Details for Patent: 10,952,998
Which drugs does patent 10,952,998 protect, and when does it expire?
Patent 10,952,998 protects KATERZIA and is included in one NDA.
This patent has seven patent family members in four countries.
Summary for Patent: 10,952,998
| Title: | Amlodipine formulations | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Abstract: | Provided herein are stable amlodipine oral liquid formulations. Also provided herein are methods of using amlodipine oral liquid formulations for the treatment of certain diseases including hypertension and Coronary Artery Disease (CAD). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Inventor(s): | Scott BRAUER, Gerold L. Mosher | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Assignee: | Azurity Pharmaceuticals Inc | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Application Number: | US16/927,678 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Patent Litigation and PTAB cases: | See patent lawsuits and PTAB cases for patent 10,952,998 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Patent Claim Types: see list of patent claims | Formulation; Compound; | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Patent landscape, scope, and claims: | US Patent 10,952,998: Amlodipine Oral Liquid Formulation Scope, Claims, Exclusivity, and Competitive Patent LandscapeUS Patent 10,952,998 protects two formulation platforms: an amlodipine benzoate oral liquid and an amlodipine naphthalene-2-sulfonate oral liquid. The principal commercial protection is not directed to amlodipine itself. It is directed to a defined combination of salt form, pH control, sodium counterion source, suspension system, antifoaming agent, surfactant, water, and long-term chemical stability. The strongest claim coverage is concentrated in claims 1 and 20. Claim 1 requires storage stability at 5±5°C, while claim 20 requires stability at 25±5°C. The patent therefore reaches both refrigerated and room-temperature liquid formulations, but through different amlodipine salt systems. What does US Patent 10,952,998 protect?The patent protects oral liquid formulations containing amlodipine at a concentration corresponding to 1.0 mg/mL of amlodipine freebase. It does not broadly cover every liquid amlodipine product. The two independent claims are:
Both independent claims require:
The claimed invention therefore combines formulation composition with an objective stability result. A competing formulation may avoid literal infringement by changing any required element, including the salt, counterion concentration, simethicone level, pH range, suspension aid, drug concentration, or applicable stability profile (U.S. Patent No. 10,952,998, 2021). How broad are the claims of US 10,952,998?Claim 1: amlodipine benzoate formulationClaim 1 is a closed combination claim. A formulation must contain each recited component. The claim does not require a particular flavor, sweetener, manufacturing process, dosage container, or route other than oral liquid administration. The suspension aid Markush group covers:
The claim is materially broader than a single commercial recipe because it permits alternative suspension systems. Claims 15 and 16 narrow this coverage to two commercially relevant combinations:
Claims 12 through 14 add concentration-based limitations. They cover suspension-aid levels of 5-15 mg/mL, 3-10 mg/mL, or 20%-50% by weight of the suspension solids. Claims 12 and 13 overlap substantially. A formulation satisfying 5-10 mg/mL may fall within both dependent claims. Claim 20: amlodipine naphthalene sulfonate formulationClaim 20 establishes a separate formulation genus. It replaces benzoate with amlodipine naphthalene sulfonate and replaces sodium benzoate with sodium naphthalene-2-sulfonate. The claim also differs in three commercially significant respects:
This room-temperature stability limitation could be difficult to satisfy in litigation unless the accused product has comparable stability data or the patent owner can establish that the limitation is inherent in the accused formulation. What do the in-situ salt-formation claims cover?Claims 2-5 and 21-24 protect in-situ formation of the active salt during manufacture or formulation. For the benzoate platform, the claims cover reacting a more water-soluble pharmaceutically acceptable amlodipine salt with a molar excess of sodium benzoate. Claim 5 specifically identifies amlodipine besylate as the starting salt. For the naphthalene sulfonate platform, claims 21-24 apply the same concept using sodium naphthalene-2-sulfonate. The listed starting salts include:
These claims create process-linked product coverage. A generic manufacturer could face risk even if it does not purchase amlodipine benzoate or amlodipine naphthalene sulfonate as an isolated raw material. If its process converts amlodipine besylate into the claimed salt in the presence of excess sodium benzoate or sodium naphthalene-2-sulfonate, the process and resulting formulation may fall within the dependent claims. The phrase “formed in situ” creates an evidentiary issue. Detection of the final salt, residual starting salt, counterion balance, process records, and manufacturing batch controls may become relevant in an infringement investigation. What formulations are protected by the dependent claims?
Claims 6-8 are commercially relevant because pediatric oral liquids commonly use flavoring and sweetening systems. They are narrower than claim 1 and may provide fallback positions if a broader claim is challenged. Claim 19 extends the refrigerated stability period from at least 12 months to at least 24 months. It can be important for products marketed with two-year refrigerated dating, but it does not independently protect a formulation that fails the underlying composition and stability limitations of claim 1. When does US Patent 10,952,998 lose exclusivity?The patent’s enforceable expiration date cannot be calculated reliably from the issued patent number or claim text alone. The controlling date depends on the patent’s earliest effective nonprovisional priority date, any terminal disclaimer, patent-term adjustment, patent-term extension, and maintenance-fee status. The issued patent date is March 23, 2021. The ordinary patent term generally runs 20 years from the earliest effective nonprovisional filing date, subject to statutory adjustments (35 U.S.C. §§ 154, 156). A complete exclusivity analysis must distinguish:
Patent expiration also does not automatically establish immediate generic entry. A generic applicant may launch after patent expiration, after a settlement date, after a successful Paragraph IV challenge, or subject to a covenant not to sue. What is the FDA regulatory status of the protected formulation?Amlodipine is an established small-molecule calcium-channel blocker. FDA-approved products include tablets and liquid products. Liquid formulations are generally regulated through an abbreviated new drug application if the product can meet applicable sameness and bioequivalence requirements, or through a new drug application where formulation, dosing, or product-specific requirements differ (FDA, n.d.-a). The patent claims are formulation claims, not claims to the antihypertensive mechanism or the amlodipine molecule. A generic applicant therefore may need to address the patent estate even if it relies on the same active ingredient and therapeutic indication. FDA approval and patent enforceability are separate issues. FDA approval does not invalidate a patent, and patent expiration does not guarantee approval. What is the Orange Book status of US Patent 10,952,998?The Orange Book lists patents submitted by NDA sponsors for approved drug products and identifies relevant patent-use codes where applicable. Formulation patents may be listed if they meet FDA listing requirements, but the Orange Book is not a complete registry of every patent that could be asserted against a product (FDA, n.d.-b). The claim set supplied for US 10,952,998 is directed primarily to composition and formulation features. It does not contain a conventional method-of-use claim for treating hypertension or coronary artery disease. The likely regulatory relevance is therefore a drug-product or formulation patent listing rather than a use-code patent. A current Orange Book determination requires checking:
The claim text alone does not establish that the patent is currently listed in the Orange Book. Which companies are challenging the patent?No Paragraph IV challenger, ANDA number, district-court case, or settlement agreement can be established from the supplied claim text. The patent itself does not identify a generic challenger. For this patent, a Paragraph IV analysis would focus on whether an ANDA applicant argues that:
A certification against a patent can produce Hatch-Waxman litigation under 21 U.S.C. § 355(j), but the existence of the patent does not prove that litigation has occurred. How strong is the patent estate for amlodipine oral liquids?The claim structure is strongest against close copies of the protected suspension platform. A product that reproduces the commercial architecture, including 1 mg/mL amlodipine, pH 5-6, sodium benzoate, microcrystalline cellulose/sodium carboxymethyl cellulose, simethicone, polysorbate 80, and comparable stability, presents substantial literal infringement risk if the relevant patent rights remain enforceable. The estate is weaker against design-around formulations that use:
Principal validity pressure pointsThe claims may attract validity challenges on several grounds:
These are risk factors, not determinations of invalidity. How does the patent compare with competing amlodipine liquid products?KaterziaKaterzia is an amlodipine besylate oral suspension marketed at 1 mg/mL. Its publicly identified formulation characteristics are closely aligned with the type of product addressed by the claims, including suspension excipients and pediatric-liquid use. The key infringement question is whether the marketed product contains or forms the claimed amlodipine benzoate system, rather than simply whether it contains amlodipine besylate. NorliqvaNorliqva is an amlodipine besylate oral solution. A solution may avoid claims requiring a suspension aid or a suspension dosage form, but the analysis depends on the precise formulation and whether the product contains the claimed excipients and salt-conversion chemistry. FDA product labeling is the primary source for the marketed dosage form and inactive ingredients (FDA, n.d.-c). Generic amlodipine tabletsConventional amlodipine besylate tablets generally do not practice the claimed oral-liquid formulation limitations. They may still compete commercially but are not direct formulation substitutes for a pediatric or swallowing-impaired patient population.
What generic launch scenarios exist?Scenario 1: Paragraph IV launch before patent expirationA generic applicant could file an ANDA with a Paragraph IV certification and argue noninfringement or invalidity. The NDA holder could sue within the statutory period, potentially triggering a 30-month stay under the Hatch-Waxman framework, subject to statutory exceptions and court action. Scenario 2: Formulation design-aroundA competitor could avoid the claimed combination by using a different salt, non-listed suspension aid, alternative antifoaming system, different concentration, or a pH outside the claimed range. The commercial challenge is preserving taste, redispersibility, dose uniformity, chemical stability, and pediatric acceptability. Scenario 3: Post-expiration launchA generic could wait until expiration or settlement-permitted entry. This reduces litigation exposure but delays market entry and may allow the incumbent to establish switching relationships with prescribers and pharmacies. Scenario 4: Alternative dosage formA solution, tablet, capsule, or orally disintegrating product may avoid the claim set but may not be therapeutically or commercially equivalent to a 1 mg/mL pediatric suspension. What manufacturing and IP barriers remain?The principal technical barrier is simultaneous control of:
The in-situ conversion claims may increase switching costs because a competitor cannot necessarily avoid the patent by beginning with a different amlodipine salt if the final process uses the claimed counterion reaction. Geographically, US Patent 10,952,998 provides United States rights only. Separate foreign patent families, national-phase applications, continuations, and granted counterparts must be analyzed independently. A US design-around does not determine freedom to operate in Europe, Canada, Japan, China, or other markets. Key Takeaways
Frequently Asked QuestionsDoes US 10,952,998 cover amlodipine besylate itself?No. The claims cover specified oral liquid formulations and, in dependent claims, processes that convert a more soluble amlodipine salt such as amlodipine besylate into the claimed benzoate or naphthalene sulfonate system. Does a liquid amlodipine product infringe merely because it contains sodium benzoate?No. The product must satisfy all limitations of an asserted claim, including the amlodipine form, concentration, pH, suspension aid, simethicone, water, and stability requirements. Can a competitor avoid the patent by using amlodipine besylate?Possibly, but not automatically. If the manufacturing process uses excess sodium benzoate to form amlodipine benzoate in situ, claims 3-5 may remain relevant. Is a room-temperature amlodipine suspension covered by claim 1?Claim 1 requires stability at 5±5°C. A room-temperature product may also satisfy that limitation if it is stable under the claimed refrigerated condition, but it must meet every other limitation of the claim. Are there biosimilar issues for this patent?No conventional biosimilar pathway applies. Amlodipine is a small molecule regulated through generic-drug and NDA pathways rather than the biologics licensing framework. ReferencesFood and Drug Administration. (n.d.-a). Abbreviated new drug application (ANDA): Generics. https://www.fda.gov/drugs/types-applications/abbreviated-new-drug-application-anda Food and Drug Administration. (n.d.-b). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book-data-files Food and Drug Administration. (n.d.-c). Norliqva and amlodipine product labeling. U.S. Department of Health and Human Services. https://www.accessdata.fda.gov/scripts/cder/daf/ United States Code. (2024). 35 U.S.C. §§ 154, 156. https://uscode.house.gov/ United States Patent No. 10,952,998. (2021). Oral liquid formulations comprising amlodipine salts. U.S. Patent and Trademark Office. https://patents.google.com/patent/US10952998B2/en More… ↓ |
Drugs Protected by US Patent 10,952,998
| Applicant | Tradename | Generic Name | Dosage | NDA | Approval Date | TE | Type | RLD | RS | Patent No. | Patent Expiration | Product | Substance | Delist Req. | Patented / Exclusive Use | Submissiondate |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Azurity | KATERZIA | amlodipine benzoate | SUSPENSION;ORAL | 211340-001 | Jul 8, 2019 | 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 10,952,998
| Country | Patent Number | Estimated Expiration | Supplementary Protection Certificate | SPC Country | SPC Expiration |
|---|---|---|---|---|---|
| Canada | 3038989 | ⤷ Start Trial | |||
| European Patent Office | 3522872 | ⤷ Start Trial | |||
| European Patent Office | 3960158 | ⤷ Start Trial | |||
| European Patent Office | 4585213 | ⤷ Start Trial | |||
| Spain | 2886067 | ⤷ Start Trial | |||
| Spain | 3035030 | ⤷ Start Trial | |||
| >Country | >Patent Number | >Estimated Expiration | >Supplementary Protection Certificate | >SPC Country | >SPC Expiration |
