Full opinion text
OPINION SUE L. ROBINSON, Chief Judge. I. INTRODUCTION On October 9, 2001, Kao Corporation and The Andrew Jergens Company (collectively “plaintiffs”) filed a patent infringement action under 35 U.S.C. § 271 against Chesebrough-Pond’s USA Co. (D.I. 1) Plaintiffs allege that Chesebrough-Pond’s USA Co. infringed U.S. Patent No. 6,299,-605 (the “ ’605 patent”) by manufacturing and selling its Pond’s clear pore strips in the United States. (Id at ¶ 6) On May 12, 2001, plaintiffs filed a first amended complaint to remove Chesebrough-Pond’s USA Co. as a defendant and to add Unilever United States, Inc. and Conopeo Inc. as defendants (collectively “defendants”). (D.I. 3) On November 15, 2001, plaintiffs filed a second amended complaint alleging inducement of infringement of U.S. Patent No. 6,306,382 (the “ ’382 patent”). (D.I. 25 at ¶ 7) On December 14, 2001, defendants answered plaintiffs’ three complaints denying all infringement allegations. (D.I. 12) Defendants raised affirmative defenses of noninfringement and invalidity of the ’605 and ’382 patents for failure to comply with the patent laws of the United States and unenforceability of the ’382 patent due to inequitable conduct. (Id at ¶¶ 10, 11, 12) Defendants likewise filed a declaratory judgment counterclaim against plaintiffs seeking a declaration that the ’605 and ’382 patents are not infringed and invalid and that the ’382 patent is unenforceable due to inequitable conduct. (Id at ¶¶ 13-15) Defendants further counterclaimed that plaintiffs infringed U.S. Patent No. 6,106,-857 (the “ ’857 patent”) by the sale and offer for sale of Biore ULTRA nose strips in the United States. (Id. at ¶ 17) On January 25, 2002, plaintiffs denied defendants’ counterclaims and asserted affirmative defenses. (D.I. 14) Plaintiffs also filed a counterclaim seeking a declaratory judgment of noninfringement and invalidity of the ’857 patent. (Id.) On February 14, 2002, defendants responded to plaintiffs’ counterclaim- re-asserting infringement of the ’857 patent and denying that the ’857 patent is invalid. (D.I. 16) The court has jurisdiction over this suit pursuant to 28 U.S.C. §§ 1381, 1338(a). During fact discovery, the parties agreed to dismiss all claims relating to both the ’605 patent and the ’857 patent. (D.I. 66 at 1) Subsequently, plaintiffs withdrew their claim for damages related to the ’382 patent, leaving only claims for injunctive relief and attorney fees in suit. (Id. at 2) For three days in October 2003, the parties tried before the court the issues of: (1) claim construction; (2) infringement; (3) invalidity based upon inadequate written description, indefiniteness, and obviousness; and (4) unenforceability based on inequitable conduct. The following are the court’s findings of fact and conclusions of law pursuant to Fed.R.Civ.P. 52(a). II. FINDINGS OF FACT A. The Parties 1. Plaintiff Kao Corporation is a Japanese corporation with its corporate headquarters in Tokyo, Japan. (D.I. 77 at ¶ 1) 2. Plaintiff The Andrew Jergens Company is a Delaware corporation with its corporate headquarters in Cincinnati, Ohio. (Id. at ¶ 2) 3. Defendant Unilever United States, Inc. is a Delaware corporation with its corporate headquarters in New York, New York. (Id. at ¶ 3) 4. Defendant Conopeo, Inc. is á New York corporation with its headquarters in New York, New York. (Id. at ¶ 4) B. The’382 Patent 5. The application which matured into the ’382 patent was filed ón November 12, 1996 and entitled “Keratotie Plug Remover.” 6. The ’382 patent was granted on October 23, 2001. 7. The named inventors include Tom-ohiro Uemura, Masanori Tanahashi, and Yoshinao Kono. Plaintiffs jointly own the ’382 patent. (Id. at Ex. A) 8. The ’382 patent claims priority as a divisional' application to- U.S. Application No. 463,274 filed on June 5, 1995, which claims priority as a continuation-in-part of U.S. Application No. 210,778 filed on March 21, 1994, which claims priority as a continuation-in-part of U.S. Application No. 882,979 filed on May 14,1992. 9. The ’382 patent generally discloses a keratotie plug remover composition and method of removing keratotie plugs from the skin. (’382 patent, col. 1 at 11. 13-16) 10. The specification describes eight examples relating to the preparation and use of a liquid or semi-solid copolymer preparation. The examples do not mention drying the liquid or semi-solid copo-lymer onto a substrate, but instead discuss applying the copolymer directly to the face. Example 1 specifically states: “A panel washed their face and used the preparation on their faces at an application rate of 0.1 ml/cm.” (’382 patent, col. 6 at 11. 6-8) Example 2 states: “The polymers were individually prepared into an aqueous 20-30% by weight solution, and members of the panel used in the same manner as in Example 1.” (’382 patent, col. 7 at 11. 21-23) Similarly, example 3 describes liquid formulations that were applied as described in example 1. Examples 4-8 do not expressly state that the keratotic plug remover was applied as a liquid formulation. Nevertheless, these examples offer formulations in terms of percent weight, like the formulations described in examples 1-3. 11. The ’382 patent contains seven claims in ' total. Plaintiffs asserted only independent claim 1 and dependent claim 3 against defendants. 12. Claim 1 recites: A method for removing keratotic plugs from skin with a cosmetic article, which comprises: wetting the skin or said cosmetic article; applying onto the skin said cosmetic article; and peeling off said cosmetic article after drying; wherein said cosmetic article comprises: i) a substrate selected from the group consisting of woven cloth, non-woven cloth and a plastic film; and ii) on said substrate, a layer comprising a copolymer, in an amount effective to remove keratotic plugs, wherein said copolymer is a poly(alkyl vinyl ether/maleic acid) copolymer or a po-lyalkylvinyl ether/maleic anhydride) copolymer. (’382 patent col. 12 at 11. 58-66; col. 13 at 11.1-9) 13. Claim 3 recites: The method of claim 1, wherein said substrate is a non-woven cloth. (’382 patent, col. 13 at 11.12-13) 14. Claims 6 and 7 are also dependent claims, each reciting respectively: 6. The method of claim 1, wherein said layer comprises 5 to 70 wt. % based on the total weight of said layer of said copolymer. 7. The method of claim 1, wherein said layer comprises 5 to 40 wt. % based on the total weight of said layer of said copolymer. (’382 patent, col. 14 at 11. 6-11) 15. The specification of the ’382 patent does not define the term “cosmetic article” as used in claim 1. Instead, the specification states that “[t]he keratotic plug remover according to this invention may take a form of a poultice using cotton cloth, rayon cloth, tetron cloth, nylon cloth, either woven or non-woven, or using a plastic film sheet, beside pack preparations.” (’382 patent, col. 5 at 11. 19-25) The specification further states that “[t]he manner of removing keratotic plugs by the use of the keratotic plug remover of the invention is the same as the manner of using ordinary packs and poultice. Namely, when a pack preparation is used, it is first applied to the part of the skin which has keratotic plugs, particularly likely to the nose, chin, and forehead, and after dried, it is peeled off.” (’382 patent, col. 5 at 11. 26-28) 16. The specification of the ’382 patent does not define the term “amount effective” as used in claim 1. The specification only states that “[t]he preferable amount of the polymer to be incorporated into the keratotic plug remover preparation according to the invention is from 0.01 to 70% by weight, preferably 5 to 40% by weight based on the total weight of the preparation.” (’382 patent, col. 3 at 11. 27-30) The specification also discloses that the polymers are dissolved in solvent and that the amount of solvent is modified depending on the properties of the polymer compounds and is generally from 30 to 99.99% by weight, and preferably from 60 to 95% by weight, based on the total weight of the composition. (See ’382 patent, col. 3 at 11. 31-41) The examples describe polymer amounts in the 5 to 40% range by weight, primarily from 15 to 35% by weight. (See ’382 patent, col. 6-col. 12) C. The Prosecution History of the ’382 Patent 17. Plaintiffs filed the application, which granted as the ’382 patent, with eighteen claims. (See PX 41 at 45-47) On March 24, 1997, plaintiffs canceled claim 1 and added claims 19-28 by preliminary amendment. (See id. at 56-59) 18. On November 1, 1997, plaintiffs amended claim 19 and added new claims 29-31. (See id. at 86-87) Plaintiffs also submitted a declaration from Mr. Tomoshi-ro Uemura (“the 1997 Uemura declaration”) to overcome the rejection of claims 19-28 as obvious under 35 U.S.C. § 103(a) over U.S. Patent No. 4,026,552 (“the Guer-et ’552 patent”) or U.S. Patent No. 4,948,-585 in view of JP 53-27344. (Id. at 87-95) Mr. Uermura compared the effectiveness of keratotic plug removal for various salt-forming polymers as claimed in the ’382 patent and various non-ionic polymers. Mr. Uemura specifically tested the non-ionic polymer polyvinyl alcohol because the compound was the only one exemplified in the Gueret ’552 patent. (Id. at 72-85; see infra Conclusions of Law, Section C) In this regard, Mr. Uemura explained that pack preparations of the polymers were made. (Id. at 72) Test subjects washed their faces and then applied the polymer pack preparations at a rate of 0.1 ml/cm3. (Id.) Mr. Uemura stated that polyvinyl alcohol was evaluated to have less than a 5% removal ratio for keratotic plugs. (Id. at 74) In contrast, the select salt forming polymers disclosed in the ’382 patent were evaluated to have a greater than 20% removal ratio for keratotic plugs. (Id.) 19. On March 4, 1998, the examiner maintained the obviousness rejection in a final rejection, despite the comparative test data presented in the 1997 Uemura declaration. (Id. at 100) The examiner reasoned that “[t]he polyacrylic salts of Gueret et al. are not distinguishable from ‘salt-forming’ group-containing polymers as claimed. The [1997] Uemura [declaration results show improvement with use of certain copolymers which are comprised of critical monomers. Thus, the claims are not commensurate in scope with the [declaration showing.” (Id. at 101) 20. On March 27, 1998, the examiner participated in an interview with plaintiffs. (Id. at 104) The examiner noted in the interview summary that “[cjlaims are suggested to be limited to the scope of copolymers of Uemura et al 5,512,277. Keratotic plug removal effectiveness is suggested as a necessary claim limitation. Claims so limited may overcome the rejections of record.” (Id.) 21. On August 10, 1998, plaintiffs filed a notice of appeal of the final rejection. (Id. at 106) On October 8, 1998, plaintiffs engaged in another interview with the examiner regarding the appeal. (Id. at 109) The examiner recorded in the interview summary that a continued prosecution application (“CPA”) was to be filed. (Id.) 22. On October 8, 1998, plaintiffs filed a CPA cancelling claims 19-31 and adding new claims 32-38. (See id. at 116-117) Claims 32 and 38 recited respectively: 32. A cosmetic article, comprising: i) a substrate selected from the group consisting of woven cloth, non-woven cloth and a plastic film; and ii) a layer comprising 5 to 70 wt % based on the total weight of said layer of a copolymer comprising an alkyl vinyl ether and maleic acid or an anhydride on said substrate. 38. A method for removing keratotic plugs which comprises applying the ker-atotic plug remover composition of Claim 32 onto the nose, and peeling off said composition after said composition is dried. (Id. at 116-117) 23. On December 30, 1998, the examiner indicated in an interview summary that the “claims [would] be amended by examiner’s amendment to define the copolymer units and keratotic plug removal activity.” (Id. at 125) The examiner also stated that claims 32-38 were allowable with the aforementioned changes. (Id.) Thereafter, the examiner provided a formal notice of allowability for claims 32-38. (Id. at 127) 24. On March 25, 1999, after paying the issue fee, plaintiffs filed a petition to withdraw the case from issue. (Id. at 133) Plaintiffs sought to submit additional references resulting from a prior art search. 25. On May 16, 1999, plaintiffs filed a second CPA and a preliminary amendment to revise claim 38. 38. (Amended) A method for removing keratotic plugs which comprises applying [the keratotic plug remover composition of Claim 32] a cosmetic article, comprising: i) a substrate selected from the group consisting of woven cloth, non-woven cloth and a plastic film; and ii) a layer comprising a copolymer based on monomer units comprising an alkyl vinyl ether and a monomer selected from the group consisting of maleic acid or an an-hydride on said substrate, onto the [nose] skin, and peeling off said composition after said composition is dried. (Id. at 141)(underlined text shows additions and bracketed text shows deletions) Plaintiffs stated that “[a]pplicants have discovered that a cosmetic article having a substrate [ ] deposited thereon, said copo-lymer is unexpectedly superior in removing keratotic plugs, as compared with an article having deposited thereon a polymer which does not contain salt forming groups.” (Id. at 142-143) 26.On May 21, 1999, plaintiffs submitted a second declaration from Mr. Uemura (“1998 Uemura declaration”) with test results describing keratotic plug removal. (Id. at 150-152) Mr. Uemura submitted data for two samples of a copolymer solution of a particular weight PYM7MA (i.e., Gantretz AN-169, molecular weight 70,-000). Mr. Uemura discussed coating an aqueous solution of Gantretz AN-169 on a plastic liner and then covering the layer of copolymer with a sheet of non-woven rayon, thereby impregnating the copolymer solution onto the sheet. (Id.) Mr. Uemura explained: [T]he impregnated rayon non-woven sheet was dried and the final product was obtained. The content of copolymer in the pack ... was 78%.... The pack was used by wetting with water, then applied to the nose. (Id. at 151) Mr. Uemura reported that the pack was removed after fifteen minutes with a keratotic plug removal ratio of 23%. (Id.) Mr. Uermura concluded: The data described above, demonstrating the effectiveness of a copolymer of methylvinylether and maleic anhydride is commensurate in scope for claims directed to a method of keratotic plug removal using a copolymer of an alkyl vinyl ether and maleic acid or an anhy-dride thereof, as there is no reason to expect any significant difference in kera-totic plug removal for other polymers within the claimed genus. (Id.) 27. On November 3, 1999, plaintiffs participated in another interview with the examiner. (Id. at 168) The examiner stated that the application was in condition for allowance provided that the claims were amended to recite that the polymer was present in an amount sufficient to remove keratotic plugs. (Id.) 28. On November 19, 1999, plaintiffs amended claim 38 for a second time to add the language suggested by the examiner. 38. (Twice Amended) A method for removing keratotic plugs which comprises applying a cosmetic article, comprising: i) a substrate selected from the group consisting of woven cloth, non-woven cloth and a plastic film; and ii) a layer comprising a copolymer, in an amount effective to remove ker-atotic plugs, based on monomer units comprising an alkyl vinyl ether and a monomer selected from the group consisting of maleic acid or an anhydride thereof on said substrate, onto the [nose] skin, and peeling off said composition after said composition is dried[, wherein said article possesses ker-atotic plug removal activity]. (Id. at 167-168)(underlined text shows additions and bracketed text shows deletions) 29. On March 23, 2000, plaintiffs submitted preliminary remarks to the examiner in conjunction with an information disclosure statement and a petition to correct inventorship. (Id. at 191-93) Plaintiffs also supplemented the test data originally presented to the examiner in the 1998 Uemura declaration. Plaintiffs explained that Gantretz AN-119, a copolymer of PVM/MA having a molecular weight of 20,000, has been tested for the ability to remove keratotic plugs in addition to the samples of Gantretz AN-169. Plaintiffs shared that the Gantretz AN-119 had a keratotic removal ratio of 14%. Plaintiffs also stated: Although the molecular weight of 20,000 is not as close to the molecular weight of 70,000 previously reported, the copolymer at a molecular weight of 20,000 still showed an increased effectiveness at this much lower molecular weight.... The additional test results provides further support of the effectiveness of the claimed copolymer based on monomer units comprising an alkyl vinyl ether and a monomer selected from the group consisting of maleic acid or an anhydride thereof. (Id. at 192) 30. On September 29, 2000, plaintiffs submitted a third amendment to claim 38 in response to an office action issued by the examiner on June 1, 2000. 38. (Three times amended) A method for removing keratotic plugs which comprises applying a cosmetic article, comprising: i) a substrate selected from the group consisting of woven cloth, non-woven cloth and a plastic film; and ii) a layer comprising a copolymer, in an amount effective to remove keratotic plugs, based on monomer units comprising an alkyl vinyl ether and a monomer selected from the group consisting of maleic acid or an anhy-dride thereof on said substrate, onto the skin, and the peeling off said [compositing] cosmetic article after said composition is dried. (Id. at 206-207))(underlined text shows additions and bracketed text shows deletions) Plaintiffs explained that this amendment was intended to clarify the claim and correct a typographical error in the last line. (Id. at 207) Plaintiffs also submitted a declaration from Mr. Tomohiro Fukita to clarify the data presented in the 1998 Uemura declaration. (Id. at 214-215) Mr. Fukita performed additional testing with the same polymer solution used by Mr. Uemura (i.e., Gantretz AN-169). (Id.) Mr. Fukita described neutralizing the copolymer solution by adding NaOH to bring the pH of the solution to a pH of 6 prior to impregnating the sheet with polymer. (Id. at 215) Mr. Fukita explained: “The polymer solution was quickly covered with a sheet of non-woven ... and dried. In order to determine the keratotic plug removal effectiveness, the pack was wetted with water and applied to the nose of four subjects. After nose application, the pack was allowed to dry for about [fifteen] minutes.” (Id.) Mr. Fukita tested two packs and measured the polymer content to be 78.8% and 79.6%. (Id. at 216) Mr. Fukita reported that the average keratotic plug removal was 24%. (Id.) 31. On January 16, 2001, plaintiffs participated in another interview with the examiner. In the interview summary, the examiner acknowledged that Japanese reference 25871 “has carboxylic copolymer but no showing of effectiveness to remove keratotic plugs or substrate. Copolymers will be limited to maleic anhydride/methyl vinyl ether and maleic acid/methyl vinyl ether with terms such as ‘based on’ or ‘comprising monomers’ being deleted.” (Id. at 247) The examiner also documented that plaintiffs agreed to clarify the wetting and drying steps of claim 38. (Id. at 248-249) The examiner noted that the claims so limited were allowable. (Id.) 32. On February 22, 2001, plaintiffs amended claim 38 for the fourth time pursuant to their agreement with the examiner. 38. (Four times Amended) A method for removing keratotic plugs from skin with a cosmetic article, which comprises: wetting the skin or said cosmetic article; applying onto the skin [a] said cosmetic article; and peeling off said cosmetic article after drying; wherein said cosmetic article comprises; [, comprising:] i) a substrate selected from the group consisting of woven cloth, non-woven -cloth and a plastic film; and ii) on said substrate, a layer comprising a copolymer, in an amount effective to remove keratotic plugs, wherein said copolymer is a poly(alkyl vinyl ether/maleic acid) copolymer or a poly(alkyl vinyl ether/maleic anhydride) copolymer [based on monomer units comprising an alkyl vinyl ether and a monomer selected from a group consisting of maleic acid or an an-hydride thereof on said substrate, onto the skin, and peeling off said cosmetic article after said composition is dried]. (Id. at 266)(underlined text shows additions and bracketed text shows deletions) Plaintiffs explained that “[t]he claim has further been amended to clarify the steps of the method. The addition of the wetting step is not further limiting since the wetting step was implied in the previously submitted claim. No new matter would be added by entry of this amendment.” (Id. at 260) D. History of the 1998 Uemura Declaration 33. In 1998, under the supervision of Mr. Uemura, Mr. Fukita tested the kera-totic plug removal capacity of Gantretz AN-119, Gantretz AN-169, and polyvinyl alcohol. (DTX 192) He reported the results of this testing in his laboratory notebook. The low molecular weight Gantretz AN-119 sample had a keratotic removal ratio of 14.2% with an error of 5.2%, whereas the higher molecular weight Gan-tretz AN-169 sample had a keratotic removal ration of 23.3% with an error of 7.1%. (Id.) Mr. Fukita also documented that the polyvinyl alcohol sample had a keratotic removal ratio of 3.7%; he did not record a margin of error for this sample. (Id.) 34. Mr. Fukita could not remember why he opted to test two different molecular weights of PVWMA. (D.I. 88 at 715) 35.The persons involved in the 1998 Uemura declaration are not able to explain how the data was selected for presentation to the examiner. In this regard, Mr. Uemura could not remember why he did not report the results for the low weight Gantretz AN-119 or the margins of error in his declaration. (Id. at 694-695, 697; 719) Mr. Uemura testified in his deposition as follows: Q: Did you decide not to include the margin of errors in the results that you reported in your declaration? A: I don’t remember. Q: Do you know if anyone knows why the margin of error was not included in the results that you reported in your declaration marked as Exhibit 22? A: That’s the document I declared, and I don’t know. * * * * * Q: So you’re the only person who can explain why the margin of error was not included in your declaration; is that what you are saying? A: I declared the document, and I could be the only one who knows why. Q: But as you sit here today, you’re not able to explain to me why a margin of error was not included in the declaration; is that correct? A: No. I have not said such a thing. Q: Then please explain to me why a margin of error was not included in your declaration. A: I said I don’t remember. (Id. at 694-95) Similarly, Mr. Fukita stated in his deposition: Q: And did you provide these results to Mr. Uemura? A: I don’t remember. Q: Do you know if these results were ever incorporated into a declaration? A: I don’t remember. May I take a break? (Id.) Mr. Richard Chinn, the patent attorney who helped to prepare the 1998 Uemu-ra declaration, likewise testified in his deposition: Q: Do you know whether the results that appear in this declaration reflect all the results that were obtained in experiments performed to obtain these results? Hi H< H* Hi ■ Hs Hi A: I cannot recall. Q: Do know if additional results were transmitted to you, but you — but chosen not to be submitted to the PTO at the time that that declaration was being prepared? A: I can’t recall. Q: Is it possible that additional results were transmitted to and chosen by you not to submit to the PTO? A: I don’t recall. Q: You don’t recall if that’s possible? A: I can’t recall the time frame, so I can’t recall. (Id. at 766-67) 36.Mr. Chinn was unable to explain any of the circumstances surrounding the late disclosure of the keratotic removal ratio for the Gantretz An-119 sample. He stated the following during his deposition: Q: Whose decision was it to submit the results that are reported here in the last two paragraphs of Page 2 of Exhibit 23 [referring to the preliminary remarks dated March 23, 2000]? * * * * Hi Hi A: I cannot recall. Q: Where did you get the data that you reported in the preliminary remarks on Page 2 of the preliminary remarks? A: I cannot recall. (Id. at 782) E. Plaintiffs’ Other Patent Filings 37. Five years after filing the application which granted as the ’382 patent, plaintiffs filed U.S. Application No. 843,857 on April 30, 2001. This application granted on August 19, 2003 as U.S. Patent No. 6,607,719 (the “’719 patent”) and claimed priority as a continuation of the ’382 patent. It has the same specification as the ’382 patent and contains four claims. Claim 1 is directed to a method for removing keratotic plugs from skin with a cosmetic article. This claimed method recites the exact steps and substrate disclosed in claim 1 of the ’382 patent. Claim 1 of the ’719 patent, however, changes the co-polymer composition. In particular, claim 1 of the ’719 patent recites: “wherein said copolymer is a copolymer containing units obtained from (a) a member selected from the group consisting of alkyl vinyl ethers and derivatives thereof and (b) at least one member selected from the group consisting of maleic acid, maleic anhydride, and derivatives thereof, or a salt of said copo-lymer.” (’719 patent, col. 10 at 11. 48-53) Claim 4 of the ’719 patent is dependent on claim 1 and recites: The method of claim 1, wherein said effective keratotic plug removal amount is in a range of from 0.01 to 70% by weight of total polymer composition. (’719 patent, col. 10 at 11. 59-61) F. The Accused Infringing Product 38. Defendants’ Pond’s clear pore strips are advertised to remove blackheads and unclog pores. (See PTX 66; see also DTX 44) 39. The Pond’s clear pore strips consist of a coated non-woven fabric. (PX 73 at CP014324) 40. The product lists the ingredients used in the manufacture of defendants’ product as PVM/MA copolymer and ami-nomethyl propanol (“AMP”). (PTX 66; DTX 44) 41. The coating for the Pond’s clear pore strips is specifically prepared by mixing 98% by weight of a solution of PVM/MA with 2% by weight of AMP. (PX 73 at CP014328; D.I. 208, 211) The AMP reacts with the PVM/MA to form a salt, as shown in the figures below, designated as the “AMP-Reacted PVM/MA Salt” and “Acid-Salt Copolymer,” respectively. (D.I. 86 at 215-216; D.I. 87 at 417-418, 422; DTX 508; DTX 509) Nevertheless, the neutralization reaction does not go to 100% completion; only 15% of the acid groups include a salt. (See D.I. 86 at 102-103) Put differently, 29% of the repeating PVM/MA monomer units include a salt while 71% of the repeating PVM/MA momomer units do not include a salt. (See id. at 223) 42. The PVM/MA acid-salt has physical and chemical properties distinct from the PVM/MA starting material. Specifically, the PVM/MA acid-salt has a different solubility, viscosity, chemical spectra, acidity, and plasticity than the claimed PVM/MA. First, the claimed PVM/MA and AMP are separately soluble in the solvent tetrahydrofuran (“THF”) whereas the PVM/MA acid-salt forms an insoluble gel in THF. (See id. at 207-210; 242-243; see also DTX 507) This solubility difference indicates that the chemical bonding in the PVM/MA acid-salt is different from the chemical bonding in the claimed PMV/MA. (See D.I. 86 at 212) Second, the viscosity of the PVM/MA acid-salt is 100% greater than the viscosity of the claimed PVM/MA. The viscosity of the PVM/MA acid-salt is also greater than the viscosity of the AMP. (See id. at 229-234; see also DTX 511) Third, the PVM/MA acid-salt displays a spectral peak at approximately 1702 centimeters'1 that is smaller than the spectral peak for the claimed PVM/MA at this same retention. CSee D.I. 86 at 236-242; see also DTX 512) This spectral peak corresponds to the car-boxylic acid group. The PVM/MA acid-salt also shows the presence of a spectral peak at 1520 centimeters _1 corresponding to a salt group. (Id.) The formation of the salt peak indicates that the some of the acid groups present in PVM/MA are consumed when PVM/MA is reacted with AMP to form the acid-salt. (Id.) Finally, the PVM/MA acid-salt is also less brittle and less acidic than the claimed PVM/MA. (See, e.g., D.I. 87 at 314) 43. The instructions provided on the Pond’s clear pore strips product state: After washing your face, simply remove a [cjlear [p]ore [s]trip from foil pack and: 1. Wet your finger with water and use it to moisten the smooth side of the strip. 2. Apply wetted strip to face. Smooth out air bubbles, ensuring good contact with skin. Let dry about 15 minutes-the strip should feel dry and stiff. 3. For best results, slowly and carefully peel off strip. Instantly see the results! 4. You’ll feel clearer, smoother skin with smaller pores as blackheads, dirt and oil are removed from clogged pores. (PTX66; DTX 44) III. CONCLUSIONS OF LAW A. Claim Construction 1. The parties dispute the meaning of three terms present in claim 1:(1) cosmetic article; (2)copolymer; and (3) amount effective. First, plaintiffs argue that the term “cosmetic article” refers to a dried pore strip product. In contrast, defendants assert that the term refers to a liquid or semi-solid pack preparation or a poultice upon which a liquid copolymer preparation has been layered, but not dried. Second, plaintiffs contend that the term “copolymer” includes the two copo-lymers recited in claim 1, as well as the salt forms of these copolymers. Defendants, in rebuttal, claim that the term “copolymer” covers only the two specifically enumerated copolymers, namely, (1) poly(alkyl vinyl ether/maleic acid); and (2) poly(alkyl vinyl ether/maleic anhydride), not salt forms thereof. Finally, plaintiffs aver that the term “effective amount” refers to any amount of copolymer whereas defendants argue that this term means that the amount of copolymer must be between 0.01 and 70% copolymer by weight based on the total weight of the copolymer layer. 2. Claim construction is question of law. Markman v. Westview Instruments, Inc., 52 F.3d 967, 979 (Fed.Cir.1995) (en banc). 3. In interpreting the claims, a court should begin with the intrinsic evidence of record (i.e., the patent itself, including the claims, the specification, and the prosecution history). Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed.Cir.1996). “Such intrinsic evidence is the most significant source of the legally operative meaning of disputed claim language.” Id. 4. First, a court should look to words of the claims themselves to define the scope of the patented invention. Id. There is a heavy presumption that the claim terms carry their ordinary and customary meanings as would be understood by one of ordinary skill in the art. Mark-man, 52 F.3d at 986. In other words, the court must determine how a person of experience in the field of the invention would, upon reading the patent documents, understand the words used to define the invention. Toro Co. v. White Consol. Indus., Inc., 199 F.3d 1295, 1299 (Fed.Cir.1999). Dictionaries and scientific treatises may help to supply the pertinent context and usage for claim construction. Tex. Digital Sys., Inc. v. Telegenix, Inc., 308 F.3d 1193, 1201, 1202 (Fed.Cir.2002). 5. Second, because a patentee may choose to be his own lexicographer and use a term in a manner either more or less expansive than its general usage in the relevant art, the court also should review the specification to determine whether an inventor has used any term in a manner other than its ordinary meaning. Vitronics, 90 F.3d at 1582. The specification may act as a dictionary when it either expressly defines terms used in the claims or when it defines terms by implication. Id. 6. Third, a court may consider the prosecution history of a patent, if in evidence. Id. “The prosecution history limits the interpretation of claim terms so as to exclude any interpretation that was disclaimed during prosecution.” Id. (quoting Southwall Tech., Inc. v. Cardinal IG Co., 54 F.3d 1570, 1576 (Fed.Cir.1995)). That is, a court must look to the prosecution history to determine if the patentee has limited the scope of the claims by disclaiming a particular interpretation during prosecution. Biodex Corp. v. Loredan Biomedical, Inc., 946 F.2d 850, 862 (Fed.Cir.1991). 7. Additionally, if the meaning of a term is not clear from the intrinsic evidence, then a court may consult extrinsic evidence, such as expert testimony, in construing claim terms as they would be understood in the relevant art. Markman, 52 F.3d at 980-81. 8. When construing the claims, courts must take great care to avoid importing unnecessary limitations into the claims from the specification. Amgen Inc. v. Hoechst Marion Roussel, Inc., 314 F.3d 1313, 1325 (Fed.Cir.2003). “If we once begin to include elements not mentioned in the claim in order to limit such claim ... we should never know where to stop.” Johnson Worldwide Assocs., Inc. v. Zebco Corp., 175 F.3d 985, 990 (Fed.Cir.1999)(quoting McCarty v. Lehigh Val. R.R., 160 U.S. 110, 116, 16 S.Ct. 240, 40 L.Ed. 358 (1895)). Nevertheless, a court should look to the specification to determine whether it refers to a limitation only as a part of less than all possible embodiments or whether it suggests that the very character of the invention requires the limitation be a part of every embodiment. It is impermissible to read the one and only disclosed embodiment into a claim without other indicia that the patentee so intended to limit the invention. Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1327 (Fed.Cir.2002). On the other hand, where the specification makes clear at various points that the claimed invention is narrower than the claim language might imply, it is entirely permissible and proper to limit the claims. SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1345 (Fed.Cir.2001). 9. The court construes the term “cosmetic article” to mean a liquid, semisolid, or dried preparation used to beautify the body by application. At the outset, the court observes that the adjective “cosmetic” means “a preparation, such as skin cream, designed to beautify the body by direct application.” American Heritage Dictionary 328 (New College Ed.1976). Thus, the use of this term imparts the idea that an “article” is applied to the skin for purposes of beautification. While defendants contend that the “article” is limited to liquid and semi-solid preparations based upon the use of the terms “pack” and “poultice” in the specification, the court notes that the specification, through the use of the term “may,” offers these two formulations as examples only. “The ker-atotic plug remover according to this invention may take a form of a poultice ... beside pack preparations.” (’382 patent, col. 5 at 11. 19-22) (emphasis added) This permissive “may” language does not restrict the claimed invention to a particular formulation, but instead expressly leaves open the possibility of other formulations. Further, the court declines to limit the claimed invention to a liquid formulation based upon the examples alone, despite the fact that each example discloses either expressly or implicitly a liquid formulation. Indeed, the Federal Circuit has cautioned against restricting the claims based upon the embodiments described in the specification, stating “[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.’” Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 906 (Fed.Cir.2004)(quoting Teleflex, 299 F.3d at 1327). The court, therefore, concludes that it would be improper to limit plaintiffs to a liquid formulation, particularly since the prosecution history reveals that plaintiffs submitted data for dry formulations; i.e., in amending claim 1 to include the wetting language, plaintiffs argued that the “the addition of the wetting step is not further limiting since the wetting step was implied in the previously submitted claim.” (PX 41 at 260) 10. The court construes the term “copolymer” to mean either poly(alkyl vinyl ether/maleic acid) copolymer or poly(alkylvinyl ether/maleic acid anhy-dride) copolymer, but not the salt form thereof. While the written description sets forth a variety of copolymers, including ones with mixtures of anionic monomers, cationic monomers, and amphoteric monomers, plaintiffs opted to narrowly define the term copolymer in claim 1 as being either the acid or anhydride form of poly(alkyl vinyl ether/maleic acid) by stating “said copolymer is a poIy(alkyI vinyl ether/maleic acid) copolymer or a polyal-kylvinyl ether/maleic anhydride) copolymer.” (’382 patent, col. 13 at 11. 6-8) The court declines to broaden the plain language of the claim by reading a salt limitation into it, especially since a salt copolymer is a distinct chemical entity from both an acid copolymer and an anhydride copo-lymer. 11. The prosecution history of the ’382 patent supports the court’s construction of the term “copolymer.” Claim 1 of the ’382 patent originally was written to cover only maleic acid and maleic anhydride, not the salt form. To this end, claim 1 originally recited “a copolymer comprising an alkyl vinyl ether and maleic acid' or an anhy-dride on said substrate.” Claim 1 later was amended to recite “monomer units comprising an alkyl vinyl ether and a monomer selected from the group consisting of maleic acid or an anhydride thereof.” (PX 41 at 116-177; 141) This claim did not contain any express or inherent recitation of a salt form. Plaintiffs ultimately amended this language to eliminate the terms “monomer units” pursuant to an interview with the examiner wherein he specifically limited the ■ claims to maleic acid/methyl vinyl ether and maleic anhy-dride/methyl vinyl ether. (See id. at 248-249) Subsequently, plaintiffs filed the ’719 patent with claims specifically directed to salts of the copolymers claimed in the ’382 patent. If applicants had intended the claims of the ’382 patent to include these salt forms, then there would have been no need to file the ’719 patent as a continuation of the ’382 patent. Otherwise, the ’719 patent would contain claims to an invention previously claimed in the ’382 patent. 12. The court construes the term “amount effective” in the context of an invention pertaining to beautification of the skin to mean “an amount sufficient to have a cosmetic benefit by removing kera-totic plugs.” This construction aligns with both the plain meaning and customary usage of the term. Contrary to defendants’ assertion that the amount of copolymer present must be between 0.01 and 70% by weight based on the total weight of the copolymer layer, the language in claim 1 does not expressly require a minimum or maximum amount of copolymer to be effective. The concept of claim differentiation provides added support for the instant claim construction. Dependent claims 6 and 7 recite the preferred embodiments, namely, copolymer of 5 to 70 wt. % and 5 to 40 wt. % based on total .weight. (See ’382 patent, col. 14 at 11. 6-11) Although defendants argue in favor of a slightly lower limit on the polymer weight rapge, i.e., 0.01% as opposed to the 5% recited in claims 6 and 7, the court, nonetheless, infers that the juxtaposition of independent claim 1 lacking any reference to a weight percentage of copolymer with two dependent claims containing weight percentages of copolymer implies that plaintiffs did not intend to require a weight percentage of copolymer in claim 1. Indeed, “the presence of a dependent claim that adds a particular limitation raises a presumption that the limitation in question is not found in the independent claim.” Liebel-Flarsheim, 358 F.3d at 910 (citing Wenger Mfg., Inc. v. Coating Mach. Sys., Inc., 239 F.3d 1225, 1233 (Fed.Cir.2001)). Additionally, the specification does not mandate a limited interpretation of the disputed claim language, even though the written description discloses copolymer weight ranges in preferred embodiments and all of the examples recite copolymers of less than 70% by weight. As mandated by the Federal Circuit, the court shall read the claims in light of the specification, but will not read limitations found in the specification into the claims absent a clear manifestation that the applicants intended for their claimed invention to be limited in such fashion. Furthermore, the prosecution history substantiates the court’s construction of the term “amount effective.” In submitting the second CPA in May 1999, plaintiffs cancelled the pending claims 32-37 and amended claim 38 to remove its dependency on claim 32, presenting it as the broadest independent claim. In doing so, plaintiffs eliminated the limitation requiring the polymer layer to comprise 5 to 70 % based on total weight and added dependent claims reciting both the 5 to 70 wt. % and the 5 to 40 wt. % limitations. The court concludes that this amendment evidences plaintiffs’ belief that their invention, in its absolute broadest form, was not contingent upon a particular weight range of copolymer. B. Literal Infringement of the ’382 Patent 13. Plaintiffs assert that the Pond’s clear pore strips product meets all of the limitations found in claims 1 and 3 of the ’382 patent. Defendants contend in response that their product does not meet the “cosmetic article,” “copolymer,” and “amount effective” limitations of claims 1 and 3. In this regard, defendants argue that Pond’s clear pore strips are not a cosmetic article because they are sold in dry form. Defendants also assert that the coating of its pore strips is not either form of PVM7MA disclosed in claim 1. Instead, defendants contend that AMP reacts with PVM/MA forming a salt. Additionally, defendants charge that their product contains more than 70% by weight copolymer and, therefore, would not meet the “amount effective” limitation if it is construed to mean a copolymer of from 0.01 to 70% by weight. 14. A patent is infringed when a person “without authority makes, uses or sells any patented invention, within the United States ... during the term of the patent.” 35 U.S.C. § 271(a). 15. A court should employ a two-step analysis in making an infringement determination. Markman, 52 F.3d at 976. First, the court must construe the asserted claims to ascertain their meaning and scope. Id. Claim construction is a question of law subject to de novo review. See Cybor Corp. v. FAS Techs., 138 F.3d 1448, 1454 (Fed.Cir.1998). Second, the trier of fact must compare the properly construed claims with the accused infringing product. Markman, 52 F.3d at 976. This step is a question of fact. See Bai v. L & L Wings, Inc., 160 F.3d 1350, 1353 (Fed.Cir.1998). Literal infringement occurs where each limitation of at least one claim of the patent is found exactly in the alleged infringer’s product. Panduit Corp. v. Dennison Mfg. Co., 836 F.2d 1329, 1330 n. 1 (Fed.Cir.1987). 16. The patent owner has the burden of proving infringement and must meet its burden by a preponderance of the evidence. SmithKline Diagnostics, Inc. v. Helena Lab. Corp., 859 F.2d 878, 889 (Fed.Cir.1988) (citations omitted). 17. The court finds that defendants’ accused product meets the “cosmetic article” limitation of the asserted claims of the ’382 patent. The court construed the term “cosmetic article” to include liquid, semi-solid, and dry preparations applied to beautify the body. Since defendants’ product is a dry, solid pore strip applied to the body for purposes of beautification, it meets the cosmetic article limitation. 18. The court finds that defendants’ accused product also meets the “amount effective” limitation of the asserted claims of the ’382 patent. As construed by the court, the term “amount effective” means “an amount sufficient to have a cosmetic benefit by removing keratotic plugs” and is not restricted to a 0.01 to 70% .copolymer by weight range as advocated by defendants. The undisputed evidence shows that defendants’ product contains 93% by weight copolymer, an amount sufficient to remove keratotic plugs. 19. The court has construed the “copolymer” limitation to mean either poly(alkyl vinyl ether/maleic acid) copolymer or poly(alkylvinyl ether/maleic anhy-dride) copolymer, but not the salt form thereof. The experts agree that the defendants’ product contains PVM/MA copo-lymer and AMP and that the AMP reacts with the maleic acid to neutralize a number of the PVM/MA monomer units, thereby forming PVM/MA acid-salt. The experts also agree that the claimed PVM/MA copolymer and the PVM/MA acid-salt have different chemical compositions which can be characterized by differences in their solubility, viscosity, and infrared spectra data. 20. Despite the uncontested differences in chemical composition between the claimed PVA/MA and the PVA/MA acid-salt, plaintiffs assert that the PVA/MA acid-salt literally infringes the copolymer limitation of claim 1 of the ’382 patent. In support of their assertion, plaintiffs direct the court to the Federal Circuit’s decision in Merck & Co., Inc. v. Teva Pharms. USA, Inc., 347 F.3d 1367 (Fed.Cir.2003). In that case, the claim at issue addressed the administration of an effective amount of “4-amino-l-hydroxybutane-l, 1-biphos-phonic acid” for the treatment of urolithia-sis and to inhibit bone reabsorption. In concluding that the salt form of the claimed acid literally infringed, the Federal Circuit relied on: (a) a specification that contained numerous references to the salt form of the claimed acid; (b) consistent testimony from “all the qualified witnesses” that “persons in this field would understand that the acid is the active agent and that the acid is administered when it is in the form of the salt;” and (c) “extensive evidence that persons experienced in this field use the same lexicography as did the inventors in referring to the active ingredient ‘in the form of the salt.” Id. at 1371. As described by the Federal Circuit, [t]he question is not whether a general chemist would know the difference between an acid and a salt. The question is whether a person experienced in the field of the invention and familiar with the usages of pharmacology and the pri- or art, reading the patent specification, would know that for-the treatment of urolithiasis and to inhibit bone reabsorption, the statement that 4-amino-l-hy-droxybutane-l, 1-biphosphonie acid is administered to treat these diseases, encompasses administration as the acid salt. All of the pharmacologist witnesses agreed that this was the correct reading. • Id. at 1371-72. 21. Clearly, the record at bar does not include such compelling evidence. Neither is the evidence of record consistent with the reasoning of the Federal Circuit in Stiftung v. Renishaw PLC, 945 F.2d 1173 (Fed.Cir.1991). In that case, the Federal Circuit held that one cannot avoid infringement merely by adding elements if each element recited in the claims is found in the accused device. For example, a pencil structurally infringing a patent claim would not become noninfringing when incorporated into a complex machine that limits or controls what the pencil can write. Id. at 1178 (quoting A.B. Dick Co. v. Burroughs Corp., 713 F.2d 700, 703 (Fed.Cir.1983)). The question at bar is whether, by adding AMP to the claimed PVA/MA copo-lymer, the resulting product (PVA/MA acid-salt) is still literally within the scope of claim 1 of the ’382 patent. Although plaintiffs’ expert testified generally that the claimed PVA/MA copolymer and the PVA/MA acid-salt “fall[ ] under the family of the copolymer” (see, e.g., D.I. 86 at 108), this evidence, when compared to the record as a whole, fails to make the scales tip even somewhat on plaintiffs’ side. To put the point differently, plaintiffs have failed to carry their burden of proving by a preponderance of the evidence that the accused product literally meets the copo-lymer limitation of claim 1 of the ’382 patent. C. Invalidity 22. Defendants assert that the ’382 patent is invalid for: (1) lack of an adequate written description of the claim language “wetting the skin or said cosmetic article” and “amount effective;” (2) indefiniteness in use of the term “amount effective;” and (3) obviousness. “A patent shall be presumed valid.” 35 U.S.C. § 282. To overcome this presumption, the party challenging a patent must prove facts supporting a determination of invalidity by clear and convincing evidence. Apotex USA, Inc. v. Merck & Co., 254 F.3d 1031, 1036 (Fed.Cir.2001) (citing Am. Hoist & Derrick Co. v. Sowa & Sons, Inc., 725 F.2d 1350, 1360 (Fed.Cir.1984)). Based upon this teaching, defendants bear the burden of proving their invalidity claims by clear and convincing evidence. a. Written Description Under 35 U.S.C. § 112, Paragraph 1 i. The Legal Standard 23. The written description requirement of 35 U.S.C. § 112, paragraph 1, is set forth as follows: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. The written description requirement-is distinct from the enablement and best mode requirements also provided for in § 112, paragraph 1. See Univ. of Rochester v. G.D. Searle & Co., 358 F.3d 916, 921 (Fed.Cir.2004). 24. “The ‘written description’ requirement serves a teaching function, as a ‘quid pro quo’ in which the public is given ‘meaningful disclosure in exchange for being excluded from practicing the invention for a limited period of time.’ ” Id. at 922 (citing Enzo Biochem, Inc. v. Gen-Probe Inc., 323 F.3d 956, 970 (Fed.Cir.2002)). 25. Compliance with the written description requirement is a fact-based inquiry that will “necessarily vary depending on the nature of the invention claimed.” Id. at 963 (citing In re Di Leone, 58 C.C.P.A. 925, 436 F.2d 1404, 1405 (C.C.P.A.1971)). 26. The Federal Circuit has employed a fairly uniform standard for determining whether the written description requirement is satisfied. “Although [the applicant] does not have to describe exactly the subject matter claimed, ... the description must clearly allow persons of ordinary skill in the art to recognize that [he or she] invented what is claimed.” Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1563 (Fed.Cir.1991) (citations omitted). In other words, “the applicant must convey to those skilled in the art that, as of the filing date sought, he or she was in possession of the invention.” Id. To show possession,3 an applicant must describe the invention, with all its claimed limitations, and not only what makes it obvious. Lockwood v. Am. Airlines, 107 F.3d 1565, 1572 (Fed.Cir.1997). The Federal Circuit has observed that an applicant may proffer such description by way of words, structures, figures, diagrams, and formulas. Id. ii. “Wetting the Skin or Said Cosmetic Article” 27. Applying these standards to the arguments advanced by defendants, the court finds that plaintiffs complied with the written description requirement in using the language “wetting the skin or said cosmetic article” in the asserted claims. These words plainly and directly satisfy the standard employed by the Federal' Circuit in assessing written description. That is, the phrase “wetting the skin or said cosmetic article” fairly appraises persons of ordinary skill in the cosmetic field that either the cosmetic article or the skin where the cosmetic article is to be applied must be wet prior to application of the article. 28. Defendants focus their written description challenge on the language in the specification wherein plaintiffs stated that “[t]he manner of removing keratotic plugs by the use of the keratotic plug remover of the invention is the same as the manner of using ordinary packs and poultice.” (’382 patent, cok 5 at 11. 26-28) Defendants argue that packs and poultices are liquid or semi-solid objects that do not need to be wetted prior to use. By comparing the claimed invention to such objects, defendants assert that plaintiffs failed to describe their invention. Defendants, however, ignore the further description in the specification elaborating what is meant by the language “the manner of using ordinary packs and poultice.” In this regard, plaintiffs stated: “Namely, when a pack preparation is used, it is first applied to the part of the skin which has keratotic plugs, particularly likely to the nose, chin and forehead, and after dried, it is peeled off.” (’382 patent, col. 5 at 11. 28-31) Thus, the court concludes that plaintiffs intended to communicate that the claimed invention must be applied to the skin in the area plagued by keratotic plugs and then removed to draw out the keratotic plugs. The wetting step, which appears necessary to aid in the adhesion of the claimed cosmetic article, is so straightforward that a detailed description in the specification is not necessary. Therefore, the court concludes that the ’382 patent complies with the written description requirement of § 112, paragraph 1, for the phrase “wetting the skin or said cosmetic article.” iii. “Effective Amount” 29. The court finds that defendants’ argument concerning that the phrase “amount effective” rehashes their claim construction position. Nevertheless, giving defendants the benefit of the doubt, the court observes that the phrase “amount effective” readily communicates to persons of ordinary skill in the cosmetic field that the claimed invention must employ an amount of polymer sufficient to remove keratotic plugs from the skin, thereby improving the appearance of the skin in the treated region. As such, the court finds that this phrase meets the written description requirement, even though neither the precise words “amount effective” nor a particular definition for these words appear in the specification. The specification provides two preferred embodiments for the amount of polymer to be used in the keratotic plug remover preparation. The examples likewise describe polymer in specific ranges by weight. Taken together, these teachings help to show that plaintiffs were “in possession” of the claimed invention. Accordingly, the court concludes that the ’382 patent is not invalid for lack of written description based upon the use of the phrase “amount effective.” b. Indefiniteness under 35 U.S.C. § 112, Paragraph 2 30. The definiteness requirement of 35 U.S.C. § 112, paragraph 2, is set forth as follows: “A patent specification shall conclude with one or more claims that particularly [point] out and distinctly [claim] subject matter which the applicant regards as his invention.” 31. The Federal Circuit has explained that a claim satisfies § 112, paragraph 2, if one skilled in the art would understand the bounds of the claim when read in light of the specification. See Miles Lab., Inc. v. Shandon, Inc., 997 F.2d 870, 875 (Fed.Cir.1993). In determining whether this standard is met, the Federal Circuit has advised that a claim is not indefinite merely because it poses a difficult issue of claim construction. Exxon Research & Eng’g Co. v. United States, 265 F.3d 1371, 1376 (Fed.Cir.2001). Rather, the Federal Circuit has held that a claim is sufficiently clear to avoid invalidity on indefiniteness grounds “if the meaning of the claim is discernible, even though the task may be formidable and the conclusion may be one over which reasonable persons will disagree.” Id. 32. “A determination of claim indefiniteness is a legal conclusion that is drawn from the [c]ourt’s performance of its duty as the construer of patent claims.” Personalized Media Communications, LLC v. Int’l Trade Comm’n, 161 F.3d 696, 705 (Fed.Cir.1998). “By finding claims indefinite only if reasonable efforts at claim construction prove futile, [the court] accord[s] respect to the statutory presumption of patent validity, ... and [the court] protects the inventive contribution of pat-entees, even when the drafting of their patents has been less than ideal.” Id. 33. Defendants assert that the phrase “amount effective” is indefinite because persons of ordinary skill in the cosmetic field cannot determine what minimum keratotic plug removal ratio is covered by the asserted claims. The court disagrees. The court construed the phrase “amount effective” to mean “an amount sufficient to have a cosmetic benefit by removing keratotic plugs.” Under this construction, any keratotic plug removal has the cosmetic benefit of improving the appearance of the skin; there is no specific minimum keratotic plug removal ratio required by the asserted claims. In other words, the phrase “amount effective” is a functional limitation and covers all embodiments performing the recited function, to wit, all amounts of copolymer that lead to the removal of keratotic plugs. See In re Swinehart, 58 C.C.P.A. 1027, 439 F.2d 210, 213 (C.C.P.A.1971)(holding that a functional limitation covers all embodiments performing the recited function). 34.The Federal Circuit has stated that the phrase “ ‘effective amount’ is a common and generally acceptable term for pharmaceutical claims and is not ambiguous or indefinite, provided that a person of ordinary skill in the art could determine the specific amounts without undue experimentation.” Geneva Pharms., Inc. v. GlaxoSmithKline PLC, 349 F.3d 1373, 1383-1384 (Fed.Cir.2003) (citing In re Halleck, 57 C.C.P.A. 954, 422 F.2d 911, 914 (C.C.P.A.1970)). While the Federal Circuit particularly mentioned pharmaceutical type claims, the court concludes that this holding is applicable to the facts at bar, given that the asserted claims are directed at treating a skin condition much in the same way that pharmaceutical claims are directed at treating human diseases. Turning, therefore, to consider whether undue experimentation is required to determine the amount of copolymer necessary to achieve the stated function of removing keratotic plugs, the court finds simple procedures could be employed to test copolymers at a variety of % weights. Indeed, the examples describe very elementary experiments that could be easily repeated (i.e., preparing a polymer preparation using basic weighing and mixing techniques, applying the preparation to a region of skin, and then counting the number of keratotic plugs in the skin before and after administration of the preparation). Thus, the court concludes that undue experimentation is not implicated and that the ’382 patent is not invalid for indefiniteness under § 112, paragraph 2, based upon the phrase “amount effective.” c. Obviousness under 35 U.S.C. § 103 35. Defendants contend that the ’382 patent is rendered obvious by: (1) the combination of the Gueret ’552 patent and U.S. Patent No. 5,811,107 (“the Ganga-dharan ’107 patent”); (2) the combination of the Gueret ’552 patent, the Gangadhar-an ’107 patent, and the 1985 and 1986 GAF Chemical product catalogs (“the GAF catalogs”); (3) U.S. Patent No. 4,631,227 (“the Nakamura ’227 patent”) and the Ganga-dharan ’107 patent; and (4) Japanese Laid-Open Patent No. Sho 60/165902 (the JP ’902 patent) and the Gangadharan ’107 patent. i. The Legal Standard 36. In pertinent part, 35 U.S.C. § 103 provides that a patent may not be obtained ... if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the