Details for Patent: 9,522,191
Which drugs does patent 9,522,191 protect, and when does it expire?
Patent 9,522,191 protects KARBINAL ER and is included in one NDA.
This patent has twenty-one patent family members in fourteen countries.
Summary for Patent: 9,522,191
| Title: | Modified release formulations containing drug—ion exchange resin complexes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Abstract: | An aqueous liquid suspension containing a coated drug-ion exchange resin complex comprising a core composed of an amphetamine complexed with a pharmaceutically acceptable ion-exchange resin and an uncoated amphetamine-ion exchange resin complex is provided. The coated amphetamine-ion exchange resin complex is in admixture with a polymer to form a matrix. Methods of making the coated complex and the liquid suspension are described. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Inventor(s): | Ketan Mehta, Yu-Hsing Tu | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Assignee: | Tris Pharma Inc | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Application Number: | US14/508,613 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Patent Litigation and PTAB cases: | See patent lawsuits and PTAB cases for patent 9,522,191 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Patent Claim Types: see list of patent claims | Compound; | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Patent landscape, scope, and claims: | US Patent 9,522,191: Scope, Claims, Exclusivity and Patent Landscape for Carbinoxamine Extended-Release SuspensionUS Patent 9,522,191 protects an oral liquid suspension containing carbinoxamine bound to a cation-exchange resin and coated with a cured polyvinyl acetate diffusion barrier. The strongest claims require a specific multiparticulate architecture, coating composition, plasticizer range, and modified-release function. The patent is a formulation and drug-delivery patent, not a carbinoxamine composition-of-matter patent. The commercial product most closely associated with the patent is KARBINAL ER, an extended-release oral suspension of carbinoxamine maleate marketed by Tris Pharma. The patent materially raises the barrier to a generic carbinoxamine extended-release suspension that uses the same resin-complex and polyvinyl acetate coating technology. It does not prevent all immediate-release carbinoxamine products, tablets, capsules, or extended-release products using materially different release technologies. What drug and product does US Patent 9,522,191 protect?The patent covers aqueous oral suspensions in which carbinoxamine is first bound to a water-insoluble cation-exchange resin. The resulting particles are optionally incorporated into a polymer-containing matrix and then coated with a water-insoluble, water-permeable, nonionic polymeric membrane. The claimed product has four technical elements:
The coating controls water penetration and drug diffusion from the resin complex. The product is administered as a liquid suspension rather than as a conventional tablet or capsule. KARBINAL ER is identified by FDA as carbinoxamine maleate extended-release oral suspension, 4 mg carbinoxamine maleate equivalent per 5 mL. The product is approved under NDA 022561 for allergic conditions, including allergic rhinitis and chronic urticaria indications described in the approved labeling. [2] What are the independent claims in US Patent 9,522,191?Claims 1, 15, and 18 are the principal independent claims. They pursue overlapping but different claim strategies.
Claim 15 is important because it does not require the polymer matrix in every embodiment. The claim permits an optional matrix but continues to require the specified polyvinyl acetate coating system. Claim 18 is structurally different. It requires a matrix and a defined coating quantity, but it does not repeat the detailed numerical coating-composition limitations found in claims 1 and 15. That makes claim 18 potentially broader in composition, although its enforceability would depend on construction of terms such as “high tensile strength,” “water permeable,” “modified release,” and the required relationship between the coating and the resin-complex matrix. How does claim 1 define the protected formulation?Claim 1 is a combination claim. Every material limitation must be present for literal infringement. Active pharmaceutical ingredientThe drug must be carbinoxamine. A product containing another antihistamine would not literally satisfy the carbinoxamine limitation, even if it used the same ion-exchange resin and coating system. Carbinoxamine must be bound to a pharmaceutically acceptable, water-insoluble ion-exchange resin. The claim specifies that the resin is a cation-exchange resin. A formulation using only a water-soluble excipient, an anion-exchange resin, or a nonionic adsorption material would present a nonliteral formulation profile. Particulate drug-resin matrixThe drug-resin complex must be in a matrix containing one of the following:
The matrix polymer must be present at about 3% to about 30% by weight based on the drug-resin complex matrix. Dependent claim 4 narrows this range to about 5% to about 20%. Claims 5 through 8 identify specific matrix configurations:
The matrix limitation creates a meaningful design-around route for a competitor that uses a resin complex without the claimed polymer matrix, although claim 15 may still apply because it permits the matrix to be optional. Diffusion-control coatingThe coating must be:
The coating must contain approximately:
Claim 10 narrows the plasticizer range to 5% to 10%, and claim 11 specifies triacetin. Claim 12 adds a surfactant. The coating is therefore more narrowly defined than a generic polymer membrane. A competitor could potentially avoid the literal scope by using another polymer family, a nonaqueous coating process, a coating outside the stated composition ranges, or a release-control mechanism that does not rely on the claimed cured polyvinyl acetate barrier. What dependent claim limitations matter most?The most commercially relevant dependent claims are claims 2, 6, 8, 11, 13, 14, 16, 17, and 19.
The mesh limitation in claim 3 is not a simple dosage-form limitation. It can affect particle-size distribution, sedimentation, mouthfeel, syringeability, and manufacturing yield. The elongation limitation in claim 2 may be difficult to assess from a finished product alone because it requires testing of the cured coating under defined conditions. What is the patent expiration date for US 9,522,191?The patent issued on December 20, 2016. Its U.S. filing and priority history place the nominal patent-term endpoint in approximately 2030, subject to patent-term adjustment, terminal disclaimers, and the precise USPTO term calculation. Public patent records identify June 30, 2030 as the operative projected expiration date for the patent family. [1]
The expiration date should be treated as a patent-term date, not as a guarantee that all claims remain enforceable until that date. Claim cancellation, disclaimer, invalidity, or a successful challenge could alter practical exclusivity. What is the Orange Book status of US 9,522,191?US 9,522,191 is associated with KARBINAL ER and is listed among the patents protecting the product in FDA Orange Book materials. The listing relates to the drug product’s extended-release oral suspension formulation, not to carbinoxamine generally. [2] An Orange Book listing can support a patent-infringement action against an ANDA applicant that files a Paragraph IV certification. It does not establish validity or infringement. The applicant can challenge the listed patent through litigation, and the patent holder must prove infringement if the dispute proceeds. The regulatory consequence of a Paragraph IV notice is generally a 30-month stay of FDA approval if the patent holder files a timely infringement action, subject to statutory exceptions and court action. The stay delays approval; it does not automatically extend patent term. [3] Have generic manufacturers filed Paragraph IV challenges?A complete current Paragraph IV and litigation determination requires review of the latest FDA Orange Book patent-certification information, ANDA litigation records, and PACER or district-court dockets. The supplied claim text does not establish whether a particular ANDA applicant has filed a Paragraph IV certification or whether litigation is pending. The relevant challenge would likely focus on one or more of the following:
A generic applicant could pursue a Paragraph III certification and wait for patent expiry, or file Paragraph IV certifications asserting invalidity, noninfringement, or both. A formulation with a different resin, a different membrane polymer, or a non-resin extended-release technology would have a stronger noninfringement position than a product closely replicating the KARBINAL ER architecture. What patent litigation affects KARBINAL ER and this patent?The central litigation risk is an ANDA action under the Hatch-Waxman statute if a generic applicant certifies that US 9,522,191 is invalid, unenforceable, or will not be infringed. The likely defendants would include the ANDA applicant and its relevant corporate affiliates; the plaintiff would be the patent owner or an exclusive licensee with standing. The patent record alone does not establish a completed judgment, settlement, license, or launch date. A settlement agreement could permit an authorized generic, a delayed generic launch, or a launch before patent expiry under negotiated conditions. No such commercial term should be inferred from the claims. How strong is the patent estate for carbinoxamine extended-release suspension?The estate is strongest against a formulation that copies the full technical architecture:
It is weaker against products using different release platforms.
The most important weakness is that the claims are highly formulation-specific. The same specificity that supports commercial protection can create invalidity and noninfringement pressure if the prior art discloses similar resin complexes, polymer coatings, or aqueous modified-release suspensions. What manufacturing and intellectual-property barriers does the patent create?The patent creates process-development barriers even where a competitor does not copy every claim limitation. A competing formulation must control:
A formulation can avoid literal infringement but still require substantial development work to match the reference product’s release profile and patient-use characteristics. Manufacturing know-how, analytical methods, batch records, and unresolved formulation trade secrets can therefore extend the practical barrier beyond the issued claims. Is there biosimilar risk for this patent?No conventional biosimilar risk exists. Carbinoxamine is a small-molecule antihistamine, and KARBINAL ER is regulated through the small-molecule drug pathway rather than the biologics license application pathway. The relevant competitors are ANDA applicants, not biosimilar applicants under the Biologics Price Competition and Innovation Act. The principal regulatory risk is generic substitution after patent expiry or after successful Paragraph IV litigation. How does US 9,522,191 compare with other carbinoxamine protections?
The patent does not claim every therapeutic use of carbinoxamine. Its protection depends on the product meeting the claimed physical and chemical formulation limitations. What generic launch scenarios exist?Three scenarios are commercially plausible. Launch after patent expiryA generic waits for the projected 2030 patent-term endpoint and files or maintains a Paragraph III position. This minimizes litigation risk but delays market entry. Paragraph IV challengeA generic asserts that the patent is invalid or not infringed. The patent owner may file an ANDA lawsuit, potentially triggering a 30-month stay. The result depends on claim construction, prior art, product testing, and the specific formulation disclosed in the ANDA. Non-infringing formulationA generic develops a different extended-release platform, such as a different resin, membrane polymer, or multiparticulate technology. This could reduce exposure to US 9,522,191 but would require independent demonstration of equivalent release, stability, dose uniformity, and suspension performance. What are the geographic limits of the patent?US 9,522,191 is enforceable only in the United States. It does not create patent rights in Canada, Europe, Japan, or other markets. Foreign counterparts, national-phase filings, prosecution outcomes, and expiration dates must be assessed separately. A product manufactured outside the United States can still create U.S. infringement exposure if it is imported into the United States or supplied for U.S. commercial distribution. The U.S. patent does not independently control foreign sales. Key Takeaways
FAQsCan a generic use carbinoxamine without infringing US 9,522,191?Yes. The patent does not claim carbinoxamine in all forms. A product that lacks the claimed resin-complex and modified-release coating architecture may avoid literal infringement. Does using polyvinyl acetate automatically infringe the patent?No. Polyvinyl acetate alone is insufficient. Infringement would depend on the complete combination, including the resin complex, coating structure, PVP stabilizer, plasticizer, application method, and other claim limitations. Does US 9,522,191 cover KARBINAL ER’s approved indication?The patent principally covers the product formulation. It is not limited to a single allergic-disease indication in the claims supplied. Regulatory labeling and patent claim scope are separate issues. Could a generic launch before 2030 without a Paragraph IV challenge?A generic could potentially launch after a successful noninfringement or invalidity determination, under a settlement or license, or with a formulation outside the patent claims. Commercial launch would also depend on FDA approval and applicable Orange Book certifications. Is the patent stronger against a liquid or a tablet generic?The patent is strongest against an aqueous liquid suspension that uses the claimed particulate resin-complex and polyvinyl acetate membrane. A tablet, capsule, or unrelated liquid release system presents a different infringement analysis. References
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Drugs Protected by US Patent 9,522,191
| Applicant | Tradename | Generic Name | Dosage | NDA | Approval Date | TE | Type | RLD | RS | Patent No. | Patent Expiration | Product | Substance | Delist Req. | Patented / Exclusive Use | Submissiondate |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Aytu | KARBINAL ER | carbinoxamine maleate | SUSPENSION, EXTENDED RELEASE;ORAL | 022556-001 | Mar 28, 2013 | RX | Yes | Yes | ⤷ Start Trial | ⤷ Start Trial | Y | ⤷ Start Trial | ||||
| >Applicant | >Tradename | >Generic Name | >Dosage | >NDA | >Approval Date | >TE | >Type | >RLD | >RS | >Patent No. | >Patent Expiration | >Product | >Substance | >Delist Req. | >Patented / Exclusive Use | >Submissiondate |
International Family Members for US Patent 9,522,191
| Country | Patent Number | Estimated Expiration | Supplementary Protection Certificate | SPC Country | SPC Expiration |
|---|---|---|---|---|---|
| Austria | E536867 | ⤷ Start Trial | |||
| Australia | 2007227569 | ⤷ Start Trial | |||
| Brazil | PI0709606 | ⤷ Start Trial | |||
| Canada | 2645855 | ⤷ Start Trial | |||
| >Country | >Patent Number | >Estimated Expiration | >Supplementary Protection Certificate | >SPC Country | >SPC Expiration |
