MEMORANDUM OPINION

LEONARD P. STARK, District Judge.

Plaintiff Horatio Washington Depot Technologies, LLC ("Horatio") sued Defendants TOLMAR, Inc., TOLMAR Pharmaceuticals, Inc., and TOLMAR Therapeutics, Inc. (together, "Tolmar"), alleging that Tolmar infringes Horatio's U.S. Patent Nos. 5,932,547 ("the '547 patent"), 6,124,261 ("the '261 patent"), and 6,235,712 ("the '712 patent"). (D.I. 1) The patentsin-suit describe stable non-aqueous formulations that include a peptide and a polar aprotic solvent.1 (See '547 patent, Abstract) These formulations may be used, for example, to treat prostatic cancer. (`547 patent, 2:29-46)

Presently before the Court are the parties' disputes over the meaning of certain terms in the asserted claims. The parties submitted technology tutorials (D.I. 67, 68) and claim construction briefs (D.I. 62, 66, 70, 72). Tolmar also filed objections to Horatio's technology tutorial. (D.I. 69) The Court held a claim construction hearing on October 22, 2018. (D.I. 79 ("Tr."))

I. LEGAL STANDARDS

The ultimate question of the proper construction of a patent presents an issue of law. See Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S.Ct. 831, 837 (2015) (citing Markman v. Westview Instruments, Inc., 517 U.S. 370, 388-91 (1996)). "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. AWHCorp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (citation and internal quotation marks omitted). "[T]here is no magic formula or catechism for conducting claim construction." Id. at 1324. Instead, the court is free to attach the appropriate weight to appropriate sources "in light of the statutes and policies that inform patent law." Id.

"[T]he words of a claim are generally given their ordinary and customary meaning . . . [which is] the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention, i.e., as of the effective filing date of the patent application." Id. at 1312-13 (internal citations and quotation marks omitted). "[T]he ordinary meaning of a claim term is its meaning to the ordinary artisan after reading the entire patent." Id. at 1321 (internal quotation marks omitted). The patent "specification is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term." Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996).

While "the claims themselves provide substantial guidance as to the meaning of particular claim terms," the context of the surrounding words of the claim also must be considered. Phillips, 415 F.3d at 1314. Furthermore, "[ojther claims of the patent in question, both asserted and unasserted, can also be valuable sources of enlightenment . . . [bjecause claim terms are normally used consistently throughout the patent." Id. (internal citation omitted).

It is likewise true that "[differences among claims can also be a useful guide—For example, the presence of a dependent claim that adds a particular limitation gives rise to a presumption that the limitation in question is not present in the independent claim." Id. at 1314-15 (internal citation omitted). This "presumption is especially strong when the limitation in dispute is the only meaningful difference between an independent and dependent claim, and one party is urging that the limitation in the dependent claim should be read into the independent claim." SunRace Roots Enter. Co., Ltd. v. SRAM Corp., 336 F.3d 1298, 1303 (Fed. Cir. 2003).

It is also possible that "the specification may reveal a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess. In such cases, the inventor's lexicography governs." Phillips, 415 F.3d at 1316. It bears emphasis that "[e]ven when the specification describes only a single embodiment, the claims of the patent will not be read restrictively unless the patentee has demonstrated a clear intention to limit the claim scope using words or expressions of manifest exclusion or restriction." Hill-Rom Servs., Inc. v. Stryker Corp., 755 F.3d 1367, 1372 (Fed. Cir. 2014) (internal quotation marks omitted).

In addition to the specification, a court "should also consider the patent's prosecution history, if it is in evidence." Markman v. Westview Instruments, Inc., 52 F.3d 967, 980 (Fed. Cir. 1995), aff'd, 517 U.S. 370 (1996). The prosecution history, which is "intrinsic evidence," "consists of the complete record of the proceedings before the [Patent and Trademark Office] and includes the prior art cited during the examination of the patent." Phillips, 415 F.3d at 1317. "[T]he prosecution history can often inform the meaning of the claim language by demonstrating how the inventor understood the invention and whether the inventor limited the invention in the course of prosecution, making the claim scope narrower than it would otherwise be." Id

"In some cases, . . . the district court will need to look beyond the patent's intrinsic evidence and to consult extrinsic evidence in order to understand, for example, the background science or the meaning of a term in the relevant art during the relevant time period." Teva, 135 S. Ct. at 841. "Extrinsic evidence consists of all evidence external to the patent and prosecution history, including expert and inventor testimony, dictionaries, and learned treatises." Markman, 52 F.3d at 980. For instance, technical dictionaries can assist the court in determining the meaning of a term to those of skill in the relevant art because such dictionaries "endeavor to collect the accepted meanings of terms used in various fields of science and technology." Phillips, 415 F.3d at 1318. In addition, expert testimony can be useful "to ensure that the court's understanding of the technical aspects of the patent is consistent with that of a person of skill in the art, or to establish that a particular term in the patent or the prior art has a particular meaning in the pertinent field." Id. Nonetheless, courts must not lose sight of the fact that "expert reports and testimony [are] generated at the time of and for the purpose of litigation and thus can suffer from bias that is not present in intrinsic evidence." Id Overall, while extrinsic evidence "may be useful to the court," it is "less reliable" than intrinsic evidence, and its consideration "is unlikely to result in a reliable interpretation of patent claim scope unless considered in the context of the intrinsic evidence." Id at 1318-19. Where the intrinsic record unambiguously describes the scope of the patented invention, reliance on any extrinsic evidence is improper. See Pitney Bowes, Inc. v. Hewlett-Packard Co., 182 F.3d 1298, 1308 (Fed. Cir. 1999).

Finally, "[t]he construction that stays true to the claim language and most naturally aligns with the patent's description of the invention will be, in the end, the correct construction." Renishaw PLC v. Marposs Societa'per Azioni, 158 F.3d 1243, 1250 (Fed. Cir. 1998). It follows that "a claim interpretation that would exclude the inventor's device is rarely the correct interpretation." Osram GmbH v. Int'l Trade Comm'n, 505 F.3d 1351, 1358 (Fed. Cir. 2007) (internal quotation marks omitted).

II. CONSTRUCTION OF DISPUTED TERMS2

All three patents-in-suit are entitled "Non-Aqueous Polar Aprotic Peptide Formulations." The asserted claims relate to "stable non-aqueous formulation[s]" comprising a "peptide compound," such as luteinizing hormone-releasing hormone (LHRH), and a "polar aprotic solvent," methods for preparing these formulations, and methods for treating prostatic cancer using these formulations. (`547 patent, cl. 1; '261 patent, cl. 3, 4; '712 patent, cl. 1, 8) According to the specification, using non-aqueous polar aprotic solvents results in more physically and chemically stable peptide formulations than "standard" formulations, which "consist of dilute aqueous solutions." (`547 patent, 4:14-36) The specification states that this increased stability "mak[es] possible the delivery of peptides in long term implantable devices that would not otherwise be feasible." (`547 patent, 4:48-56)

A. "[stable] non-aqueous formulation"3

The parties agree that "stable" is expressly defined in the specification (see '547 patent, 3:12-13, 5:4-7) and agree that the use of the term in the preamble is limiting, but they disagree as to the meaning of "non-aqueous formulation." (See D.I. 62 at 14; D.I. 66 at 3) The dispute centers on whether a "formulation" can be, as Horatio contends, a depot, suspension, or dispersion or whether, as Tolmar contends, a "formulation" must be a solution. (D.I. 62 at 14-15; D.I. 72 at 2)

The Court will adopt Tolmar's construction because the specification repeatedly and consistently characterizes the claimed formulation as a solution. "[W]hen a patent `repeatedly and consistently' characterizes a claim term in a particular way, it is proper to construe the claim term in accordance with that characterization." GPNE Corp. v. Apple Inc., 830 F.3d 1365, 1370 (Fed. Cir. 2016) (internal citations omitted). Here, for example, the patent states:

The specification describes the invention as "drawn to the unexpected discovery that dissolving peptide compounds in non-aqueous polar aprotic solvents results in stable formulations," and discloses observations of the stability of more than a dozen solutions, but never suggests that the discovered stabilizing effect would be present in depots or suspensions. (See generally '547 patent, 4:14-56, 5:55-8:42, 7:1-34)

Horatio is correct that a characterization may not be limiting "where the references to [the] limitation as being the `invention' are not uniform, or where other portions of the intrinsic evidence do not support applying the limitation to the entire patent." (D.I. 72 at 3) (quoting Absolute Software, Inc. v. Stealth Signal, Inc., 659 F.3d 1121, 1136 (Fed. Cir. 2011)) But Horatio fails to identify any evidence that supports its reading of the claimed formulations to include depots, suspensions, or dispersions. Nor does Horatio point to any intrinsic evidence suggesting that a claimed formulation would be "stable" if it was not a solution. Contrary to Horatio's contentions (see D.I. 72 at 3-4), the specification's use of the word "formulation" to describe the invention does not, in itself, broaden the meaning of the term "formulation" in the phrase "stable non-aqueous formulation." As Tolmar correctly notes (D.I. 70 at 16), while "formulation" is sometimes used in the patents to refer to depots and suspensions, the patents only characterize the inventive "stable non-aqueous formulation" as a solution.

B. "leuprolide," "LHRH," nafarelin," and "goserelin4

The parties disagree as to whether each of four peptides recited in the claims, "leuprolide," "LHRH," "nafarelin," and "goserelin" (together, "the recited peptides"), should be construed to include just the respective peptide itself, or also to include other peptides that are related in function and/or structure. (D.I. 62 at 10-12; D.I. 66 at 6-7)

Tolmar's constructions reflect the plain and ordinary meaning of the respective peptides. See Poly-Am, LP. v. API Indus., Inc., 839 F.3d 1131, 1136 (Fed. Cir. 2016) (stating that construction should depart from plain and ordinary meaning only when patentee acts as lexicographer or disavows claim scope during prosecution). The asserted patents do not explicitly define any of the recited peptides, and the patentee did not disavow the scope of the recited peptides during prosecution.

Horatio contends that "at least four times" the patents "broadly describe" the recited peptides as including salts of those peptides. (D.I. 66 at 6-7) None of the passages cited by Horatio defines any of the recited peptides. (`547 patent, 5:13-29, 6:1-21) Rather, these passages define the terms "peptide," "peptide compound," and "LHRH-related compound," provide examples of "peptides" and "peptide compounds," and state that "peptide compounds" can be used in the form of salts. (Id.) That the recited peptides are peptide compounds and LHRH-related compounds does not necessarily extend all characteristics of "peptides," "peptide compounds," and "LHRH-related compounds" to the specific, recited peptides.

Claim differentiation, which creates a "presumption that each claim in a patent has a different scope," AllVoice Computing PLC v. Nuance Communications, Inc., 504 F.3d 1236, 1248 (Fed. Cir. 2007), further undermines Horatio's construction. For example, claim 1 of the `547 patent recites a "peptide compound . . . wherein said peptide compound is an LHRH-related compound." Claim 4 of the '547 patent claims "[t]he formulation of claim 1 wherein said peptide compound is selected from the group consisting of leuprolide, LHRH, nafarelin and goserelin." The patent defines LHRH-related compound as follows:

(`547 patent, 5:22-29) All of the recited peptides are LHRH agonists. Horatio's construction of each recited peptide includes not only the peptide itself but also all analogs, agonists, antagonists, and salts. Thus, under Horatio's construction, claim 4 of the '547 patent is essentially coterminous with claim 1 of that patent. For the same reasons, under Horatio's construction, claim 4 of the '712 patent is essentially coterminous with claim 1 of that patent.

C. "dissolving"5

The parties' constructions of "dissolving" follow from their competing constructions of "formulation." Horatio contends that a "formulation" can be a solution, depot, dispersion, or suspension (D.I. 62 at 14-15), so it construes "dissolving" to include mixing together to form a mixture or suspension (id. at 7-9). Tolmar contends that a "formulation" can only be a solution (D.I. 62 at 14-16), and so construes "dissolving" with respect only to forming a solution, that is, a single-phase homogenous mixture. (D.I. 62 at 16-19)

The Court's construction of "dissolving" — "mixing together to form a solution" — follows from its construction of "formulation." As explained above, the claimed formulations are solutions. Thus, because claim 1 of the '712 patent recites "preparing a . . . formulation" by "dissolving" an "LHRH-related peptide compound" in a "polar aprotic solvent," the step of "dissolving" creates a solution.

Horatio contends that because the patents describe formulations as variously being "suspensions," "solutions," "mixtures," and attempted solutions, the term "dissolving" should not be limited solely to solutions. (D.I. 66 at 8; D.I. 72 at 8-9) But the suspensions described by the patents as formulations are prior art, not the claimed invention. (See '547 patent, 2:64-3:6)

D. "LHRH antagonist"7

Horatio contends that the use of "LHRH antagonist" in the claims is a mistake made in prosecution that the Court should correct. (D.I. 66 at 9-14; D.I. 72 at 10-11) In its briefing, Horatio argued that its correction satisfies the two-part test laid out in Novo Indus., L.P. v. Micro Molds Corp., 350 F.3d 1348, 1354 (Fed. Cir. 2003). (D.I. 66 at 9-14) However, during the Markman hearing, Horatio contended that the Novo test does not apply here because the asserted patents are expired and therefore, unlike the patent in Novo, cannot be corrected by the Patent Office. (Tr. at 43-45) Horatio now insists that Phillips is the appropriate standard under which to interpret the claims. (Tr. at 45) In the alternative, Horatio maintains its original argument that the Court should correct the claim term under Novo. (Id.)

Horatio does not cite any authority for its proposition that the Novo test does not apply to expired patents. (Id.) Nor does Horatio cite authority establishing that the PTO will not correct an expired patent that is being litigated.8 In any case, even were the Court were to apply Phillips, the Court is not persuaded that one of skill in the art would construe "LHRH antagonist" in the way Horatio suggests. The record does not consistently make clear whether LHRH is an agonist or antagonist; a POSA might find the claim indefinite

Generally — and here — a district court may only correct an "obvious minor typographical [or] clerical" error in a patent if (1) "the correction is not subject to reasonable debate based on consideration of the claim language and the specification" and (2) "the prosecution history does not suggest a different interpretation of the claims." Novo, 350 F.3d at 1354. Horatio's proposed correction of "LHRH antagonist" is not proper because its appropriateness would be subject to reasonable debate. It is true, as Horatio contends, that as a result of the mistake, claims 12 and 13 are "nonsensical" because they characterize leuprolide, an LHRH agonist, as an "LHRH antagonist." (D.I. 66 at 12) But, as Tolmar points out (D.I. 70 at 9), there are multiple possible reasonable corrections: "LHRH antagonist" could be interpreted as "LHRH agonist" or "LHRH analog." Both of these alternative constructions would also fix the scientific inaccuracy that exists in claims 12 and 13 as written, as even Horatio seems to acknowledge. (See Tr. at 49-50) ("[A] correction of LHRH antagonist' to `LHRH agonist' would also remedy [the purported] error and bring claims 8 to 10 and 12 to 15 into agreement.")

The Court is not persuaded that anything in Tolmar's construction of "LHRH-antagonisf prevents "LHRH-agonist" from being construed in a scientifically accurate manner. Accordingly, the Court will largely adopt Tolmar's construction, which is a scientifically accurate definition of an LHRH antagonist. However, the Court will clarify in its construction that an LHRH antagonist's inhibitory effect occurs "after initial administration."

E. "implantable drug delivery device" and "implantable drug delivery system"9

Horatio contends that these terms cover both pre-formed device/system injections and in situ depot injections. (D.I. 66 at 14-15) Tolmar counters that the terms cover only pre-formed device/system injections. (D.I. 62 at 19-20)

The Court agrees with Horatio that in situ depot injections are within the plain meaning of the terms "implantable drug delivery device" and "implantable drug delivery system." The intrinsic evidence does not disturb this interpretation. Tolmar points out that the patents provide several examples of "implantable devices," all of which are pre-formed. (See DJ. 62 at 19-20) (citing '547 patent, 8:61-67, 2:47-53) Tolmar also notes that the patents criticize prior art depot formulations. (D.I. 70 at 19-20) But excluding depot injections from the construction is not supported because the patents do not show a "clear intention" by the patentee, using words of "manifest exclusion or restriction," to limit "implantable drug delivery device" and "implantable drug delivery system" solely to pre-formed devices and systems. See Hill-Rom, 755 F.3d at 1372. Nothing in the patents suggests that a depot is not an "implantable device" nor that the inventive stable non-aqueous formulations could not be delivered by a depot.

F. "leuprolide is administered daily"10

The parties disputed the construction of "leuprolide is administered daily" in their claim construction briefing (D.I. 62, 66, 70, 72) but now agree that the term should be given its plain and ordinary meaning (D.I. 75). The Court will adopt this construction.

III. CONCLUSION

The Court will construe the disputed terms as explained above. An appropriate Order follows.