|
Patent landscape, scope, and claims: |
US Patent 5,776,885 (Dry Sustained-Release Peptide Salt with PLA/PLGA) — Scope, Claim Map, and Landscape
US 5,776,885 claims a dry, sustained-release pharmaceutical composition that embeds a therapeutically active peptide as a water-insoluble pamoate salt within biodegradable lactic acid and/or polylactide polymers (PLA/PLGA). The composition is engineered to release peptide continuously for at least one week and then maintain peptide activity for at least one month in an aqueous physiological environment. Dependent claims narrow to specific peptide pamoates, particle size, rod/implant formats, initial burst limits, and gamma sterilization.
What does the independent claim cover (Claim 1)?
Claim 1 defines the core invention. It is a product-by-function + formulation + performance profile claim:
Core limitations (must all be met)
- Dry pharmaceutical composition designed for sustained release.
- Active ingredient format: therapeutically active peptide as its pamoate salt (explicitly “water-insoluble peptide salt” and “pamoate salt” is central throughout the specification logic implied by the claim set).
- Matrix polymers:
- polylactide polymer, or
- polymer of lactic and glycolic acid (PLGA), or
- mixture of the above.
- Release/performance profile in aqueous physiological environment:
- releases peptide continuously for at least one week
- then maintains activity for at least one month
- No extra sterility, particle size, or implant geometry is required in Claim 1 (those are pushed into dependent claims).
Performance language creates a functional boundary
The phrase “releases the peptide in a continuous manner for a period of at least one week followed by maintenance of activity of the peptide for at least one month” functions as an operational requirement. In practice, this typically correlates to polymer degradation kinetics, peptide salt water-insolubility, and formulation morphology.
How broad is Claim 1 versus typical peptide depot patents?
Claim 1 is broad on peptide choice but narrow on salt form and matrix chemistry. It is not limited to one peptide in the independent claim; it requires:
- pamoate salt (water-insoluble salt),
- PLA/PLGA-type matrix (polylactide and/or lactic-glycolic polymer),
- dry sustained-release performance (week+ month activity).
This is broader than depot patents that lock to:
- a single peptide (e.g., LHRH only),
- a specific polymer grade or specific molecular weight range,
- a specific dosage form (e.g., microspheres only),
but narrower than generic “biodegradable polymer sustained release peptide” claims because it hard-codes pamoate and PLA/PLGA family.
What do dependent claims add (Claim 2 to Claim 12)?
Peptide scope narrowing
- Claim 2: pamoate salt of LHRH or a synthetically prepared analog.
- Claim 3: pamoate salts of a defined list of peptides/peptide classes and derivatives:
- oxytocin, vasopressin, ACTH, calcitonin, EGF, prolactin, inhibin, interferon, somatostatin,
- insulin, glucagon, atrial natriuretic factor, endorphin,
- a renin inhibitor,
- growth hormone releasing hormone (GHRH),
- peptide T,
- and synthetic analogues thereof.
- Claim 4: pamoate salt of D-Trp6-LHRH.
- Claim 5: pamoate salt of D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2.
Claim 3 is the most expansive peptide-dependent claim in the set because it lists many peptide targets and still ties them back to the Claim 1 structure and performance requirements.
Particle size limitation
- Claim 6: composition in particles sized 1 to 500 μm.
Dosage form geometry and sterilization
- Claim 7: composition is a solid rod, sterilized by gamma radiation.
- Claim 9: composition is in rod form for parenteral implant.
Burst control limitation
- Claim 8: no more than 30% of total peptide amount released initially in the first 24 hours.
Additional sterility + carrier structure
- Claim 10: like Claim 1 but additionally:
- gamma-sterilized
- and suspended in a pharmaceutically acceptable carrier.
Internal dispersion
- Claim 11: peptide salt dispersed within solid polymer particles.
Specific “embodiment lock-in” example chemistry
- Claim 12: peptide salt is D-Trp6-LHRH pamoate and polymer is D,L-lactide and glycolide polymer.
Claim-by-claim “design-around” sensitivity
The following chart translates the claims into enforceable switches. A “design-around” typically changes one or more switches so the product no longer meets the full set of limitations.
| Claim element |
Where it appears |
Why it matters for scope |
| Dry composition |
Claim 1 |
Limits to formulations consistent with dry depot construction; wet implants and in-situ hydration may fall outside this claim language. |
| Pamoate salt (water-insoluble peptide salt) |
Claim 1 and throughout |
Strongest constraint. Switching to other salts (e.g., acetate, citrate, sulfate) is the most direct route to exit. |
| PLA/PLGA matrix (polylactide / lactic-glycolic polymer) |
Claim 1 |
Switching to non-lactide/non-glycolide polymers (e.g., poly(ε-caprolactone), PEG-based depots, ethylene-vinyl acetate + salt adsorption, etc.) is a direct route to exit. |
| Release timeline (≥1 week continuous release; activity maintained ≥1 month) |
Claim 1 |
Even if salt and polymer are used, meeting the performance profile is required. |
| Gamma sterilization |
Claims 7 and 10 |
If a competitor avoids gamma sterilization or uses a different sterilization method, those dependent claims narrow materially. |
| Rod implant format |
Claims 7 and 9 |
Competitors in microspheres or injectable in situ gels can avoid these. |
| Particle size 1-500 μm |
Claim 6 |
Tightens morphology; out-of-range particle sizes avoid the dependent claim. |
| Burst limit (≤30% in 24 hours) |
Claim 8 |
Forces formulation to control initial release kinetics. |
| Specific peptides and analogs |
Claims 2-5 |
Locks enforceability around listed targets for those dependent claims. |
What is the likely claim “center of gravity”?
Most enforceable core
- Claim 1 plus Claim 3 (peptide list) are the likely core of commercial leverage because they cover many clinically relevant peptides while staying anchored to the same salt + polymer platform.
Most targeted commercial embodiments
- Rod implants (Claims 7 and 9) track common administration formats for peptide depots.
- Gamma sterilized products (Claims 7 and 10) matter because sterilization approach can be a bottleneck in manufacturing and may be visible in regulated product dossiers.
- Burst limitation (Claim 8) is a performance metric that competitors often need to match, especially where early release correlates to safety or tolerability.
Product concept matrix: what would practice infringe?
Infringement risk is highest when a product has:
- Peptide pamoate as the dispersed drug form,
- PLA/PLGA matrix,
- dry sustained-release structure,
- meets the week+ month release/activity profile in aqueous physiology,
- optionally uses rod implants, gamma sterilization, and/or meets ≤30% burst.
Any switch away from pamoate salt or PLA/PLGA is the most direct way to move outside Claim 1.
How does this patent define the “patent landscape” around peptide depots?
US 5,776,885 sits at the intersection of three patent clusters:
- Peptide depot engineering via biodegradable polymers
- PLA/PLGA is a common biodegradation toolkit.
- Use of poorly soluble salt forms to slow release
- pamoate (an anionic counterion strategy) is a recognizable lever to reduce aqueous solubility.
- Performance-anchored depot claims
- explicit release durations (≥1 week release, ≥1 month activity) and burst metrics (≤30% in 24 hours) are enforceability enhancers.
Within the broader depot landscape, many patents overlap on PLA/PLGA matrices but differ on:
- the drug salt form,
- the drug entity (one peptide vs many),
- the morphology (rod vs microsphere vs implant),
- sterilization and manufacturing controls.
Where are the “forks” in the landscape most likely to occur?
Fork A: Salt form (pamoate vs other counterions)
- If pamoate is replaced, Claim 1’s salt-form requirement is likely not met.
- Many competitors can still achieve sustained release using other salt systems, polymer blends, or encapsulation strategies.
Fork B: Polymer family (PLA/PLGA vs other biodegradables)
- If a non-lactide/non-glycolide polymer is used as the principal matrix, Claim 1’s matrix limitation is likely not met.
Fork C: Dosage form and sterilization
- Rod implants and gamma sterilization appear in dependent claims, so competitors using alternative geometries or sterilization modalities may still face Claim 1 risk but reduce dependent-claim exposure.
Fork D: Kinetic performance
- Even with pamoate + PLA/PLGA, the release/activity window (week+ month) and burst control (≤30% in 24 hours) create measurable performance boundaries.
Practical infringement risk map (platform view)
| Competitor formulation attribute |
If it matches 5,776,885 |
Net effect on claim coverage |
| Peptide is in pamoate form |
Matches Claim 1 |
Increases risk substantially. |
| Matrix is PLA/PLGA or polylactide |
Matches Claim 1 |
Increases risk substantially. |
| Product is dry depot |
Matches Claim 1 |
Supports “composition” match. |
| Release is tuned for ≥1 week continuous + ≥1 month activity |
Matches Claim 1 |
Makes Claim 1 performance boundary central. |
| Rod implant + gamma sterilization |
Matches Claims 7/9/10 |
Adds dependent-claim exposure. |
| Particle size within 1-500 μm |
Matches Claim 6 |
Adds dependent-claim exposure. |
| Burst in first 24h is kept ≤30% |
Matches Claim 8 |
Adds dependent-claim exposure. |
Key takeaways
- Claim 1 is the main platform claim: dry depot, peptide pamoate salt, and PLA/PLGA matrix, with continuous release for at least one week and activity maintenance for at least one month in aqueous physiology.
- Dependent claims target enforcement leverage around specific peptides (LHRH analogs and a broad peptide list), depot morphologies (rod implant), sterilization (gamma), particle size (1-500 μm), and burst control (≤30% in 24 hours).
- The two highest-value design-around switches are (1) salt form and (2) polymer family. Geometry and sterilization are secondary, mostly affecting dependent claims.
- The performance metrics are enforceability anchors: release duration and burst constraint create measurable boundaries that can distinguish products even when salt and polymer match.
FAQs
-
Does Claim 1 require any specific peptide?
No. Claim 1 requires the peptide be present as a pamoate salt and that the depot meet the week+ month performance profile, but it does not limit the peptide identity.
-
Which element is most likely to determine whether a product falls within the claim scope?
The combination of pamoate salt and PLA/PLGA matrix, plus the release/activity timeline in aqueous physiological conditions.
-
Can a competitor avoid Claims 7 and 10 without changing the core formulation?
Yes, by changing gamma sterilization and/or avoiding rod/implant formats, but Claim 1 exposure may remain if the core pamoate + PLA/PLGA + performance profile is unchanged.
-
What does Claim 8 add from a formulation standpoint?
A burst limitation: no more than 30% of total peptide released in the first 24 hours.
-
How do Claims 4 and 5 differ from Claims 2 and 3?
Claims 4 and 5 lock to specific D-amino-acid LHRH variants and a defined peptide sequence in pamoate salt form, while Claims 2 and 3 cover broader classes (LHRH and a multi-peptide list).
References
[1] U.S. Patent 5,776,885.
More… ↓
⤷ Start Trial
|
