United States Patent 5,795,864: Omega conopeptide formulations stabilized against methionine oxidation
What does US 5,795,864 claim in scope?
US 5,795,864 is directed to a stable omega conopeptide formulation where stability is achieved by including an antioxidant composition that prevents methionine oxidation. The claims also lock in preferred buffer chemistry and define specific “omega-conopeptide” sequences by SEQ ID.
Claim set (as provided)
- Stable omega conopeptide formulation comprising:
- an omega conopeptide; and
- an antioxidant composition capable of preventing methionine oxidation.
- The formulation of claim 1 where the antioxidant composition includes a carboxylic acid buffer.
- The formulation of claim 2 where the carboxylic acid buffer is lactate buffer.
- The formulation of claim 1 where the antioxidant is methionine.
- The formulation of claim 1 where the antioxidant composition includes:
- lactate buffer and
- methionine.
- The formulation of claim 1 where the omega conopeptide is SNX-273, sequence SEQ ID NO: 35.
- The formulation of claim 1 where the omega conopeptide is SNX-279, sequence SEQ ID NO: 36.
Immediate scope boundaries
The core claim scope is formulation-level rather than new peptide discovery. The essential elements that define infringement risk are:
- “Omega conopeptide formulation” (core active class)
- an antioxidant composition that prevents methionine oxidation (stability mechanism)
- optional but claim-defining formulation features:
- carboxylic acid buffer (claim 2)
- lactate buffer (claim 3)
- methionine antioxidant (claim 4)
- a specific combination: lactate buffer + methionine (claim 5)
- at least in claims 6 and 7: inclusion of specific omega conopeptides:
- SNX-273 (SEQ ID 35)
- SNX-279 (SEQ ID 36)
This architecture means the patent can read on products where methionine oxidation is suppressed by an antioxidant system, even if the antioxidant is not methionine itself (depending on whether claim 4/5 are asserted). If lactate buffering is used, the scope tightens to claims 2, 3, and 5.
How broad is the antioxidant and stabilization limitation?
The stabilization limitation is functional: “capable of preventing methionine oxidation.” That wording is typically broad because it does not require a specific stoichiometry, concentration range, or manufacturing method in the claim text you provided. The practical breadth depends on what the specification and prosecution history did with that functional language, which is not included in the provided data.
Breadth mapping by claim dependency
| Claim |
Additional required limitation |
Scope implication |
| 1 |
Omega conopeptide + antioxidant composition that prevents methionine oxidation |
Baseline formulation protection; any antioxidant system meeting the functional stability requirement may fall within scope. |
| 2 |
Antioxidant includes a carboxylic acid buffer |
Narrows to antioxidant systems that include a carboxylic acid buffer component. |
| 3 |
Carboxylic acid buffer is lactate buffer |
Further narrows to lactate-containing compositions. |
| 4 |
Antioxidant is methionine |
Narrows to methionine as the antioxidant. |
| 5 |
Antioxidant composition includes lactate buffer and methionine |
Narrows to a specific two-component antioxidant/buffer pair. |
| 6 |
Omega conopeptide is SNX-273 (SEQ ID 35) |
Narrows peptide identity. |
| 7 |
Omega conopeptide is SNX-279 (SEQ ID 36) |
Narrows peptide identity. |
Two key scope levers
- Functional stabilization: “capable of preventing methionine oxidation” can cover multiple antioxidant approaches if they actually prevent oxidation in the claimed formulation context.
- Component identity: claims 4 and 5 explicitly require methionine, with claim 5 also requiring lactate buffer.
How do the SEQ ID-defined omega conopeptides constrain enforceability?
Claims 6 and 7 tie protection to SNX-273 (SEQ ID NO: 35) and SNX-279 (SEQ ID NO: 36). The biological sequence is the gatekeeper for these dependent claims.
What matters for landscape and freedom-to-operate
- If an entrant uses an omega conopeptide that is not SNX-273/279, then claims 6/7 are not directly implicated.
- If an entrant uses SNX-273 or SNX-279, then claims 1-5 still matter because dependent claims may be asserted across formulation variants.
- Even if the entrant avoids lactate or avoids methionine, claim 1 may still be asserted if their antioxidant system prevents methionine oxidation.
Practical risk posture
- Highest risk: formulations using lactate buffer + methionine with SNX-273/SNX-279.
- Moderate risk: formulations with methionine but without lactate, or with lactate but without methionine, depending on whether the functional antioxidant performance supports “capable of preventing.”
- More distant risk: formulations that use different antioxidant mechanisms that still prevent methionine oxidation could still test the functional claim 1.
What does this mean for formulation developers targeting omega conopeptides?
US 5,795,864 sets an explicit formulation objective: stabilize against methionine oxidation using an antioxidant system, with preferred components that include carboxylic acid buffers (lactate) and methionine.
Formulation design space that intersects claim language
Below are the intersections with the claim elements, using only what appears in the claims provided:
-
If methionine oxidation is addressed by an antioxidant system
- Claim 1 is the likely starting point.
-
If the antioxidant system includes carboxylic acid buffering
- Claim 2 becomes relevant.
-
If buffering is lactate
- Claim 3 is directly aligned.
-
If methionine itself is used
-
If both lactate buffering and methionine are used
How does the patent position in the US conopeptide formulation landscape?
The provided claim text indicates a formulation stabilization approach, not a method-of-treatment claim. In the omega conopeptide space, this typically interacts with a cluster of formulation and stability patents that address:
- oxidation control for methionine-containing peptides,
- pH and buffer selection,
- excipient systems for solubility and aggregation control,
- container closure and storage-induced degradation.
Even without additional documents, US 5,795,864 is structurally the kind of patent that tends to be asserted for drug product stability formulations where methionine oxidation is observed and mitigated.
Landscape role of US 5,795,864 (claim-based inference)
| Landscape category |
Where US 5,795,864 sits |
| Drug product stabilization |
Core focus is oxidation stabilization via antioxidant composition |
| Buffer selection |
Explicitly claims carboxylic acid buffer, specifically lactate |
| Antioxidant selection |
Explicitly claims methionine antioxidant |
| Product identity |
Dependent claims narrow to SNX-273/279 sequences |
What would an invalidity or non-infringement strategy look like (claim-element based)?
This section frames the logic for legal and technical strategies using the claim elements you provided.
Non-infringement focus points
-
Antioxidant performance
- For claim 1: the accused formulation must not be “capable of preventing methionine oxidation.”
- If the formulation does not prevent methionine oxidation under claimed conditions, claim 1 can be avoided.
-
Component absence
- For claim 2/3: remove carboxylic acid buffer components, or specifically avoid lactate buffer.
- For claim 4/5: avoid using methionine as antioxidant, or avoid the lactate + methionine combination.
-
Peptide identity
- Avoid SNX-273 (SEQ ID 35) and SNX-279 (SEQ ID 36) if trying to avoid claims 6/7.
Invalidation focus points
Without prior art citations and the specification, the most that can be stated from your claim language is that invalidity arguments would target:
- lack of novelty in “omega conopeptide + antioxidant preventing methionine oxidation,” and
- lack of inventive step for selecting lactate buffer and/or methionine as stabilization components,
- or obviousness from known peptide stabilization practices.
Those strategies usually require comparing claim elements to earlier formulation disclosures and demonstrating that the claimed combination was known or obvious.
What is the practical freedom-to-operate risk profile?
Based on the claim architecture alone:
Highest exposure combinations (claims 1-7)
- Omega conopeptide formulation containing:
- an antioxidant system that prevents methionine oxidation (claim 1),
- plus lactate buffer as the carboxylic acid buffer (claims 2-3),
- plus methionine as antioxidant (claims 4-5),
- plus using SNX-273 (claim 6) or SNX-279 (claim 7).
Medium exposure combinations
- Lactate buffer included but antioxidant is not methionine (claim 2/3 still relevant; claim 4/5 not met).
- Methionine included but lactate buffer omitted (claim 4 relevant; claim 2/3 and 5 depend on lactate inclusion).
- Antioxidant prevents methionine oxidation but does not include the claimed buffer/antioxidant identity (could still hit claim 1).
Lower exposure combinations
- Formulations that do not prevent methionine oxidation (avoid claim 1).
- Formulations that avoid all lactate and methionine-specific limitations (avoid claims 2-5) but still must address claim 1.
- Products using non-SNX-273/279 omega conopeptides (avoid claims 6/7).
Key Takeaways
- US 5,795,864 protects drug product formulations of omega conopeptides with an antioxidant system that prevents methionine oxidation.
- The claim scope is defined by a functional stability limitation in claim 1, then narrowed by explicit component requirements in claims 2-5.
- Dependent claims 6 and 7 constrain the protected omega conopeptide identity to SNX-273 (SEQ ID 35) and SNX-279 (SEQ ID 36).
- The highest enforcement risk sits at formulations combining lactate buffer + methionine to prevent methionine oxidation in SNX-273/SNX-279 products.
FAQs
-
Does claim 1 require methionine as the antioxidant?
No. Claim 1 only requires an antioxidant composition capable of preventing methionine oxidation; methionine as antioxidant is specified in claims 4 and 5.
-
Is lactate buffer mandatory to fall under the patent?
No. Lactate buffer is required only in claims 3 and 5. Claim 1 and claim 4 do not require lactate.
-
Do claims 6 and 7 protect the peptides themselves?
Based on the provided claim text, claims 6 and 7 cover formulations where the omega conopeptide identity is SNX-273 (SEQ ID 35) or SNX-279 (SEQ ID 36), not peptide manufacture claims.
-
What is the key infringement trigger across the claim set?
The central trigger is a formulation having an antioxidant composition that is capable of preventing methionine oxidation (claim 1), with additional narrowing when lactate buffer and/or methionine are included.
-
How can a formulation developer reduce risk relative to this patent?
Risk reduction follows claim-element avoidance: eliminate carboxylic acid buffer/lactate, avoid methionine as the antioxidant, and/or avoid SNX-273 and SNX-279 as the omega conopeptide identity, while also ensuring methionine oxidation is not prevented in the sense required by claim 1.
References
- US Patent 5,795,864. Claims 1-7 (as provided in prompt).
