words." Id at 1314 (internal citations omitted).
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`When a court relies solely upon the intrinsic evidence-the patent claims, the
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`specification, and the prosecution history-the court's construction is a determination oflaw.
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`See Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831, 841 (2015). The court may also
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`make factual findings based upon consideration of extrinsic evidence, which "consists of all
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`evidence external to the patent and prosecution history, including expert and inventor testimony,
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`dictionaries, and learned treatises." Phillips, 415 F.3d at 1317-19 (internal quotation marks and
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`citations omitted). Extrinsic evidence may assist the court in understanding the underlying
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`technology, the meaning of terms to one skilled in the art, and how the invention works. Id
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`Extrinsic evidence, however, is less reliable and less useful in claim construction than the patent
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`and its prosecution history. Id.
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`"A claim construction is persuasive, not because it follows a certain rule, but because it
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`defines terms in the context of the whole patent." Renishaw PLC v. Marposs Societa 'per
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`Azioni, 158 F.3d 1243, 1250 (Fed. Cir. 1998). It follows that "a claim interpretation that would
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`exclude the inventor's device is rarely the correct interpretation." Osram GmbH v. Int 'l Trade
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`Comm 'n, 505 F.3d 1351, 1358 (Fed. Cir. 2007) (internal quotation marks and citation omitted).
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`Case 1:13-cv-01674-RGA Document 296 Filed 06/26/15 Page 4 of 8 PageID #: 6691
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`II.
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`CONSTRUCTION OF DISPUTED TERM
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`A.
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`The '832 Patent
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`Claim 1 of the '832 patent reads:
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`A film dosage composition comprising:
`a. A polymeric carrier matrix;
`b. A therapeutically effective amount ofbuprenorphine or a pharmaceutically
`acceptable salt thereof;
`c. A therapeutically effective amount of naloxone or a pharmaceutically
`acceptable salt thereof; and
`d. A buffer in an amount to provide a local pH for said composition of a value
`sufficient to optimize absorption of said buprenorphine, wherein said local pH is
`from about 3 to about 3.5 in the presence of saliva.
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`('832 Patent, Claim 1) (relevant term italicized).
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`1.
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`"buff er"
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`a.
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`Plaintiffs' proposed construction: "Buffer" as used in the claims has its
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`plain and ordinary meaning as used in the pharmaceutical sciences: "buffer" means one or more
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`components that function to help resist changes to pH when small amount of an acidic or basic
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`agent are added.
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`b.
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`Defendants' proposed construction: A combination of a weak acid and its
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`conjugate base present in the composition, the base being provided by one of its soluble salts, in
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`a sufficient amount to [provide a local pH for the composition sufficient to optimize absorption
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`of said buprenorphine wherein said local pH is about 3 to about 3. 5 in the presence of saliva in
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`the mouth, where local pH refers to the pH of the region of the carrier matrix immediately
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`surrounding the active agent as the matrix hydrates and/or dissolves, for example, in the mouth
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`of the user]
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`c.
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`Court's construction: a buffer is a component in the composition that
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`functions to resist changes to pH when an acid or base is added to the composition.
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`Case 1:13-cv-01674-RGA Document 296 Filed 06/26/15 Page 5 of 8 PageID #: 6692
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`The crux of this dispute is whether a buffer must include both a weak acid and a
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`conjugate base, or whether a buffer need only include one of a weak acid or a conjugate base. In
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`other words, whether a buffer must be a combination, or whether one or more components will
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`suffice.
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`Plaintiffs provide useful definitions from specialized dictionaries but appear to recite
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`from them selectively. Merriam-Webster's Medical Desk Dictionary, cited by Plaintiffs,
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`describes a buffer as "a substance or mixture of substances (as bicarbonates and some proteins in
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`biological fluids) that in solution tends to stabilize the hydrogen-ion concentration by
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`neutralizing within limits both acids and bases." (D.I. 239 at p. 2; D.I. 239-1 at 3). 1 Similarly,
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`Plaintiffs quote from the Oxford Dictionary of Biochemistry and Molecular Biology: "any
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`substance or mixture of substances that, when dissolved (usually in water), will maintain its
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`solution at approximately constant pH despite small additions of acid or base." (D.I. 239 at p. 2;
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`D.I. 239-2 at 5). The very next sentence of that definition, however, reads, "The commonest
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`examples are moderately strong solutions containing both a weak acid and its conjugate base (or
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`a weak base and its conjugate acid)." (D.I. 239-2 at 5). Defendants question the use of these
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`definitions as not coming from pharmaceutical references. (D.I. 243 at p. 3). Instead,
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`Defendants point to Remington's as an authority on pharmaceutical science. Remington's states:
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`"Buffers are used to maintain the pH of a medicinal at an optimal value. A buffer is a solution of
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`a weak acid and its conjugate base, the base being provided by one of its soluble salts." (D.I.
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`1 Notably, part of the definition for "buffer solution," the next entry in the same dictionary,
`appears to comport with Defendants' definition of"buffer": "a solution that usu[ ally] contains ...
`a weak acid (as carbonic acid) together with one of the salts of this acid . . . and that by its
`resistance to changes in hydrogen-ion concentration on the addition of acid or base is useful in
`many ... processes." (D.I. 239-1 at 3).
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`Case 1:13-cv-01674-RGA Document 296 Filed 06/26/15 Page 6 of 8 PageID #: 6693
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`245-1 at 12). Defendants argue that there is no compelling reason to deviate from what it
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`believes is the ordinary meaning of buffer. (D.I. 243 at p. 4).
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`Even though the definitions strongly suggest that a buffer often--or in its "commonest
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`example"-contains both a weak acid and a conjugate base, that does not appear to always be the
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`case. Instead, the fundamental characteristic of a buffer is that it buffers, or resists changes to,
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`pH. The definitions offered by the parties suggest that more often than not this is done with both
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`an acid and a base. But even so, the combination is not required. The Court's construction,
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`unlike Plaintiffs' proposal, makes clear that the buffer must function to resist changes to pH(cid:173)
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`not merely "help" resist changes. Similarly, Plaintiffs' inclusion of "small amounts" of an acid
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`or base does not add meaning to buff er.
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`The claims, as Plaintiffs argue, by themselves demonstrate buffer may refer to a single
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`component or combination. (D.I. 239 at p. 3). For example, claim 7 of the patent reads, "The
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`film dosage composition of claim 1, wherein said buffer comprises sodium citrate, citric acid,
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`and combinations thereof." ('832 Patent, Claim 7). The fact that the claim explicitly
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`contemplated "combinations" of sodium citrate and citric acid suggests that, by themselves,
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`sodium citrate and citric acid could act as the said buffer. If sodium citrate or citric acid could be
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`buffers by themselves, it would not be correct that a combination of components, as Defendants
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`assert, is required.
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`The specification also demonstrates that a buffer is not limited to a combination of an
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`acid and base. Plaintiffs argue that the specification states in several places that "any buffer"
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`may be used. (D.1. 239 at p. 4). Defendants argue that the examples in the patent that the buffer
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`"may include" or "comprise" sodium citrate, citric acid, or combinations do not demonstrate that
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`the buffer is citric acid or is sodium citrate. (D.1. 243 at p. 8; see, e.g, '832 Patent at 13:7-10
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`Case 1:13-cv-01674-RGA Document 296 Filed 06/26/15 Page 7 of 8 PageID #: 6694
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`("Any buffer system may be used as desired. In some embodiments, the buffer may include
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`sodium citrate, citric acid, and combinations thereof.")). Defendants overstate their claim. This
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`"include" or "comprise" language does not by itself demonstrate that a buffer is only citric acid
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`or sodium citrate. But the language does suggests that an expansive view of a buffer system was
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`contemplated to cover "any" buffer system. Similarly, as with the claim language, the fact that
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`the buffer could also include "combinations" of sodium citrate and citric acid suggests that it
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`could also include the components by themselves--else there would be no need to call out
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`combinations explicitly.
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`Defendants do point to persuasive examples in the specification, but it would be improper
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`to limit the claim language to these examples. Defendants argue that the specification
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`demonstrates that the invention functions by requiring both a weak acid and conjugate base.
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`(D.I. 243 at p.5; see '832 Patent, Table 5). For example, in describing three test film
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`formulations, the specification says that the "first film did not include any buffer," and in the
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`corresponding column of Table 5, that test film contains neither citric acid nor sodium nitrate.
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`('832 Patent at 18:37-38). In contrast, the two other test formulations are described as
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`"buffered" and contain a mix of citric acid and sodium citrate. (' 832 Patent at 18:38-40). More
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`specifically, Defendants point out that the claim specifies that the buffer provides a local pH
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`from about 3 to 3.5 in the presence of saliva and that the second test formulation of Table 5,
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`which has a "pH= 3-3.5," contains 2.96 mg of citric acid and 2.34 mg of sodium citrate. (D.I.
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`243 at p. 5; '832 Patent, Table 5). Defendants argue that this is consistent with the construction
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`of a buffer as a conjugate base and weak acid. (D.I. 243 at p. 6). Defendants are correct that this
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`is consistent with a construction of buffer that contains both a conjugate base and weak acid, but
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`Case 1:13-cv-01674-RGA Document 296 Filed 06/26/15 Page 8 of 8 PageID #: 6695
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`it does not prove anything. A combination of acid and base counts as a buffer, but that does not
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`foreclose an individual component, such as citric acid or sodium citrate, also being a buffer.
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`Both parties cite to the prosecution history and prior art cited in the patent to illuminate
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`the meaning of buffer, but the Court does not find this evidence particularly persuasive either
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`way. Plaintiffs have cited cases of other courts construing "buffering agent," but it is
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`challenging to draw much from constructions of this term within the context of entirely different
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`patents and intrinsic records. (D.I. 239 at p. 7).
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`For the above reasons, a buffer is a component in the composition that functions to resist
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`changes to pH when an acid or base is added to the composition.
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