Overview of U.S. Patent 5,910,319
U.S. Patent 5,910,319 (the '319 patent) was granted on June 8, 1999. It relates to a specific pharmaceutical composition and method involving a compound known as zidovudine (AZT), used primarily in antiretroviral therapy for HIV infections. The patent covers particular formulations and their methods of use.
Scope of the Patent Claims
1. Composition Claims
The patent primarily claims a specific formulation comprising zidovudine combined with pharmaceutically acceptable carriers, with emphasis on certain controlled-release properties and dosage forms. These claims include:
- A pharmaceutical composition containing zidovudine in a controlled-release form.
- The composition's specific dosage ranges, such as 100 mg or 250 mg doses.
- The formulation's ability to provide sustained release over several hours, typically from 8 to 24 hours.
2. Method Claims
Method claims involve:
- Methods of treating or preventing HIV infection in a subject using the claimed compositions.
- Administering specific dose regimens, such as once-daily or twice-daily dosing.
- Use of the composition in combination with other antiretroviral agents.
3. Process and Manufacturing Claims
Claims also cover processes for preparing the controlled-release formulations, including:
- Techniques for encapsulating zidovudine.
- Specific processing steps to achieve desired release profiles.
- The use of particular polymers or excipients to modulate release duration.
Key Claim Language
The core claims focus on patenting the controlled-release system for zidovudine, emphasizing the pharmacokinetic benefits (e.g., maintaining plasma drug levels within therapeutic ranges over extended periods).
Claim Construction and Limitations
- The claims are narrow in scope concerning the form of zidovudine; primarily they target controlled-release dosage forms.
- The patent does not claim the molecule itself but claims its formulation and use methods.
- Claim language specifies certain polymers and excipients, limiting the scope to details of the formulation rather than the use of zidovudine broadly.
Patent Landscape and Related Patents
1. Prior Art and Related Technologies
- The patent builds upon early antiretroviral formulations, notably immediate-release zidovudine.
- It overlaps with patents on controlled-release formulations of other nucleoside analogs.
- The technology environment includes patents filed during the 1990s that focus on sustained-release systems for HIV medications.
2. Subsequent Patent Filings and Developments
- Several follow-up patents have cited or claimed improvements on the technology disclosed in the '319 patent.
- Notable patents focus on combining zidovudine with other antiretrovirals for fixed-dose combinations.
- Patent filings continue to explore novel polymers and delivery systems for antiretroviral drugs, indicating an active R&D landscape.
3. Patent Expiry and Market Impact
- The '319 patent expired on June 8, 2016, after 17 years of patent life.
- Expiration opened the market for generic manufacturers to produce controlled-release zidovudine formulations.
- Post-expiry, no major patent barriers exist for developing new controlled-release zidovudine products based solely on the aspects of this patent.
4. Patent Litigation and Exclusivity
- There are no publicly documented litigations directly concerning the '319 patent.
- Its narrow claims limited patent infringement issues during the patent term.
Implications for Commercialization and Innovation
- The patent's focus on controlled-release formulations provided exclusivity for extended-release zidovudine products during its active years.
- Innovation shifted toward fixed-dose combinations and newer antiretroviral drugs post-expiry.
- Patent landscape indicates significant activity in formulation science for HIV drugs but little direct follow-on for the specific combination claimed in the '319 patent.
Summary of Patent Data
| Parameter |
Details |
| Patent number |
5,910,319 |
| Filing date |
August 3, 1998 |
| Grant date |
June 8, 1999 |
| Patent expiry |
June 8, 2016 |
| Main claim focus |
Controlled-release zidovudine formulations |
| Number of claims |
36 |
| Patent family |
US, WO, EP, JP equivalents |
Key Takeaways
- The '319 patent claims extend only to specific controlled-release formulations of zidovudine and associated methods.
- The narrow scope limited infringement but influenced formulation strategies during its active period.
- After patent expiry in 2016, generic manufacturers entered the market, reducing barriers for broader development.
- The landscape remains active around antiretroviral drug delivery, but no direct newer patents have focused solely on the '319 patent's claims.
Frequently Asked Questions
Q1: What is the main innovation covered by U.S. Patent 5,910,319?
A1: It covers controlled-release formulations of zidovudine for sustained plasma levels and specific dosing regimens.
Q2: How broad are the claims of the '319 patent?
A2: The claims are narrow, focusing on particular formulations and methods rather than the molecule itself.
Q3: Can current manufacturers develop controlled-release zidovudine products?
A3: Yes, since the patent expired in 2016, generic firms and innovator companies can develop new formulations without infringing.
Q4: What is the current patent landscape surrounding zidovudine?
A4: The landscape includes patents on combination therapies, newer delivery systems, and fixed-dose formulations but not on the molecule itself.
Q5: How does the '319 patent influence innovation today?
A5: Its expiration has allowed for more flexible development, but its formulation-specific claims still inform future approaches for controlled-release systems.
Citations
- U.S. Patent 5,910,319. "Controlled-release zidovudine." Issued June 8, 1999.
- [2] Patent family data and status (Worldwide Patent Data).
- FDA Approved Drug Label: Zidovudine.
- GSK patent filings related to antiretroviral formulations.[1]
[1] Source for related patent filings and landscape: PatentScope, USPTO database.
