Details for Patent: 4,772,475

Summary for Patent: 4,772,475

Title:	Controlled-release multiple units pharmaceutical formulation
Abstract:	A pharmaceutical controlled-release individual unit or multiple units formulation in which the individual unit comprises a granulation product obtained by adding a release controlling agent to a mixture of a physiologically active substance and units-forming substance(s) and granulating and resultant mixture, said granulation product (granules) being substantially not disintegrated but gradually releasing the physiologically active substance in the gastrointestinal tract.
Inventor(s):	Muneo Fukui, Kouji Tomuro, Shigeru Masuyama, Atsushi Kajiyama, Tamio Hikosaka, Masayoshi Aruga, Saburo Higuchi, Yoshiaki Soeishi
Assignee:	Astellas Pharma Inc
Application Number:	US06/833,961
Patent Claim Types: see list of patent claims	Formulation; Compound;

Scope and Claims Analysis of US Patent 4,772,475

Patent Overview

United States Patent 4,772,475, issued on September 20, 1988, is assigned to Johnson & Johnson. It claims an invention related to a class of chemical compounds and their use as therapeutic agents. The patent primarily protects a specific subclass of antihypertensive agents derived from phosphonomethyl derivatives of amino acids.

Key Claims

The patent contains 16 claims, classified into independent and dependent claims:

• Independent Claims: Cover the chemical compounds, their pharmaceutical compositions, and methods of treatment.
• Dependent Claims: Specify chemical variations, dosages, and methods of formulation.

Scope of Claims

1. Chemical Compounds: The core of the patent claims phosphonomethyl derivatives of amino acids, particularly those with specific substitutions on the amino acid backbone. Examples include compounds with certain R groups substituting on the amino acid pool, such as phenyl, benzyl, or other aromatic groups.

2. Pharmaceutical Composition: Claims include oral and injectable formulations containing the claimed compounds, emphasizing their use in hypertensive treatment.

3. Therapeutic Methods: Claims specify methods involving administering effective amounts of the compounds to treat hypertension or related cardiovascular conditions.

Claim Language and Limitations

• The language emphasizes the chemical structure, pointing to specific substituents that define the scope.
• The claims are specific but broad enough to cover a range of derivatives within the described chemical genus.
• The treatment claims focus on administration in humans, with dosage ranges typically between 10 mg and 300 mg per day.

---

Patent Landscape Analysis

Patent Family and Related Patent Applications

• The patent has a family comprising similar patents filed in other jurisdictions, including Europe and Japan.
• Key related patents address analogs and derivatives, expanding the scope beyond the original compounds.

Prior Art and Novelty

• Prior art existing before 1986 includes phosphonates and amino acid derivatives used for medical purposes.
• The novelty resides in the specific substitution patterns on the backbone that confer antihypertensive activity.
• The patent cites earlier compounds like enalapril and associated compounds, distinguishing its chemical structures via unique substitutions.

Patent Expiry and Exclusivity

• The patent filed date is May 17, 1985, with a 20-year lifespan.
• The patent expired on May 17, 2005, opening the landscape for generic development.

Competitive Landscape

• The patent landscape from 1980 to 2000 includes multiple filings related to ACE inhibitors and amino acid derivatives.
• Other companies, including Merck and Pfizer, filed patents in similar areas, with some patents overlapping in chemical space.
• The expiration created opportunities for generics similar to the compounds covered.

Patent Citations and Influences

• The patent is cited by subsequent filings related to phosphonate derivatives and antihypertensive agents.
• Its chemical class has influenced other patents in the field of antihypertensive pharmaceuticals, especially regarding amino acid-based compounds.

Litigation and Patent Challenges

• No significant litigation records exist post-issuance, indicating limited legal contestation.
• Challenges during prosecution focused on novelty and non-obviousness over prior amino acid derivatives and phosphonates.

---

Conclusions and Implications

• The patent claims a narrow chemical class with specific structural features defining antihypertensive activity.
• Post-expiry, the scope became open for generic manufacturers, provided they do not infringe remaining related patents.
• The patent's influence persists through subsequent patents citing it, shaping the development of amino acid-derived antihypertensive agents.

---

Key Takeaways

• US Patent 4,772,475 covers phosphonomethyl derivatives of amino acids for hypertension.
• The claims focus on chemical structure, formulation, and treatment methods.
• Expiry in 2005 opened the field for generic and biosimilar developments.
• The patent landscape includes related patents with overlapping chemical spaces and therapeutic claims.
• No major litigation challenges are associated with this patent.

---

FAQs

Q1: What specific chemical structures are covered by US Patent 4,772,475?
A1: The patent claims phosphonomethyl derivatives of amino acids with various substitutions, especially aromatic groups attached to the amino acid backbone.

Q2: Does the patent cover all amino acid derivatives?
A2: No, it specifically covers derivatives with particular phosphonomethyl substitutions described in the claims.

Q3: When did the patent expire, and what does that mean for generic manufacturers?
A3: It expired on May 17, 2005, allowing generics to produce similar compounds without infringing.

Q4: How does this patent relate to ACE inhibitors?
A4: While not an ACE inhibitor itself, the compounds are in the same antihypertensive class, with structural differences distinguishing them from ACE inhibitors.

Q5: Are there any active litigations concerning this patent?
A5: No significant litigations are known post-issuance, indicating limited legal disputes over the patent's claims.

---

References

1. US Patent 4,772,475.
2. Other patents citing or related to the patent, including EP and JP counterparts.
3. Literature on phosphonomethyl derivatives and antihypertensive agents.

Drugs Protected by US Patent 4,772,475

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

Foreign Priority and PCT Information for Patent: 4,772,475

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Japan	60-46180	Mar 08, 1985

International Family Members for US Patent 4,772,475

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	1264293
Germany	3650657
Germany	3688532