# United States **Court of Appeals**  **for the Federal Circuit**

______________________

TAKEDA PHARMACEUTICA L COMPANY LIMITED, TAKEDA PHARMACEUTICA LS NORTH

AMERICA, INC., TAKEDA PHARMACEUTICA LS, LLC, TAKEDA PHARMACEUTICALS AMERICA, INC., AND ETHYPHARM, S.A., Plaintiffs

- Appellees,

v.

ZYDUS PHARMACEUTICAL S USA, INC. AND CADILA HEALTHCARE LI MITED, Defendants

- Appellants.

______________________

2013

- 1406

______________________ Appeal from the Unit ed States District Court for the District of New Jersey in No. 10

- CV

- 1723, Judge Joel A. Pisano.

______________________

Decided: February 20, 2014

______________________

A RLENE L. C HOW , Hogan Lovells US LLP, of New York, New York, argued for plaintiffs

- appellees. With h er on the brief were E RIC J. L OBENFELD of New Y ork, New York ; C ATHERINE E. S TETSON and F REDERICK L IU , of Washington, DC. Of counsel was P HILIPPE Y OLAND R IESEN , of Tokyo, Japan.TAKEDA PHARMACEUTICAL CO

. v. ZYDUS PHARMACEUTICAL S
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S TEVEN J. M OORE , Kelley Drye & Warren, LLP, of Stamford, Connecticut, argued for defendants

- appellants. With him on the brief was J AMES E. N EALON

.

______________________

Before P ROST , P LAGER , and C HEN , Circuit Judges.

P ROST , Circuit Judge

. Zydus Pharmaceuticals USA, Inc. and Cadila Healthcare Limited (“appellants” or “Zydus”) appeal f rom a final judgment of the U.S. District Court for the District of New Jersey finding that appellants had infringed claim 1 of U.S. Patent No. 6,328,994 (“’994 patent”) and had failed to establish that it was invalid. For the reasons stated below, we reverse the district court’s finding of infringement, but affirm its ruling on invalidity.

B ACKGROUND Takeda Pharmaceutical Company Limited, Takeda Pharmaceuticals North America, Inc., Takeda Pharm aceutica ls, LLC, Takeda Pharmaceuticals America, Inc.

, and Ethypharm, S.A. (“appellees” or “Takeda” ) own patents that claim the formulation for the brand

- name drug Prevacid® SoluTabTM. Prevacid® SoluTabTM co ntains the active ingredient lansoprazole, which is a proton pump inhibitor used to treat gastroesopha geal reflu x disease , or acid reflux

. It is the only proton pump inhib itor available as an orally disintegrable tablet . A patient taking Prevacid® SoluTabTM simply allows the tablet to disinte grate in his o r her mouth, leaving behind tho usands of granules which the patient then swallows. The stated objective of the ’994 patent is that the formulation contains granules small enough to avoid a feeling of roughness in the patient’s mouth upon disintegration

. In 2010, Zydus filed an abbreviated new drug applic ation (“ANDA”) with the Food and Drug Administ ration

, seeking to manufacture a generic version of Prevacid®TAKEDA PHARMACEUTICAL CO

. v. ZYDUS PHARMACEUTICALS
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SoluTabTM. Takeda then filed suit , alleging that Zydus’ s ANDA product infringed multiple claims of several p atents. Only claim 1 of the ’994 patent remains at issue. Zydus counterclaimed , alleging that claim 1 was invalid for failure to comply with the requirements of 35 U.S.C. § 112.

Claim 1 recites:
An orally disintegrable tablet which comprise s (i) fine granules having an average particle diameter of 400 μ m or less, which fine granules comprise a composition coated by an enteric coating layer comprising a first component which is an enteric coating agent and a second component which is a sustai ned

- release agent, said composition having 10 weight % or more of an acid

- labile physiolog ically active substrate that is lansoprazole and (ii) an additive wherein said tablet having a hardness strength of about 1 to about 20 kg, is orally disi ntegrable.

’ 994 patent col. 37 ll. 43

- 53. T he district court held a claim construction hearing, at which it construed the claim term “fine granules having an average particle diameter of 400 μ m or less .” Takeda argued that the term should be construed to include a d eviation of ±10% , b ecause it i s “universally accepted” that there is a 10% standard of error for particle size measurements. J.A. 154. Zydus, on the other hand, argued that the term should be construed as “precisely 400 μm.” J.A. 496. The district court agreed with Takeda, and construed the term
to mean “fine granules up to and including the enteric coating layer having an average particle diameter of 400 μm (±10%) or less.” Takeda Pharm. Co. v. Zydus Pharms. USA Inc.

, No. 10

- 1723, 2 011 WL 4736306, at * 3- 4 (D.N.J. Oct. 5, 2011).
The issue of infringement turned on how particle size

wa s measured. During the manufacturing process, ind i-TAKEDA PHARMACEUTICAL CO

. v. ZYDUS PHARMACEUTICAL S
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vidual cores of lansoprazole are enteric coated using a fluid

- bed coating process. Inevitably, tha t process results in a certain portion of the coated cores becoming fused together. These fused multi

- cored granules are known as “hard a gglomerates .”
Takeda argued that the average particle diameter should be determined by measuring each individual cor e, regardless of whether they had fused together into a hard agglomerate. Taking that measurement require s “virtual dissection” of hard agglomerates, meaning drawing an artificial line between the two fused cores such that the software will treat them separately for measurement purposes. Obviously, artificially dividing large hard agglomerates into several smaller granules for measur ement purposes lowers the average particle size of a sa mple, making it more likely to infringe claim 1 of the ’994 patent

. Zydus argued that, to the contrary, because the specification describes measuring particle size after the coating process and says nothing about deagglomeration, it by definition includes hard agglomerates in the mea surement of average particle diameter

. In support of its position, Zyd us pointed out that the actual size of the fused particles is what is relevant to how the granules feel in the patient’s mouth, regardless of the size of the smal ler fused cores that make up a hard agglomerate. Under the district court’s claim construction, where the max imum average particle size is 440 μm, Zydus’s ANDA product would infringe claim 1 of the ’994 patent if hard agglomerates were virtually dissected prior to measur ement, but would not infringe if hard agglom erates were included in the measurement.
After a bench trial, the district court agreed with Takeda and found that the ’994 patent requires measu ring the average diameter of each core , regardless of how many cores are in a given hard agglomerate. Takeda Pharm. Co.

, Ltd. v. Zydus Pharms. USA Inc.

, No. 10

- 1723

, slip op. at 12

- 13 (D.N.J. May 7

, 2013) (“ Opinion ”)

. BasedTAKEDA PHARMACEUTICAL CO

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on that finding , the district court determined that Zydus’ s ANDA product infringed claim 1 of the ’994 patent

. Id. at 19

- 21. The district court further concluded that Zydus had failed to establish by clear and convincing evidence that claim 1 was invalid. Id. at 25

- 42. The court then entered an injunction preventing Zydus from manufactu ring or selling its ANDA product until the expiration of the ’994 patent. Id. at 43

- 46. Zydus appealed all of the district court’s rulings.
We have jurisdiction under 28 U.S.C. § 1295(a)(1).

A NALYSIS

I. Claim Construction
Claim construction is a question of law that we review without deference. Cybor Corp. v. FAS Techs., Inc. , 138 F.3d 1448, 1455

- 56 (Fed. Cir. 1998) (en banc). Our star ting point in construing a claim term must be the words of the claim itself. See Vitronics Corp. v. Conceptronic, Inc.

, 90 F.3d 1576, 1582 (Fed. Cir. 1996); Phillips v . AWH Corp. , 415 F.3d 1303, 1314 (Fed. Cir. 2005) (en banc) (“[T]he claims themselves provide substantial guidance as to the meaning of particular claim terms.”). However, it is axiomatic that the claims “must be read in view of the specification, of whic h they are a part.” Phillips , 415 F.3d at 1315 (quoting Markman v. Westview Instruments, Inc.

, 52 F.3d 967, 979 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370 (1996) ). Additionally, a court “should also consider the patent’s prosecution history, if it is in evidence.” Markman , 52 F.3d at 980. Although courts are permitted to consider extrinsic evidence, such as expert testimony, dictionaries, and treatises, we have cautioned that such evidence is generally of less significance than the intrinsic record. Phillips , 415 F.3d at 1317 (citing C.R. Bard, Inc. v. U.S. Surgical Corp. , 388 F.3d 858, 862 (Fed. Cir. 2004)). Ultimately, “[t]he construction that stays true to the claim language and most naturally aligns with the p atent’ s description of the inventio n will be, in the end, theTAKEDA PHARMACEUTICAL CO

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correct construction.” Renishaw PLC v. Marposs Societa’ per Azioni , 158 F.3d 1243, 1250 (Fed. Cir. 1998).
With these principles in mind, we turn to the disputed claim language. Zydus challenges the district court’s constructi on of the claim term “fine granules having an average particle diameter of 400 μm or less.” The district court construed that term to include a ±10% deviation. Zydus argues that it should be construed to require an average particle diameter of “ precisely 400 μm or less.” We agree with Zydus that the district court erred in reading a margin of error into the disputed claim term.
Beginning with the claim language itself

— as we must

— there is no indication in the claim that 400 μm was intended to mean anyth ing other than exactly 400 μm. To the contrary, the phrase “400 μm or less” is not qualified by the word “about” or any other indicator of imprecision.
Moreover, the specification confirms that the inve ntors did not intend to deviate from that clear and una mbiguous plain meaning. First, the specification contrasts the “fine granules” of the claimed invention with larger “conventional” granules, which it defines as “400 μm or more of average particle diameter.” ’994 patent col. 2 ll. 17

- 18. The specifi cation explains that conventional granules of that size “produce a feeling of roughness in the mouth”

— one of the very problems the claimed inve ntion purports to solve. Id. col. 2 ll. 16

- 17. That clear dividing line between the “fine” granules of 400 μm or less (which avoid a feeling of roughness in the mouth) and “conventional” granules of 400 μm or more (which do not) disappears if the “fine granules” are construed as incorp orating a 10% deviation. Thus, there can be little doubt that the narrower cons truction “most naturally aligns with the patent’s description of the invention.” Renishaw

, 158 F.3d at 1250.
Second, the specification goes on to explain that the maximum particle size is “practically 425 μm or less,”TAKEDA PHARMACEUTICAL CO

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where “practically” means that “the particles may include a small quantity (about 5 weight % or less) of particles whose particle diameter is out of above described range.” ’994 patent col. 5 l. 65

– col. 6 l. 8. Elsewhere, t he patent defines “average particle diameter” to mean the median p article diameter

. S ee id. col. 5 ll. 43

- 46

. I t would be impossible for a tablet to comply with the specific ation’s maximum particle diameter of practically 425 μm (meaning that only 5% of particles have diameters larger than 425 μm) if it had a median pa rticle diameter of 440 μm (meaning that 50% of the particles are larger than 440 μm), as the district court’s claim construction would permit. T his tension suggests that the inventors did not intend to incorporate a ±10% deviation into the average particl e diameter of claim 1.
Takeda argues that the inventors effectively acted as their own lexicographers and modified the plain meaning of the term “fine granules” in the specification. The specification states:
In the present invention, “fine granules ha ving an average particle diameter of 400 μm or less, which fine granules comprise a composition coated by an enteric coating layer, said composition having 10 weight % or more of an acid

- labile physiologically active substance” have an average particle dia meter of about 400 μm or less, in order that roug hness is not felt in the mouth. Preferably, the average particle diameter of the fine granules is 300 to 400 μm.
’994 patent col. 5 ll. 57

- 64 (emphasis added). Takeda maintain s that the inventors therefor e expressly defined 400 μm as an approximate figure, and that a skilled artisan would know that a standard deviation for particle

size measurements is ±10%. We disagree.
The word “about” is used to modify the phrase “400 μm or less” only three times in th e specification. InTAKEDA PHARMACEUTICAL CO

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addition to the passage quoted above, the specification
states: [T]he average particle a [sic] diameter of the i ncluded granules must be about 400 μm or less, preferably about 350 μm.

Id. col. 2 ll. 20

- 22. And later, it reiterates:

T he “fine granules” have an average particle d iameter of about 400 μm or less, preferably 350 μm or less. Preferably; the average particle diameter of the fine granules is 300 to 400 μm.

Id. col. 12 ll. 58

- 61. In every one of these instances, the word “a bout” is immediately followed by a preference for an average particle size lower than 400 μm. Nowhere does the specification suggest that an average particle size greater than 400 μm (even within 10% of that figure) could achieve the inventive result of avoiding a feeling of roughness in the mouth. Thus, we are not persuaded that the mere presence of the word “about” at three points in the specification can justify a 10% expansion of claim

scope. Indeed, the remainder of claim 1 demonstrates that the in ventors knew how to express ambiguity in claim language when they so desired; it provides that the tablet must have a hardness strength of “ about 1 to about 20 kg.” ’994 patent col. 37 l. 52 (emphasis added). Plainly, then, had the inventors desired the average particle diameter to include a margin of error, they could easily have included the word “about” in the claim language. In the absence of their decision to do so, however, we will not take it upon ourselves to rewrite the claim in that way.

This r eading of the specification is confirmed by the prosecution history. There, the inventors distinguished the claimed invention over a potentially invalidating prior art reference because the reference failed to disclose an average particle di ameter of 400 μm or less. J.A. 7228.TAKEDA PHARMACEUTICAL CO

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The inventors explained that “[b]y having the average particle diameter of the granules within 400 μm, the feeling of roughness in a mouth can be prevented.” J.A. 7228 (emphasis added). In other words, the inventors have consistently relied on 400 μm as the dividing line between granules that would avoid roughness in the mouth and those that would not

— meaning those that were within the scope of the invention, and those that were not. We long ago established that “[w]here there is an equal choice between a broader and a narrower mea ning of a claim, and there is an enabling disclosure that indicates that the applicant is at least entitled to a claim having the narrower m eaning, we consider the notice function of the claim to be best served by adopting the narrower meaning.” Athletic Alternatives, Inc. v. Prince Mfg., Inc. , 73 F.3d 1573, 1581 (Fed. Cir. 1996). Thus,

e ven if the two proposed constructions before us presen ted an “equal choice”

— and they do not

— the narrower co nstruction would be more appropriate.

We therefore reverse the district court’s claim co nstruction and conclude that the proper construction of the disputed claim term is “fine granules having an averag e particle diameter of precisely 400 μm or less.”

II. Infringement
As explained above, the dispute as to literal infring ement turned on whether the patent required virtual dissection of hard agglomerates prior to particle size
measurement. Even u sing virtual dissection, however, Takeda measured Zydus’s ANDA product as having an average particle diameter of 412.28 μm

— well outside the claimed range as we have now construed it

. Appellants’ Br. 31; J.A. 8338. Thus, there can be no dispute thatTAKEDA PHARMACEUTICAL CO

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Zydus ’s ANDA product does not literally infringe claim 1 of the ’994 patent. 1
We therefore reverse the district court’s finding of li teral infringement.

III. Invalidity
Zydus raises several challenges to the validity of the ’994 patent based on a failure to satisfy the requir ements of 35 U.S.C. § 112. A number of those arguments related to the claim construction adopted by the district court, which we have now reversed, and are therefore moot. We will address the remaining arguments in turn.

A. Indefiniten ess
We review a district court’s ruling on indefiniteness de novo, as it is a question of law. ePlus, Inc. v. Lawson Software, Inc. , 700 F.3d 509, 516 (Fed. Cir. 2012). “Whether a claim is invalid for indefiniteness requires a determination whether thos e skilled in the art would understand what is claimed when the claim is read in light of the specification.” Morton Int’l, Inc. v. Cardinal Chem. Co. , 5 F.3d 1464, 1470 (Fed. Cir. 1993). As always,
t he party challenging the patent bears the burden of proving invalidity by clear and convincing evidence. Microsoft Corp. v. i4i Ltd. P’ship , 131 S. Ct. 2238, 2242 (2011).
Zydus argues that the ’994 patent is indefinite b ecause it does not specify the method of measurement that

1 Although it was not necessary for us to consider whether the ’994 patent requires deagglomeration in our infringement analysis, we do consider that question below in the context of Zydus’s invalidity arguments. See infra Section III.C

.TAKEDA PHARMACEUTICAL CO

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should be used to determine average particle diameter. 2 Zydus insists that there are several methods that could potentially be used to take that measurement, and the same sample could be either infringing or non

- infringing depending on the measurement technique used. Thus, the skilled artisan has no way to determine whether his or her product infringes the ’994 patent based on the information provided in the specification.
We disagree. It is true that there was evidence from both parties’ experts that there are several possible ways to measure average particle diameter. Indeed, the patent specification itself identifies laser diffraction as just one “example” of such a measurement technique, ’994 patent col. 5 ll. 46

- 50, and the experts agreed that optical micro scopy is another equally viable method. Additionally, the experts agreed that different measurement techniques could indeed produce different results. The variation arises from the difficulty in measuring the average dia meter of particles that are not perfect spheres. By necess ity, b oth techniques involv e indirect measurements; laser diffraction involves analyzing the diffraction patterns of a laser beam passed through a field of particles, while optical microscopy involv es equating a pixelated image with an equivalent spherical diameter. See J.A. 3733

- 34, 3736

- 37. Because the two methods use different me ans of approximating average particle diameter, they can pr oduce different results even for the same sample.

However

, we do not believe that the mere possibility of different results from different measurement tec h2 Zydus actually argued that this fact rendered the claim invalid for lack of enablement. However, in support of its argument Zydus cited the legal standard for indefiniteness and re lied on cases applying that same standard. We have therefore con strued Zydus’s argument to be one of indefiniteness, rather than enablement.TAKEDA PHARMACEUTICAL CO

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niques renders claim 1 indefinite. Rather, the evidence established that both methods of measurement accurately report average particle diameter; the experts agreed that “the correct but differing particle size results obtained using various instruments are all equally correct, but each simply may be expressing its correct results in different terms.” J.A. 3983 (testimony of Zydus’s expert Dr. Harry Brittain) ; see also J.A. 4148

- 49 (testimony of Takeda’s expert Dr. Ste phen Byrn).
Moreover, there is no evidence that the differences b etween these tech niques are in fact signifi cant; the re was evidence before the trial court that although the results

may be diff erent, there is a “high degree of correlation for the results” between the two techniques, which should “give equivalent numbers with respect to any variants associated with either technique.” See J.A. 3738, 3792. And indeed, there was no evidence in thi s case that diffe rent measurement techniques in fact produced significan tly different results for the same sample. To the contrary, the measurements of Zydus’s ANDA product using laser diffraction and optical microscopy, though not exactly the

same, were substantially similar. Compare J.A. 8338 with J.A. 2115

. Any theoretical minor differences between the two techniques are therefore insufficient to render the patent invalid. See PPG Indus., Inc. v. Guar dian Indus. Corp. , 75 F.3d 1558, 1563 (Fed. Cir. 1996) (finding no in definiteness despite failure to specify which method should be used to measure ultraviolet transmi ttance because all conventional methods produced “esse ntially identical results”). 3

3 Indeed, the evidence showed that four samples of Zydus’s ANDA product, each measured using optical microscopy, produced average particle diameters of 457.1

μm , 446.5 μm , 443.4 μm , and 444.0 μm

. Appellants’ Br. 31; J.A. 8338. Plainly, then, there is the potential forTAKEDA PHARMACEUTICAL CO

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Amgen Inc. v. Hoechst Marion Roussel, Inc. , 314 F.3d 1313 (Fed. Cir. 2003) , on which Zydus relies, does not compel a contrary result

. Amgen involved patents rela ting to the production of erythropoietin, a naturally occu rring hormone that controls the formation of red blood cells in bon e marrow. One of the disputed claims related to an erythropoietin glycoprotein product “having glycosylation which differs from that of human urinary erythropoietin,” or uEPO. Id. at 1340. However, the district court had found that “two uEPO preparations produced from the same batch of starting materials could nevertheless have different glycosylation patterns.” Id. at 1341. Thus, the claim itself was a moving target; as we explained, “one must know what the glycosylation of uEPO is with ce rtainty befo re one can determine whether the claimed glycoprotein has a glycosylation different from that of uEPO.” Id. (emphasis added) . We therefore affirmed the district court’s finding that the claims requiring “glycosy lation which differs” were invalid for inde finiteness. Id. at 1342. That is a far cry from this case. Here, the claim term itself could not be more straightforward ; as we ruled above

, the claim plainly requires an average particle diameter of 400 μ m or less. That there i s more than one way of d etermining the average particle diameter of a particular sample does not render that clear claim la nguage indefinite. 4

inconsistent results even within the same method of measurement, but that surely does not render a claim indefinite.

4 Honeywell I nternational , Inc. v. International Trade Comm ission , 341 F.3d 1332 (Fed. Cir. 2003), is no more persuasive. There, the patent

- in

- suit related to the production of a polyester yarn product. Because the specification did not discuss which sample preparation metho d should be used, and the particular method chosenTAKEDA PHARMACEUTICAL CO

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Therefore, we conclude that Zydus has not met its burden of establishing by clear and convincing evidence that claim 1 of the ’994 pate nt is invalid for indefinit eness.
B. Written Description
The test for written description is “whether the discl osure of the application . . . reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date.” Ariad Pharms., Inc. v. Eli Lilly & Co. , 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc). The question of whether a patent specification contains sufficient written description is a question of fact that we review for clear error. Poz en Inc. v. Par Pharm., Inc. , 696 F.3d 1151, 1166 (Fed. Cir. 2012).
Zydus argues that claim 1 addresses average particle size in the finished tablet, while the specification only teaches how to measure particle size pre

- tableting with no discussion of how to ensure particle size is not altered by that process. Thus, Zydus argues that the specification does not demonstrate that the inventors were in posse ssion of the claimed invention

— tablets with particles of 400 μm or less post

- tableting.
However, Zydus’s argument depends on there actually being an impact on particle si ze from the tableting pr ocess, and the evidence showed the opposite. Indeed, actual testing conducted by Takeda’s expert showed no

was “critical to discerning whether [an infringing yar n] has been produced by the claimed process,” we affirmed the Commission’s conclusion that the claims were indefinite. Id. at 1340. Here, by contrast, no extensive manip ulat ion of the samples is required prior to measurement, and, as discussed above, Zydus did not present clear and convincing evidence that the method of measurement is in fact outcome

- determinative in the infringement analysis.TAKEDA PHARMACEUTICAL CO

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effect from compression forces on the granules in Zydus’s ANDA product. J.A. 3756

- 57, 3872

- 73. This case is therefore dist inguishable from Eli Lilly & Co. v. Teva Pharmaceuticals USA, Inc. , 619 F.3d 1329 (Fed. Cir. 2010), on which Zydus relies. There, we upheld a finding of invalidity where the invention related to particle size of a formulated drug but the specification only disclosed how to measure particle size pre

- formulation. Id. at 1345. However, the evidence in that case demonstrated that the particle size of Teva’s product fell outside the claimed range before formulation and within it after formulation. Id. at 134 4. Thus, without disclosing how to measure particle size post -formulation, the inventors had not demonstrated that they had in fact invented a formulated drug with sufficiently small particles. By contrast, here, the evidence established only a hypotheti cal possibility that tableting could affect particle size in a relevant way. 5 We simply cannot say that the district court committed clear error by finding that such evidence was not clear and convincing proof of invalidity. 6

5 Additionally, in Eli Lilly we were affirming the district court’s finding of invalidity, whereas here a ruling in Zydus’s favor would require us to conclude that the district court had committed clear error , a much higher standard

. 6 Takeda also points out that the district court f

ound that a skilled artisan would have known how to extract granules from a finished tablet to measure their size. However, that fact is only relevant to the enabl ement inquiry, which Zydus ha s not challenged on this basis.TAKEDA PHARMACEUTICAL CO

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C. Enablement

Under the enable ment requirement of 35 U.S.C. § 112, “the specification must enable one of ordinary skill in the art to practice the claimed i nvention without undue experimentation.” Transocean Offshore Deepwater Dril ling, Inc. v. Maersk Drilling USA, Inc.

, 699 F.3 d 1340, 1355 (Fed. Cir. 2012) (quoting Nat’l Recovery Techs., Inc. v. Magnetic Separation Sys., Inc. , 166 F.3d 1190, 1196 (Fed. Cir. 1999)). Enablement is a question of law that we review de novo based on underlying factual findings

. CFMT, Inc. v. Yieldup Int’l Corp. , 349 F.3d 1333, 1337 (Fed. Cir. 2003).
Zydus argues that the patent is invalid for lack of e nablement because a skilled artisan would not be able to determine the average particle diameter using the coulter counter method of measurement witho ut undue exper imentation. The district court concluded that Zydus had not met its burden of establishing lack of enablement by clear and convincing evidence because it had submitted only “conclusory statements” regarding the amount of experimentation nece ssary, and because there was no dispute that a skilled artisan would know how to measure particle size using laser diffraction and/or optical micro scopy. See Opinion at 29

- 30.
We agree with the district court. It is well established that the “enablemen t requirement is met if the descri ption enables any mode of making and using the inve ntion.” Johns Hopkins Univ. v. CellPro, Inc. , 152 F.3d 1342, 1361 (Fed. Cir. 1998) (emphasis added) (internal quotation marks omitted). Thus, because the patent identifi es laser diffraction as a viable measurement technique, and there is no dispute that a skilled artisan would know how to use laser diffraction to measure particle diameter, Zydus has not established that the patent is invalid for lack of enablement on this basis.TAKEDA PHARMACEUTICAL CO

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Howev er, we note for the record that if the district court had been correct that the patent requires deagglo meration prior to particle size measurement, we would be forced to reach a different conclusion regarding enabl ement. Specifically, nothing in the written description directs a skilled artisan to evaluate whether a sample contains “more than nominal” hard agglomerates prior to measurement, such that optical microscopy should be used, nor does it explain how one would make that dete rmination. Similarly, it does not explain how to conduct virtual dissection of deagglomerates using optical micro scopy. Thus, if the patent required deagglomeration prior to measurement in certain circumstances, as the district court found that it did, it could not be said that the wri tten description informed a skilled artisan how to make and use the claimed invention. However, for the reasons that follow, we believe that the district court clearly erred in making that finding and will not inv alidate the patent on that basis.
Takeda argues that the skilled artisan would simply have known to use optical microscopy (and deagglomer ation) when a sample contains more than “nominal” hard agglomerates. But the virtual dissection of agglomerates

run s counter to the lone methodology disclosed in the specification. T he only method of measurement discussed in the specification is laser diffraction, which cannot account for hard agglomerates. Indeed, there is no indic ation in the specification that the inventors themselves undertook deagglomeration of their own samples prior to
measurement , or even evaluated whether deagglomer ation was necessary

. We cannot conclude that the patent affirmatively requires a step that was entirely absent from (and even precluded by) the procedure described in the specification.
And indeed, this conclusion is entirely consistent with the underlying objective of the patent; it is the actual size of the granule itself

— regardless of how many cores it isTAKEDA PHARMACEUTICAL CO

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comprised of

— that det ermines whether or not the gra nules have a rough feeling in the mouth. If large hard agglomerates a re “virtually” dissected (a telling phrase) for measurement purposes, a sample could be measured as having an average particle diameter of 400 μm or less de spite the fact that the actual size of the granules would create significant roughness in the mouth.
In light of our conclusion that the ’994 patent does not require deagglomeration prior to particle size measur ement, we conclude that it is not invalid for lack of en ablement based on a failure to explain when and how to do

so.
C ONCLUSION For the foregoing reasons, we reverse the district court’s claim construction ruling and resulting finding of literal infringement, affirm the court’s judgment of no invalidity, and remand for further proceedings consistent with this opinion.

REVERSED

- IN

- PART , AFFIRMED

- IN

- PART , AND REMAN D ED