PTAB

IPR2016-01111

DR Reddy's Laboratories Inc v. MonoSol RX LLC

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Uniform Films for Rapid Dissolve Dosage Form Incorporating Taste-Masking Compositions
  • Brief Description: The ’514 patent is directed to rapidly dissolving, thin-film drug delivery compositions for the oral administration of active pharmaceutical components. The invention focuses on manufacturing uniform films that incorporate taste-masking elements to ensure consistent dosing.

3. Grounds for Unpatentability

Ground 1: Claims 1-3, 9, 15, 62-65, 69-73, and 75 are obvious over Bess in view of Chen.

  • Prior Art Relied Upon: Bess (Patent 7,067,116) and Chen (International Publication No. WO 00/42992).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of Bess and Chen disclosed all key limitations of the challenged claims. Bess taught an orally dissolving film comprising a water-soluble polymer, a taste-masking agent, and a pharmaceutically active ingredient, including opioids. Chen taught cast films containing various polymers and active agents, the use of viscosity to ensure a homogenous formulation, and taste-masking via encapsulation. The central disputed limitation, a drug content variation of less than 10%, was argued to be inherently disclosed. Petitioner asserted that Bess disclosed a weight variance of approximately 4% (70 ± 3 mg), and Chen's disclosed process controls (e.g., viscosity of 500-15,000 cps) and quality data (e.g., weight variation of 0.028 ±0.001 and dissolution data) demonstrated that the resulting films would necessarily meet the claimed uniformity.
    • Motivation to Combine: A POSITA would combine Bess's teachings on fast-dissolving films with Chen's detailed methods for creating homogenous, taste-masked film formulations. The motivation stemmed from the well-established need to meet regulatory requirements for dose uniformity, ensure patient safety, and avoid product recalls, all of which mandate producing dosage forms with minimal drug content variation.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because both references taught the fundamental components and methods for producing uniform films. Chen's disclosure of specific viscosity ranges and controlled drying processes provided a clear roadmap for achieving the claimed uniformity with only routine optimization.
    • Key Aspects: Petitioner argued that the PTAB, in three prior reexaminations of related patents, had already found that Chen discloses substantial uniformity, and that collateral estoppel should preclude the Patent Owner from re-litigating this issue.

Ground 2: Claims 1-3, 9, 15, 62-65, 69-73, and 75 are obvious over Chen in view of Cremer.

  • Prior Art Relied Upon: Chen (International Publication No. WO 00/42992) and Cremer (CA 2,274,910).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground relied on Chen for the primary teachings of cast films with controlled viscosity, taste-masking agents, and various active ingredients. Cremer was introduced for its disclosure of flat, water-soluble drug delivery preparations containing actives like buprenorphine. Critically, Cremer taught that a film's "homogenous thickness, density and width" leads to a "direct relation" between a unit of length of the film and the dose of the active substance contained therein. Petitioner argued this explicit teaching of homogeneity directly supported the achievement of the claimed <10% drug content uniformity limitation when combined with Chen's methods.
    • Motivation to Combine: A POSITA would combine Chen's detailed manufacturing processes with Cremer's teachings on water-soluble, mucoadhesive films to develop an effective oral dosage form. The explicit link in Cremer between physical homogeneity and dose uniformity would motivate a skilled artisan to apply Chen’s methods to achieve the predictable and consistent dosing required by regulatory standards.
    • Expectation of Success: The combination provided a high expectation of success. Chen supplied the "how"—specific process parameters like viscosity control to create a uniform suspension—while Cremer supplied the "why" and the result—explicitly linking physical uniformity to dose uniformity. This combination left no doubt that a uniform film with low dose variation was an achievable and predictable outcome.

4. Key Claim Construction Positions

  • "dried without the loss of substantial uniformity": Petitioner argued that this term should be given its broadest reasonable interpretation. Citing testimony from the Patent Owner's own expert in a related district court case, Petitioner contended the term is not limited to any specific form of drying or particular drying parameters. Therefore, it should be construed as "any method of drying," which would encompass the conventional drying methods disclosed in the prior art.

5. Key Technical Contentions (Beyond Claim Construction)

  • Viscosity as a Control for Uniformity: A central technical contention was that the role of viscosity in maintaining the stability and uniformity of suspensions was well-understood in the pharmaceutical arts at the time of the invention, citing principles such as Stoke's Law. Petitioner argued that Chen's disclosure of a specific viscosity range (500-15,000 cps) was not merely incidental but was a deliberate process parameter intended to prevent particle settling and aggregation during casting and drying. This understanding meant that Chen inherently taught the means to achieve the claimed uniformity, making the limitation obvious.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-3, 9, 15, 62-65, 69-73, and 75 of Patent 8,603,514 as unpatentable.