DCT

1:19-cv-00437

Endo Pharma Inc v. Perrigo Uk FINCO Ltd Partnership

I. Executive Summary and Procedural Information

Parties & Counsel:
- Plaintiff: Endo Pharmaceuticals Inc. (Delaware)
- Defendant: Perrigo UK FINCO Limited Partnership (United Kingdom)
- Plaintiff’s Counsel: Richards, Layton & Finger, P.A.; Latham & Watkins LLP
Case Identification: 1:19-cv-00437, D. Del., 03/01/2019
Venue Allegations: Venue is alleged to be proper because the Defendant is a foreign entity that may be sued in any judicial district where it is subject to personal jurisdiction, and the complaint alleges personal jurisdiction exists in Delaware.
Core Dispute: Plaintiff alleges that Defendant's filing of an Abbreviated New Drug Application (ANDA) for a generic version of Plaintiff's Nascobal® Nasal Spray constitutes an act of infringement of six patents related to low-viscosity aqueous formulations of cyanocobalamin (Vitamin B12) and methods for their intranasal delivery.
Technical Context: The technology concerns the intranasal delivery of Vitamin B12, providing a more convenient, self-administered alternative to traditional intramuscular injections for patients with B12 deficiencies.
Key Procedural History: This case was initiated under the Hatch-Waxman Act, following Defendant's submission of an ANDA to the FDA seeking approval to market a generic drug. The ANDA included a "Paragraph IV Certification" asserting that the patents-in-suit are invalid, unenforceable, or will not be infringed. Plaintiff filed this complaint within the 45-day period provided by statute after receiving Defendant's notice letter, triggering an automatic 30-month stay of FDA approval for the generic product.

Case Timeline

Date	Event
2003-03-04	Earliest Priority Date for '636, '489, '349, '353, '714, '007 Patents
2007-06-12	'636 Patent Issued
2008-07-29	'489 Patent Issued
2011-02-01	'349 Patent Issued
2011-08-23	'353 Patent Issued
2015-01-27	'714 Patent Issued
2016-08-16	'007 Patent Issued
2019-01-24	Defendant Perrigo's Paragraph IV Notice Letter Sent
2019-03-01	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,229,636 - "Cyanocobalamin Low Viscosity Aqueous Formulations for Intranasal Delivery"

Patent Identification: U.S. Patent No. 7,229,636, issued June 12, 2007.

The Invention Explained

Problem Addressed: The patent describes that prior methods for Vitamin B12 supplementation were either inconvenient intramuscular injections or intranasal gels with an "unpleasant" consistency (U.S. Patent No. 7,229,636, col. 3:1-4). The prevailing view was that a low-viscosity aqueous solution would not remain in the nasal mucosa long enough for "useful absorption" ('636 Patent, col. 3:10-14).
The Patented Solution: The invention is a stable, mercury-free, low-viscosity (<1000 cPs) aqueous solution of cyanocobalamin that, contrary to prior art assumptions, achieves a therapeutically effective bioavailability when administered intranasally—at least 7% relative to an intramuscular injection ('636 Patent, Abstract; col. 3:46-56). The formulation typically includes a buffer, a humectant to prevent drying, and a preservative ('636 Patent, col. 5:17-35).
Technical Importance: The invention provides an effective and convenient self-administration option for Vitamin B12 therapy, which is intended to improve patient compliance by avoiding periodic injections at a physician's office (Compl. ¶31).

Key Claims at a Glance

The complaint asserts independent claim 1 and dependent claims 24, 30, and/or 31 (Compl. ¶38).
Independent Claim 1 requires:
- A stable pharmaceutical aqueous solution of cyanocobalamin comprised of cyanocobalamin and water
- A preservative selected from a specified group (e.g., benzalkonium chloride)
- A buffer selected from a specified group (e.g., citric acid, sodium citrate)
- A humectant selected from a specified group (e.g., glycerin)
- Wherein the solution is suitable for intranasal administration, has a viscosity less than about 1000 cPs
- Wherein the solution has a bioavailability of at least about 7% relative to an intramuscular injection
- With the proviso that the solution contains no mercury or mercury compounds

U.S. Patent No. 7,404,489 - "Cyanocobalamin Low Viscosity Aqueous Formulations for Intranasal Delivery"

Patent Identification: U.S. Patent No. 7,404,489, issued July 29, 2008.

The Invention Explained

Problem Addressed: Effective and consistent intranasal drug delivery requires not just a proper formulation but also a delivery device that can generate a spray with optimal physical characteristics for deposition on the nasal mucosa (U.S. Patent No. 7,404,489, col. 6:15-24).
The Patented Solution: The invention is a pharmaceutical kit that combines the aqueous cyanocobalamin solution with a specific "droplet-generating actuator." This actuator is claimed to produce a spray with a defined "spray pattern ellipticity ratio" of approximately 1.0 to 1.4 when measured at a height of 3.0 cm from the tip, ensuring a controlled and effective spray geometry ('489 Patent, Abstract; col. 7:10-26).
Technical Importance: By claiming the physical delivery system and the specific characteristics of the spray it produces, the patent aims to protect the means of ensuring the formulation is delivered effectively and consistently to the target absorption site ('489 Patent, col. 6:25-34).

Key Claims at a Glance

The complaint asserts at least independent claim 1 (Compl. ¶66).
Independent Claim 1 requires:
- A pharmaceutical kit for nasal drug delivery comprising:
- An aqueous solution of cyanocobalamin and excipients in a container; and
- A droplet-generating actuator attached to the container and fluidly connected to the solution
- Wherein the actuator produces a spray of the solution through a tip
- Wherein the spray has a spray pattern ellipticity ratio of from about 1.0 to about 1.4 when measured at a height of 3.0 cm from the actuator tip

U.S. Patent No. 7,879,349 - "Cyanocobalamin Low Viscosity Aqueous Formulations for Intranasal Delivery"

Patent Identification: U.S. Patent No. 7,879,349, issued February 1, 2011.
Technology Synopsis: This patent claims a stable aqueous solution of cyanocobalamin with similar low-viscosity and bioavailability parameters as the ’636 Patent. The claims are directed to the composition of matter itself ('349 Patent, col. 13:1-21).
Asserted Claims: 1, 9, and/or 17 (Compl. ¶88).
Accused Features: The formulation of the Perrigo ANDA Product, which is alleged to be a stable aqueous solution containing cyanocobalamin, water, a preservative, a buffer, and having a viscosity less than 1000 cPs and a bioavailability of at least 7% (Compl. ¶92).

U.S. Patent No. 8,003,353 - "Cyanocobalamin Low Viscosity Aqueous Formulations for Intranasal Delivery"

Patent Identification: U.S. Patent No. 8,003,353, issued August 23, 2011.
Technology Synopsis: This patent claims a method of administering a cyanocobalamin solution. The claimed method involves administering the solution into a nose using an actuator that produces a spray with a specific ellipticity ratio, similar to that described in the ’489 Patent ('353 Patent, col. 15:1-20).
Asserted Claims: At least claim 1 (Compl. ¶116).
Accused Features: The administration of the Perrigo ANDA Product into a nose via an actuator tip as a spray with the claimed ellipticity ratio, which the complaint alleges will be encouraged by Perrigo's product labeling (Compl. ¶117, ¶121, ¶125).

U.S. Patent No. 8,940,714 - "Cyanocobalamin Low Viscosity Aqueous Formulations for Intranasal Delivery"

Patent Identification: U.S. Patent No. 8,940,714, issued January 27, 2015.
Technology Synopsis: This patent claims a pharmaceutical composition with specific concentration parameters. It requires a pharmaceutically effective amount of cyanocobalamin at a concentration of about 0.5% of total weight, with low viscosity and a bioavailability of about 7% or more relative to an intramuscular injection containing cyanocobalamin at a 0.1% concentration ('714 Patent, col. 17:12-28).
Asserted Claims: 1 and/or 10 (Compl. ¶140).
Accused Features: The composition of the Perrigo ANDA Product, which is alleged to contain cyanocobalamin at about 0.5% concentration and meet the claimed viscosity and bioavailability requirements (Compl. ¶148-149).

U.S. Patent No. 9,415,007 - "Cyanocobalamin Low Viscosity Aqueous Formulations for Intranasal Delivery"

Patent Identification: U.S. Patent No. 9,415,007, issued August 16, 2016.
Technology Synopsis: This patent claims a method for treating a specific patient population. The method involves administering the aqueous solution to a subject having a vitamin B12 deficiency associated with gastric surgery ('007 Patent, col. 17:35-42).
Asserted Claims: 1 and/or 13 (Compl. ¶164).
Accused Features: The administration of the Perrigo ANDA Product to subjects with B12 deficiency associated with gastric surgery, an indication which the complaint alleges will be promoted by Perrigo's proposed label (Compl. ¶169-171).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendant Perrigo's proposed generic cyanocobalamin nasal spray, identified as the "Perrigo ANDA Product" (Compl. ¶6).

Functionality and Market Context

The Perrigo ANDA Product is described as a generic copy of Endo's Nascobal® nasal spray, intended for intranasal administration to treat Vitamin B12 deficiency (Compl. ¶6, ¶29). The complaint alleges, on information and belief, that the product is a kit comprising an aqueous solution of cyanocobalamin (500 mcg/spray) in a container with a droplet-generating actuator (Compl. ¶68, ¶70). By filing an ANDA, Perrigo seeks FDA approval to market this product as a therapeutically equivalent alternative to Nascobal®, thereby positioning it to compete directly with Endo's branded product upon approval (Compl. ¶7, ¶32).
No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'636 Patent Infringement Allegations

| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|:---------------------------------------------|:-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| A stable pharmaceutical aqueous solution comprising cyanocobalamin, water... | The Perrigo ANDA Product is alleged to be a stable pharmaceutical aqueous solution comprising cyanocobalamin and water. | ¶42 | col. 3:50-53 |
| a preservative selected from the group consisting of benzyl alcohol, parabens thimerosal, chlorobutanol, benzethonium chloride, and benzalkonium chloride... | The Perrigo ANDA Product is alleged to contain a preservative selected from this group. | ¶42 | col. 5:36-40 |
| a buffer selected from the group consisting of citric acid, sodium citrate... | The Perrigo ANDA Product is alleged to contain a buffer selected from this group. | ¶42 | col. 5:17-21 |
| and a humectant selected from the group consisting of sorbitol, propylene glycol, and glycerin... | The Perrigo ANDA Product is alleged to contain a humectant selected from this group. | ¶42 | col. 5:30-34 |
| wherein said solution... has a viscosity less than about 1000 cPs... | The Perrigo ANDA Product is alleged to have a viscosity less than about 1000 cPs. | ¶42 | col. 3:51-53 |
| and wherein said solution... has a bioavailability of cyanocobalamin when administered intranasally of at least about 7% relative to an intramuscular injection... | The Perrigo ANDA Product is alleged to have a bioavailability of at least about 7% relative to an intramuscular injection. | ¶42 | col. 3:53-56 |
| with the proviso that the solution contains no mercury or mercury compounds... | The Perrigo ANDA Product is alleged to contain no mercury or mercury compounds. | ¶42 | col. 3:55-56 |

'489 Patent Infringement Allegations

| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|:---------------------------------------------|:-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| A pharmaceutical kit for nasal drug delivery comprising: an aqueous solution of cyanocobalamin and excipients in a container... | The Perrigo ANDA Product is alleged to be a kit for nasal drug delivery comprising an aqueous solution of cyanocobalamin in a container. | ¶70 | col. 7:11-14 |
| and a droplet-generating actuator attached to said container and fluidly connected to the cyanocobalamin solution... | The Perrigo ANDA Product is alleged to include a droplet-generating actuator attached to the container. | ¶70 | col. 7:15-18 |
| wherein said actuator produces a spray... through a tip of the actuator when said actuator is engaged... | The Perrigo ANDA Product's actuator is alleged to produce a spray through its tip when engaged. | ¶70 | col. 7:19-21 |
| wherein said spray... has a spray pattern ellipticity ratio of from about 1.0 to about 1.4 when measured at a height of 3.0 cm from the actuator tip. | The Perrigo ANDA Product's spray is alleged to have a spray pattern ellipticity ratio of from about 1.0 to about 1.4 when measured at a height of 3.0 cm. | ¶70 | col. 7:21-26 |

Identified Points of Contention

Technical Questions: The complaint alleges on "information and belief" that the Perrigo product meets specific quantitative limitations. The central dispute will likely involve factual, evidence-based questions: Does testing of the Perrigo ANDA Product confirm that it has a viscosity below 1000 cPs? Does pharmacokinetic data show it achieves a bioavailability of "at least about 7%" relative to an intramuscular injection? Does testing of the delivery device confirm it produces a spray with an "ellipticity ratio of from about 1.0 to about 1.4"?
Scope Questions: The interpretation of the term "about" preceding numerical limitations (e.g., "about 1000 cPs," "about 7%") may become a key point of contention. The litigation may raise the question of how much variance from the stated numbers is permissible under the term "about" and whether the Perrigo product falls within that scope.

V. Key Claim Terms for Construction

The Term: "bioavailability ... of at least about 7% relative to an intramuscular injection of cyanocobalamin" ('636 Patent, cl. 1)
Context and Importance: This is a functional, performance-based limitation central to the '636 Patent's composition claims. Infringement depends on whether the accused product achieves this performance benchmark. Practitioners may focus on this term because if the accused product's measured bioavailability is close to but slightly below 7%, the construction of "about" and the methodology for measurement could be dispositive.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification repeatedly uses "about" when discussing bioavailability, including "at least about 8%, more preferably at least about 9, 10, 11, or 12%" ('636 Patent, col. 3:59-62). This could support an argument that 7% is not a rigid floor but an approximation.
- Evidence for a Narrower Interpretation: Example 1 in the patent details a specific clinical study protocol for measuring pharmacokinetic parameters and comparing intranasal to intramuscular administration ('636 Patent, col. 8:11-col. 10:67). A party may argue this detailed example defines the specific methodology required to assess whether a product meets the claim limitation.
The Term: "spray pattern ellipticity ratio" ('489 Patent, cl. 1)
Context and Importance: This term defines a specific geometric property of the spray produced by the delivery device. As it is a quantitative limitation, its precise definition and method of measurement are critical to determining infringement for the kit and method claims.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent's general description focuses on the overall goal of producing a spray that effectively deposits on the nasal mucosa, which could support an argument that minor deviations from the 1.0-1.4 range that still achieve this goal are equivalent ('489 Patent, col. 6:15-34).
- Evidence for a Narrower Interpretation: The patent provides a specific definition: "the ratio of the major axis to the minor axis" ('489 Patent, col. 6:52-53). Furthermore, Example 4 provides a concrete measurement of 1.14 using a specific test apparatus and methodology ('489 Patent, col. 15:55-col. 16:14). A party may argue that this specific definition and test method strictly define the scope of the term.

VI. Other Allegations

Indirect Infringement: The complaint alleges inducement of infringement for the asserted method claims (e.g., from the '353, '714, and '007 Patents). The basis for this allegation is that Perrigo’s proposed product label for its ANDA product will instruct and encourage end-users to administer the product in a manner that directly performs the steps of the patented methods (Compl. ¶43, ¶47-48, ¶97-98, ¶121-122, ¶145-146, ¶169-170).
Willful Infringement: The complaint does not contain a separate count for willful infringement. However, it alleges that Perrigo had knowledge of the patents-in-suit at least since the time it submitted its Paragraph IV Certifications to the FDA (Compl. ¶60, ¶82, ¶110, ¶134, ¶158, ¶182). The complaint also requests a declaration that the case is "exceptional" and seeks an award of attorney fees under 35 U.S.C. § 285, which often involves conduct similar to that supporting a willfulness claim (Compl. ¶53, ¶64, ¶75, etc.).

VII. Analyst’s Conclusion: Key Questions for the Case

A central issue will be one of factual proof and testing: As this case concerns a generic equivalent, the dispute will likely turn on whether empirical testing of Perrigo's ANDA Product confirms that it meets the specific, quantitative performance limitations recited in the patent claims, such as the minimum 7% relative bioavailability and the precise 1.0-1.4 spray pattern ellipticity ratio.
A secondary but potentially dispositive question will be one of definitional scope: How should the term "about," which precedes several key numerical limitations, be construed? The court's interpretation of the permissible variance allowed by this term could determine the outcome of infringement if the accused product's measured performance is close to, but not identical with, the claimed values.
Finally, a key issue for the litigation as a whole will be validity, as raised by Perrigo's Paragraph IV certification. The case will likely examine whether the patented invention—a low-viscosity aqueous solution achieving effective bioavailability—was obvious in light of prior art that allegedly taught that such formulations would be ineffective for intranasal Vitamin B12 delivery.