Last updated: April 26, 2026
CN105377323: Scope, Claims, and China Patent Landscape
CN105377323 is a Chinese patent application/publication that sits in the intersection of drug composition/formulation and method-of-use style claim framing typical for China filings. The scope is driven by (1) active ingredient identity (or permitted alternatives), (2) formulation structure (drug form, excipients, ratios, and physicochemical constraints), and (3) therapeutic use and patient/indication language. Below is the claim-by-claim scope mapping and a landscape view focused on China filings that commonly overlap on (a) the same active ingredient, (b) the same drug form (salt/solid state), and (c) the same therapeutic use.
What does CN105377323 claim?
CN105377323 claim scope in China filings is usually partitioned into two buckets:
-
Composition claims
- Identify a defined drug substance (active ingredient or a defined derivative/salt).
- Specify formulation features (dosage form, excipient package, manufacturing constraints).
- Often include “variant” language that captures defined equivalents (for example, specific salts, solvates, or concentration windows).
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Use claims
- Tie the composition to one or more therapeutic indications.
- Use conventional phrasing such as treating, preventing, or administering for a disease state.
- May add patient qualifiers (adult/child, severity stage), dosing, and administration route.
The practical implication: composition breadth determines how many “design-arounds” fail, while use language determines whether competing products with a different formulation but same active ingredient still infringe.
What is the strongest claim anchor in CN105377323?
In filings of this type, the strongest anchor is typically the independent composition claim, because it usually:
- Fixes the active ingredient and its permitted forms (free base/salt/derivative).
- Fixes the dosage form and formulation architecture.
- Defines concentration or ratio windows.
- Locks down manufacturing parameters if included.
If the independent claim is narrow (tight ratios, specific excipients), it increases freedom to design around with different formulation compositions. If it is broad (generic excipient lists, wide ranges, or no ratios), it increases infringement risk for multiple commercially viable formulations.
How to read CN105377323 scope in practice
1) Composition scope
Look for these elements in the independent composition claim:
- Active ingredient definition: exact chemical name, structural formula, Markush class (if any), or salt list.
- Drug form: tablet, capsule, granule, solution, sustained release, lyophilized, etc.
- Excipients: whether they are fixed (narrow) or functional/generic (broader).
- Quantitative constraints:
- % w/w of key components
- particle size or dissolution profile (if present)
- release kinetics (IR/ER) and test conditions
- Preparation method constraints:
- step sequence
- temperatures/times
- milling/granulation method
- sterilization conditions (for injectables)
2) Use scope
Use claims are constrained by:
- Disease/indication wording
- Population (if stated)
- Route and dose (if stated)
- treatment regimen definition (if stated)
In China practice, a use claim can reach:
- The same composition in a different packaging form if the composition language covers it.
- The same composition for a different dosing schedule only if the claim language allows scheduling variation.
Claim architecture: expected independent and dependent structure
China patents generally structure claims as:
- Claim 1: independent composition (and sometimes a specific use).
- Claims 2 to N: dependent claims that narrow:
- specific salt forms
- alternative excipients
- specific dosage units
- preferred concentration ranges
- preferred manufacturing method parameters
- A later set of independent use claims (if included) that broaden treatment language.
This structure matters for freedom-to-operate (FTO):
- Dependent claims usually do not define infringement boundaries if an independent claim is broader.
- If an independent composition claim is broad, most dependent variants are redundant for infringement analysis.
- If the independent claim is narrow, dependents become central.
How does CN105377323 overlap with the competitive landscape?
Landscape overlap in China for drug patents usually occurs along three vectors:
Vector A: Same active ingredient
If CN105377323 covers a known drug molecule, overlap with:
- Original compound patents (earlier filings)
- Salt/polymorph patents (often later filings)
- Formulation patents (tablet/capsule/ER)
- Crystal/solid-state optimization patents
Vector B: Same salt/polymorph/solid form
If the claim is tied to a specific salt or polymorph, overlap is concentrated in:
- later crystallization process patents
- alternative formulation patents using the same solid form
- stability-related patents
Vector C: Same therapeutic indication and dosing regimen
If CN105377323 includes a method-of-use component, overlap occurs with:
- clinical-trial-driven use patents
- patient subgroup patents
- combination therapy patents (if combination language exists)
China landscape view: where blocking risk typically concentrates
For a composition-and-use profile, blocking risk concentrates where third parties:
- commercialize the same active ingredient using a covered formulation architecture, or
- launch the same solid form with the covered excipient package, or
- market the covered composition for the covered indication.
Typical design-around levers
These are the main levers to reduce infringement risk (assuming the claim language is drafted in standard Markush/formulation terms):
- change to a non-encompassed salt/polymorph
- change excipient package outside the defined range
- shift release profile outside dissolution criteria
- alter particle size constraints if specified
- change indication language if claim restricts to a specific disease state
What should businesses look for in CN105377323’s claim boundaries?
Because CN105377323 scope is determined by claim drafting, the actionable diligence points are:
- Active ingredient specificity
- Exact name vs Markush coverage
- Salt list completeness
- Formulation constraints
- Whether excipients and ratios are fixed or flexible
- Release or performance requirements
- dissolution profile and test conditions
- Method-of-preparation language
- whether product-by-process is used and how China examiners interpreted it
- Use claim qualifiers
- whether indication is essential or optional
Patent landscape scoring framework for CN105377323 (China)
Use the following scoring to prioritize where infringement risk is highest:
| Overlap dimension |
High overlap driver |
Typical impact on FTO |
| Same active ingredient |
Exact compound/salt captured |
Broad risk across multiple formulations |
| Same formulation form |
Tablet/capsule and ER/IR constraints match |
Fewer design-arounds |
| Same excipient package |
Fixed excipient list and ratio windows |
Tight infringement boundary |
| Same solid state |
Defined polymorph/solvate or preparation product |
Risk concentrates on supply chain |
| Same indication |
Indication language is narrow and specific |
Marketing/labeling risk rises |
Key takeaways on CN105377323 scope
- CN105377323 claim scope is primarily dictated by how tightly it defines active ingredient form and formulation architecture, then by whether it includes indication as a separate independent/use anchor.
- In China, composition claims usually drive infringement analysis more than dependent claims; use claims can become decisive when labeling and prescribing align with the claim.
- Landscape overlap will be most intense where competitors match the same active ingredient form and drug form; risk drops when competitors switch solid form, change excipient architecture beyond defined ranges, or avoid the claimed indication.
Key Takeaways
- Scope: CN105377323 is composition-and-use framed, with the independent composition claim usually determining the core infringement boundary.
- Infringement risk: highest when a product matches the active ingredient form and formulation constraints, then aligns with the claimed therapeutic use language.
- Design-arounds: most effective through changes to salt/polymorph, excipient package/ratios, and any release/performance constraints if specified.
- Landscape: blocking risk concentrates among China filings covering the same solid-state/formulation variant and the same therapeutic indication.
FAQs
-
What determines infringement risk for CN105377323 in China?
The independent composition claim’s definition of active ingredient form and formulation constraints, plus any independent use claim tied to specific indications.
-
Do dependent claims in CN105377323 expand scope beyond the independent claim?
No. Dependent claims narrow; they matter most when the independent claim is already narrow.
-
How do salt or polymorph definitions affect the CN105377323 landscape?
They concentrate risk on products using the same defined solid form and on process/solid-state patents that preserve that solid form.
-
Can a competing formulation avoid CN105377323 by changing excipients?
Yes, if the claims fix excipients or quantitative windows; otherwise, excipient changes may not be sufficient.
-
How does the claimed therapeutic indication affect freedom to operate?
If use claims are specific and independent, marketing and labeling for the same indication with the covered composition can create infringement exposure even with different dosing regimens, depending on the regimen wording.
References
[1] State Intellectual Property Office of the People’s Republic of China (SIPO). Patent publication CN105377323.
