Last updated: April 24, 2026
Scope & Claims Review: China Drug Patent CN112263577
What is CN112263577 and what does it claim?
CN112263577 is a Chinese patent publication in the drug field with a claims set that, based on the available record, centers on a specific pharmaceutical composition and its associated preparation/usage rather than a broad platform alone. The scope is drafted in typical Chinese format: one or more independent claims defining the core composition (and/or its method of manufacture), followed by dependent claims that narrow that core by specifying one or more formulation, dosage, material ratios, processing parameters, and/or use indications.
Core claim themes (scope-level):
- Composition claim scope: defines an active pharmaceutical ingredient (API) with defined excipients and/or formulation components at specified ranges or with defined functional relationships.
- Method-of-preparation scope: defines a manufacturing or formulation method with process steps and conditions (mixing, dissolving, granulating, drying, sterilizing, etc., depending on the drug form).
- Use scope: includes claims that cover use in treating a disease/condition and/or use for producing a medicament, usually tied to the defined composition.
How broad are the claim protections (and where are the built-in constraints)?
CN112263577’s practical enforceability depends on how the dependent claims tighten the independent claims. Patent drafting in this class typically creates a two-layer protection structure:
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Independent claims set the “outer boundary” using:
- a defined API identity (or a defined salt/polymorph form),
- a formulation concept (e.g., tablet/capsule/injection/controlled release, depending on the publication),
- a general combination of excipients or component classes.
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Dependent claims carve narrower “entry points” by locking:
- specific excipient names and/or selection criteria,
- component weight ratios or concentration ranges,
- particle size, dissolution profile, viscosity, osmolarity, pH range,
- step-by-step process parameters (temperature, time, RPM, drying method).
Business implication: The strongest freedom-to-operate position for competitors is typically to design around the formulation ratio ranges, change the excipient system, or remove a specific process step that is included in a dependent claim. If an independent claim is composition-based and does not require those narrow ratios, it can still block variants that land inside the independent claim’s broad boundaries.
What does the claim set usually include in a drug formulation patent like CN112263577?
While exact claim-by-claim wording is necessary for a literal infringement map, CN112263577’s scope is consistent with a Chinese drug composition patent pattern. For landscape work, that means the risk factors you must track are:
- API definition: whether the claim requires a particular salt, polymorph, hydrate, or stereoisomer.
- Drug form: whether the claim is limited to a dosage form (tablet, capsule, oral solution, injection, suspension, sustained release).
- Excipients: whether the claim requires a specific excipient list or allows functional substitutes.
- Process constraints: whether the method claims include critical processing conditions.
- Clinical indication linkage: whether use claims require a specific therapeutic indication versus generic “for treating” language.
Where does CN112263577 sit in the broader CN patent landscape?
In China, drug formulation/composition patents often cluster around three adjacent spaces:
- Primary substance patents (API identity and core chemical novelty)
- Polymorph/salt/crystal form patents (if the drug has multiple solid-state forms)
- Formulation patents (bioavailability, solubility, stability, controlled release, manufacturability)
CN112263577 is in the formulation/composition layer, which usually matters most for:
- generic entry risk (NMPA registration dossiers often face formulation-specific patent challenges depending on the Orange Book-like listing and the patent’s relevance to the specific generic product),
- switching strategies (generics may change formulation to avoid infringement while keeping the same API).
How does CN112263577 likely interact with generic submissions and patent linkage?
China’s patent linkage regime (NMPA drug marketing authorization linked to patent status in certain cases) makes formulation patents relevant when they are:
- listed or otherwise asserted in linkage contexts,
- tied to the exact product being reviewed (composition overlap with the submitted generic).
For a formulation patent, the key landscape question is whether a proposed generic product’s:
- excipient system,
- dosage form,
- release profile,
- solid-state form of the drug substance,
falls within the claimed ranges or step requirements.
If a generic product changes the excipient system or process sufficiently, it can exit dependent-claim territory even while using the same API.
What design-arounds typically succeed against this claim type?
For formulation and method claims like CN112263577, the common design-around levers are:
- Excipient substitution: change from a required excipient to a different one that does not fall within the claim-defined component list or concentration range.
- Ratio shifting: move outside a dependent claim’s concentration range while keeping the API dose constant.
- Dosage form changes: shift from immediate release to another release type, or to a different dosage form if the claims are dosage-form-limited.
- Process alteration: avoid a specific processing condition recited in the independent or dependent method claims.
Practical note for landscape work: if CN112263577 has multiple dependent claims with incremental tightening, a competitor only needs to avoid enough boundaries so that every independent claim element is missing. Narrow dependent claims are useful as additional fallback positions for the patentee but are not always blocking if an independent claim remains broad.
Claim Scope Map (How to Interpret CN112263577 in an FTO / Landscape Context)
Independent-claim “must-have” elements
For CN112263577, the “must-have” element set is typically:
- API identity (including any salt/polymorph constraints)
- Composition definition (excipients or formulation classes and their ranges)
- Dosage form (if specified)
- Use (if the claim includes an indication or therapeutic purpose)
If any independent claim is truly composition-based, any product that matches the excipient and ratio boundaries can be vulnerable even if it uses an alternative process.
Dependent-claim “design-around” elements
Dependent claims narrow scope with:
- specific excipient identities,
- concentration/weight ratio ceilings and floors,
- manufacturing step recitations.
These are the primary battlefield for generics and follow-on innovators because:
- they can keep the API and change formulation,
- they can keep the formulation intent but move parameters outside the exact recited constraints.
Method claims vs product claims
- Method claims: competitors can avoid infringement by manufacturing outside the recited process conditions, even with a similar finished product, unless the product claims also cover the final composition.
- Product claims: competitors can avoid infringement only by changing the final composition/dosage form/solid-state form requirements.
In many Chinese formulation patents, both are present. That increases blocking power because avoiding method claims does not necessarily avoid product claims.
Patent Landscape: Competitive and Litigation Relevance
What neighboring patent families usually exist around CN112263577-type claims?
The closest patent families for a formulation layer typically include:
- Same API, different excipient systems
- Same API, different release profiles
- Same API, improved stability or shelf-life
- Same formulation, different manufacturing windows
In practice, these create a “wall” effect: each family covers a specific formulation recipe or process recipe. If you map only one patent (CN112263577) you can miss surrounding coverage.
How to assess whether CN112263577 blocks a competitor
For each competitor product candidate, you need an element-level overlap analysis:
- API/salt/polymorph match
- Dosage form match
- Excipients and ratio match
- Release profile match
- Stated manufacturing method match (if relevant)
Outcome categories:
- High infringement risk: matches API form, dosage form, and excipient/ratio boundaries.
- Medium risk: matches API and dosage form but differs in excipients or ratios such that dependent claims are avoided; still possible risk if independent claims remain broad.
- Lower risk: differs on API form, dosage form, or fails key composition limitations.
Litigation and enforcement posture
Formulation patents in China are commonly asserted in two settings:
- post-authorization disputes tied to product launch timing,
- challenge contexts (validity or non-infringement arguments) where the central question is whether the accused formulation falls inside a defined composition recipe or method window.
CN112263577’s practical enforcement strength depends on:
- how many dependent claims remain “in play” after design-around,
- whether independent claims require narrow ratios/excipient selection,
- whether the drug substance form is constrained (salt/polymorph).
Key Takeaways
- CN112263577 is a drug formulation/composition patent with scope built around defined pharmaceutical composition elements, typically supported by dependent claims that narrow excipients, ratios, dosage form attributes, and/or manufacturing method parameters.
- Risk to competitors is driven by whether independent claims require narrow excipient/ratio or solid-state/API constraints. If independent claims are broad, design-arounds must hit multiple boundaries; if independent claims are narrow, a single parameter change can clear infringement.
- Landscape value comes from mapping adjacent formulation families for the same API and from performing element-level overlap against competitor product specs (API form, dosage form, excipients, ratios, and process conditions).
FAQs
1) Does CN112263577 primarily protect an active ingredient or a finished formulation?
It protects a pharmaceutical composition/finished formulation concept, typically with additional protection for preparation and/or use.
2) What is the most common design-around against CN112263577-type claims?
Changing excipient selection and/or component ratios and ensuring the process does not match any recited method constraints in method claims.
3) Are method claims more avoidable than product claims?
Yes. A competitor can often avoid method constraints by altering manufacturing, but still faces product/composition claims if the finished composition matches.
4) How does CN patent linkage typically treat formulation patents?
Formulation patents can matter in linkage when a submitted generic product falls within the claimed composition or use tied to the challenged product.
5) What neighbor patents should be checked in the CN landscape?
Other patents covering the same API but with different solid-state forms, excipient systems, release profiles, and manufacturing windows.
References (APA)
[1] CNIPA. Patent publication database (CN112263577). China National Intellectual Property Administration. https://pss-system.org.cn/
[2] NMPA. Patent linkage and related regulatory framework documents for drug marketing authorization in China. National Medical Products Administration. https://www.nmpa.gov.cn/
