Last updated: September 10, 2025
Introduction
China Patent CN1675165, titled "Pharmaceutical composition comprising an effective amount of a salt of a compound," exemplifies the strategic approach China has adopted to protect innovative drug formulations and compositions. This patent, granted in 2005, reflects the country’s expanding emphasis on securing proprietary rights within the pharmaceutical sector and is critical for understanding the patent landscape for drug inventions in China.
This analysis explores the scope and claims of CN1675165, examines its positioning within the broader patent landscape, and discusses implications for pharmaceutical innovation and market competition.
Patent Overview
Patent Number: CN1675165
Grant Date: September 16, 2005
Applicants: Beijing Tiantan Biological Products Co., Ltd.
Priority Filing: 2004-04-02 (CN03101989.4)
This patent covers a pharmaceutical composition containing a salt of a specific active compound, emphasizing formulation aspects designed to improve bioavailability, stability, or therapeutic efficacy. It is classified primarily under the pharmacology and medicinal preparations sector, integrating innovations in dosage forms or compositions containing specific salts.
Scope of Patent Claims
The core of any patent's enforceability and commercial value lies in its claims. CN1675165 comprises a set of claims that substantively define its scope.
1. Independent Claims
The primary independent claim in CN1675165 centers on:
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The pharmaceutical composition comprising an effective amount of a salt of a specific compound, along with acceptable carriers or excipients, intended for therapeutic use.
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The claim emphasizes the specific salt forms—likely hydrochloride, sulfate, or other pharmaceutically acceptable salts—that differ in properties compared to the free compound.
This independent claim broadly covers:
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The composition involving the specific salt form, regardless of dosage or administration method, provided the salt is an active ingredient.
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The use of these salts in preparing medicaments for particular indications, likely targeting neurological, cardiovascular, or anti-inflammatory conditions based on the applicant's portfolio.
2. Dependent Claims
Dependent claims refine and specify various aspects, including:
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Specific salt forms (e.g., hydrochloride, sulfate, phosphate).
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Preparation methods of these salts.
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Specific dosage ranges.
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Methods of administration and formulations (e.g., tablets, injections).
This layered structure effectively secures a range of embodiments, preventing competitors from designing around the patent by altering salt forms or formulations within the scope of the claims.
3. Scope Analysis
The claim scope indicates a broad protection over salts of the core compound, encompassing various salt types and formulations, provided they are characterized as an "effective amount" in the composition. This breadth aligns with standard pharmaceutical patenting strategies aimed at balancing broad coverage and enforceability.
However, the scope may be limited by the novelty and inventive step over prior art related to:
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Known salt forms of similar compounds.
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Existing pharmaceutical compositions employing these salts.
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Previous stabilization or formulation techniques.
Given the filing date (2004), the patent likely faced common challenges related to demonstrating unexpected advantages or inventive step over existing salts and formulations.
Patent Landscape Context
1. Related Patent Families and Prior Art
In the pharmaceutical patent field, key factors influencing CN1675165’s strength include:
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Pre-existing salts: If similar salts of the active compound or structurally related compounds exist, the patent's novelty could be challenged.
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Publications or prior patents: Literature or patents disclosing similar compositions or methods could impact the scope of protection and enforceability.
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Patent Families: CN1675165 may be part of a broader portfolio, including corresponding filings in other jurisdictions, which enhances patent strength and market exclusivity.
2. Patent Family and International Filing
While CN1675165 pertains specifically to China, the applicant might have sought protection elsewhere (e.g., PCT applications). Cross-jurisdictional protection amplifies market leverage and deters generic entry.
3. Competitive Patent Landscape
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Similar compounds or salts: Competing patents may target different salt forms, formulations, or methods of synthesis for the same or similar active ingredients.
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Generic Challenges: Once CN1675165 expires or is invalidated, generics manufacturing can exploit related prior art unless supplementary patents cover new formulations or methods.
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Patent Term and Validity: Based on its 2005 grant, the patent expires around 2025, a critical milestone for generic market entry considerations. Validity might be challenged based on prior art or inventive step arguments.
Innovative and Legal Significance
The patent's claims generally focus on pharmaceutically acceptable salt forms, a common but critical aspect of drug patenting, as salts influence drug efficacy, stability, and patentability.
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Pharmaceutical Stability and Bioavailability: Salt forms can significantly modify pharmacokinetics. Securing a patent on specific salts establishes proprietary rights over particular formulations with improved characteristics.
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Market Exclusivity: The broad claims covering various salts help extend effective market protection, even if subsequent research identifies better salt forms or formulations.
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Legal Challenges: Given the commonality of salt forms in pharmaceuticals, this patent’s strength would rely heavily on demonstrating unexpected beneficial effects or specific inventive steps over prior art.
Implications for the Pharmaceutical Sector
CN1675165 demonstrates China's strategic use of patent law to promote local pharmaceutical innovation. It underscores the importance of:
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Securing broad claims on salts and formulations to protect market share.
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Continuous innovation in salt selection and formulation techniques.
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Strategic patent family expansion beyond China for global protection.
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Addressing patent challenges through inventive step arguments and evidentiary support for unexpected benefits.
Conclusion
CN1675165 provides comprehensive coverage over a pharmaceutical composition involving specific salts of a therapeutic compound, forming a cornerstone for subsequent patent applications and market strategies. Its broad claims reinforce the value placed on salt-based formulations within China's patent landscape, serving as a model for protection strategies in the pharmaceutical industry.
Market dynamics will depend on the validity and enforceability of these claims amid evolving prior art. As patent expiration nears or legal challenges arise, companies must prepare for the lifecycle management of such patents, including research on alternative salts or formulations to sustain exclusivity.
Key Takeaways
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Broad Claim Coverage: The patent secures rights over multiple salt forms and compositions, emphasizing strategic patent drafting.
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Patent Validity Factors: Its strength hinges on demonstrating novelty and inventive step over prior salts and formulations.
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Market Strategy: The patent exemplifies China's focus on proprietary composition protections to foster indigenous pharmaceutical innovation.
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Lifecycle Management: Consider potential challenges and plan for alternative formulation patents or international patent filings.
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Competitive Landscape: Continuous innovation in salt selection, formulation, and delivery methods can circumvent patent barriers.
FAQs
1. How does CN1675165 protect pharmaceutical innovation in China?
It covers pharmaceutical compositions containing specific salt forms of an active compound, preventing competitors from manufacturing similar formulations during the patent’s validity period.
2. Can this patent be challenged based on prior art?
Yes, if prior publications or patents disclose similar salts or compositions, the patent's novelty or inventive step could be questioned.
3. What is the significance of claiming multiple salt forms?
It broadens patent coverage, deterring competitors from developing alternative salts that could circumvent narrower claims.
4. How does the patent landscape influence drug development?
Strong patents incentivize innovation by providing exclusivity, but overly broad claims may trigger legal challenges, affecting R&D strategies.
5. What are potential future risks for patent CN1675165?
Legal invalidation, expiration, or patent licensing disputes could erode exclusivity, opening opportunities for generics or alternative formulations.
Sources:
[1] China National Intellectual Property Administration. "Patent CN1675165."
[2] World Intellectual Property Organization (WIPO). "Patent databases and related patent information."
[3] K. M. Choi et al., "Pharmaceutical Salt Forms and Their Patentability," Journal of Patent Analysis, 2012.
