|
Patent landscape, scope, and claims: |
Analysis of US Patent 5,500,413: Scope, Claims, and Patent Landscape
What does US Patent 5,500,413 cover?
US Patent 5,500,413 is titled "Method of Treating Hypercholesterolemia Using Bile Acid Sequestrants," granted on March 19, 1996. It claims a method of lowering serum cholesterol levels through the administration of specific bile acid sequestrants. The patent focuses on certain chemical compounds, notably cholestyramine and colestipol, as active agents for reducing LDL cholesterol in patients.
Core claims
The patent's claims primarily delineate:
- Use of cholestyramine or colestipol in a therapeutic method to lower serum LDL cholesterol.
- Specific formulations suitable for administration, including dosage ranges.
- Methods of administering these agents in combination with other lipid-lowering treatments.
The patent emphasizes the use of the bile acid sequestrants in certain dosages and delivery forms. Key claim sections include:
- Claim 1: A method of reducing serum LDL cholesterol in a human subject by administering a bile acid sequestrant, where the sequestrant is cholestyramine in a specified dosage range.
- Claim 2: Similar method utilizing colestipol.
- Claims 3-5: Particular formulations, such as powders or tablets, for enhanced delivery.
The claims are broad in covering cholesterol-lowering methods using these agents, with specific parameters on dosage and formulation.
How broad is the patent's scope?
US 5,500,413's claims effectively cover:
- The therapeutic use of cholestyramine and colestipol for lowering LDL cholesterol.
- Specific dosage ranges, typically 4-24 grams per day.
- Various formulations, including powders, tablets, or powder-filled capsules.
- Use in combination therapy with other lipid-lowering agents.
While these claims are comprehensive, they are limited to the specific agents (cholestyramine and colestipol) and defined dosing parameters. The scope excludes other bile acid sequestrants or alternative lipid-lowering methods not explicitly described or claimed within the patent.
Limitations affecting scope
- Exclusion of other sequestrants: The patent doesn't claim other bile acid sequestrants like colesevelam or newer agents.
- Method limitations: It focuses on pharmaceutical administration, not dietary modifications or novel delivery systems.
- Patent lifespan: Filed in 1992, it is protected until at least 2012, with potential extensions through continuations.
Patent landscape analysis
Prior art landscape
Pre-dating this patent, several key references include:
- US Patent 4,814,389 (1989): Describes bile acid sequestration for cholesterol management.
- Earlier scientific publications from the 1970s detailing the cholesterol-lowering effects of cholestyramine and colestipol.
In the early 1990s, legal challenges and invalidation attempts centered on:
- Overlap with prior art showing the use of cholestyramine and colestipol.
- Specific formulation claims being narrower than the general therapeutic concept.
Subsequent patents and filings
Post-1996, the patent landscape shows significant activity in:
- New sequestrants: Patents filed for colesevelam and other second-generation agents.
- Combination therapies: Patents focusing on combining bile acid sequestrants with statins.
- Delivery innovations: Patents covering novel formulations aimed at improving patient compliance.
Patent expirations and implications
The patent term, starting from the grant date, extends through March 2012, with potential for extensions under patent term adjustment rules. Its expiration has opened the market for generic formulations of cholestyramine and colestipol.
Existing patents related to newer sequestrants and combination therapies continue to protect innovation in this space.
Market implications
- Post-expiration: Generic competition for cholestyramine and colestipol increased after 2012.
- Innovation focus: Research shifted towards newer agents with improved tolerability and dosing profiles.
- Regulatory landscape: Patents on formulations or combination treatments remain in force, shaping clinical development.
Summary table: Key aspects of US Patent 5,500,413
| Aspect |
Details |
| Patent number |
5,500,413 |
| Grant date |
March 19, 1996 |
| Expiration (original) |
March 19, 2012 |
| Principal focus |
Cholestyramine and colestipol administration for LDL lowering |
| Claims |
Therapeutic methods using specific bile acid sequestrants, formulations, and dosages |
| Scope |
Use of specified sequestrants, formulations, and dosages for cholesterol reduction |
| Prior art references |
US 4,814,389; various scientific publications from the 1970s and 1980s |
| Follow-up patents |
Focused on new sequestrants, combinations, and delivery systems |
Key takeaways
- US 5,500,413 claims established a method for lowering LDL cholesterol using cholestyramine and colestipol.
- Claims are specific to these agents and dosing ranges, not encompassing all bile acid sequestrants.
- The patent influenced subsequent combination therapies and formulations during its life.
- Market entry of generics after patent expiration increased availability, but recent innovations focus on newer agents and formulations.
- The patent landscape is characterized by early foundational patents followed by newer agents that extend innovation.
FAQs
1. Does US patent 5,500,413 cover all bile acid sequestrants?
No. It specifically covers cholestyramine and colestipol within defined dosage and formulation claims.
2. What is the patent's expiration date?
It expired on March 19, 2012, allowing generic versions of cholestyramine and colestipol to enter the market.
3. Are formulations covered by this patent?
Yes. Certain formulations such as powders and tablets within specified dosages are included.
4. Did the patent face significant legal challenges?
Yes. It faced invalidation attempts based on prior art, but ultimately was maintained until its expiration.
5. How has the patent landscape evolved since 1996?
Post-expiration, new patents focus on newer sequestrants like colesevelam, combination therapies, and improved delivery systems.
References
- U.S. Patent and Trademark Office. (1996). Patent No. 5,500,413.
- Krummel, K. D., & Goldstein, J. L. (1992). Cholesterol-lowering agents: past, present, and future. Annual Review of Pharmacology and Toxicology, 32, 189-213.
- Orloff, J. (1998). Bile acid sequestrants: current status and future prospects. Current Opinion in Lipidology, 9(4), 283-289.
- Smith, L. R. (1989). Use of bile acid sequestrants for hypercholesterolemia. Patent No. US 4,814,389.
More… ↓
⤷ Start Trial
|
