Last updated: April 26, 2026
CN102883601 is a Chinese patent publication that discloses a small-molecule drug invention and builds claim coverage around (i) a defined chemical scaffold and (ii) drug-related compositions and/or uses tied to that scaffold. Based on the available publication-level information for CN102883601, the invention’s legal scope is anchored to the claim-defined compound(s) and to claim-dependent territory that typically extends to pharmaceutical compositions and methods of treatment using those compounds.
What does CN102883601 claim, and where is the boundary of scope?
1) Claim architecture that defines the scope
CN102883601 follows the common Chinese practice of splitting protection into:
- Independent compound claims: the core inventive concept is the chemical structure(s) and/or genus definitions (e.g., substituent ranges) that define the “covered compound set.”
- Independent/secondary protection for drug application (often): pharmaceutical compositions and/or therapeutic use claims that tie the compound set to a medical indication.
- Claim-dependent refinements: narrowing by specific substituents, salts, hydrates, polymorphs, dosage forms, or administration regimens.
Practical boundary: If a product or R&D candidate does not fall inside the chemical definitions of at least one independent claim (or inside a narrowed dependent claim that matches its exact substituent/polymorph/salt definition), it sits outside CN102883601’s enforceable core. If it matches compound scope, the next gate is whether the product is marketed or used in the claimed way (composition/use/regimen scope).
2) Scope drivers inside compound claims
For Chinese filings like CN102883601, the most common scope drivers that determine infringement and design-around risk are:
- Genus vs. sub-genus language (broad variable definitions vs. enumerated structures)
- Substituent constraints (allowed groups, attachment points, and number limits)
- Connection topology (ring fusion, linker positions, stereochemistry, ring valence constraints)
- Salts/polymorph handling (whether salts/hydrates are explicitly claimed)
Design-around lever: substitute outside a restricted variable list (substituent scope is usually the main “pressure point” in structure-based claim sets).
3) Scope drivers inside composition and use claims
When CN102883601 includes pharmaceutical composition or method-of-treatment claims, the coverage boundary typically depends on:
- Composition claim constraints: excipient lists, ratios, or essential components
- Therapeutic use definition: indication wording (disease category, patient population) and whether the claim requires a particular therapeutic endpoint
- Dosing regimen: dose ranges and administration schedule, if included
Infringement gate: even a covered compound may fall outside if the product is not formulated/used in the manner required by the composition/use claim language.
What does CN102883601 protect in the compound space?
1) Compound set protected by the independent claims
CN102883601’s compound protection is centered on the chemical definitions recited in the independent claim(s). In practice, you can treat the independent claim(s) as defining:
- a core scaffold (the portion that is almost always fixed), and
- a set of permitted substituent positions and group selections (the portion that varies).
Key analytical consequence: most “near-miss” design changes target the permitted substituent groups and/or stereochemical definitions. If the independent claim defines stereochemistry or a specific isomer, switching to a different stereoisomer can avoid coverage even when the overall scaffold matches.
2) Salts and solvates
If the claims include salts (and/or hydrates/solvates) of the claimed compound, enforcement can extend to marketed salt forms even when the base free form differs. Where salts are not explicitly included, salt switching can be a real design-around route.
3) Polymorph handling
Many Chinese chemical patents either:
- explicitly claim specific crystalline forms, or
- remain at the compound/genus level only.
If CN102883601 only claims the compound definition without explicit polymorph forms, polymorph switching has less leverage. If polymorph forms are claimed, then only the claimed forms remain exposed.
What is the practical claim coverage for product development and freedom-to-operate (FTO)?
1) Likely FTO exposure profile
For CN102883601, FTO risk generally clusters into four categories:
- Direct compound coverage: your active ingredient matches the independent claim chemical definitions.
- Salt/form coverage: your marketed salt matches a claimed salt definition tied to the same core compound.
- Formulation coverage: your dosage form matches a claimed composition claim (if present).
- Use coverage: your label indication matches the claimed therapeutic use.
2) Highest-risk areas to check against CN102883601
- Core scaffold match: does the chemical core match the independent claim scaffold?
- Variable substituent match: do all variable groups fall within the allowed definitions?
- Stereochemistry: does the filing require an absolute/relative configuration or specific isomer?
- Salt/form: is your drug a specific claimed salt or polymorph?
- Indication and method: does your label or off-label development plan match the claimed use?
How does CN102883601 sit in the China patent landscape?
1) Landscape structure: primary patent layer vs. follow-on layers
In China, drug patent landscapes around small molecules typically show this pattern:
- Primary compound patent(s): CN102883601 likely represents the original compound disclosure layer.
- Secondary layers: later patents add improvements such as salt forms, polymorphs, specific formulations, dosing regimens, or combination therapies.
- Regulatory exclusivity interaction: patent enforcement interacts with regulatory data and marketing authorization practices, but the enforceability and coverage still map to claim scope and claim validity.
2) Expected competitive adjacency
For a given compound-genus patent, the most common adjacency patents in the same family or in competitor portfolios include:
- Salt/hydrate polymorph patents (often filed as separate Chinese publications)
- Crystalline form patents for commercial solid state forms
- Formulation patents (tablet, capsule, controlled release)
- Method-of-use patents (new indication, new dosing schedule)
- Combination patents (co-administration with another active)
Business implication: even if CN102883601 is not the only relevant barrier, it often defines the “first wall” around the compound core; follow-on patents can block the commercial path even after compound-level clearance.
3) Claim-strength sensitivity in this landscape
Enforcement outcomes in China are claim-sensitive. If CN102883601 includes:
- broad genus claims, then validity challenges often target lack of enablement or overbreadth.
- narrow specific claims, then competitive avoidance becomes a question of exact structural and form matching.
What are the key claim elements you should map for infringement risk?
1) Claim mapping checklist (what you match to CN102883601 language)
- Chemical structure: core scaffold and each variable position.
- Substitution limits: allowed substituent groups at each position.
- Stereochemical requirements: configuration and isomer definitions.
- Salt/form: whether salts/polymorphs are explicitly claimed.
- Dosage/composition: excipients, ratio ranges, dosage form limitations.
- Use/regimen: indication language and whether it requires a defined dosing schedule.
2) Common “escape” routes that work against structure-anchored claims
- Substituent switch out of a constrained set
- Stereoisomer swap when claims require a specific isomer
- Non-claimed salt or non-claimed polymorph when forms are enumerated in claims
- Indication-based separation where the method-of-use claims are indication-limited
What is the likely status and enforcement relevance of CN102883601?
CN102883601 is a Chinese publication and functions as a prior art and rights basis depending on:
- its granted status (not inferable from the publication number alone without file data),
- claim scope as published and any amendments during examination,
- whether later events (reexamination/invalidations) affected enforceability.
For landscape work, the correct operational assumption is that CN102883601 is a meaningful reference point for compound-level coverage and family-based blocking, while follow-on patents determine how much commercial latitude remains for specific forms and indications.
Key Takeaways
- CN102883601’s scope is anchored in claim-defined chemical structures, with boundary set by variable substituent definitions, stereochemistry (if specified), and the claimed scaffold topology.
- If CN102883601 includes pharmaceutical composition and/or method-of-treatment claims, infringement depends not only on the active ingredient but also on product formulation and label/clinical use alignment with the claim wording.
- In China landscapes, compound patents like CN102883601 are typically the first barrier; follow-on patents often cover salts, polymorphs, formulations, dosing regimens, and combination use, shaping the real FTO path.
- The most effective design-around levers for structure-anchored claims are typically substituent and stereochemistry changes, then salt/polymorph selection, followed by indication/formulation separation when method-of-use coverage exists.
FAQs
1) Does CN102883601 protect only the compound, or also drug products?
It typically protects the claimed compound set and, when present in the claim set, also extends coverage to pharmaceutical compositions and therapeutic uses tied to that compound set.
2) If my active ingredient matches the scaffold, can I still avoid CN102883601?
Yes, if the competitor product differs in at least one of the independent claim boundaries such as variable substituent selections, stereochemistry, or claimed salt/polymorph/form definitions.
3) What matters most for FTO mapping against CN102883601?
The highest-leverage step is claim-by-claim mapping of your structure and product attributes to the independent claim chemical definitions, then validating whether your commercial product aligns with any composition/use/regimen limitations.
4) How does the patent landscape around CN102883601 usually evolve?
Landscapes commonly show additional filings around the same core compound: salts/polymorphs, formulations, dosing regimens, and new indications or combinations.
5) Is CN102883601 a blocking patent by itself?
It can be, but real-world commercial freedom is usually determined by the stack of related patents around the same active ingredient and its marketed form and indication, not by CN102883601 alone.
References
[1] CN102883601. Patent publication record, China National Intellectual Property Administration (CNIPA).
