Details for Patent: 7,981,877

Summary for Patent: 7,981,877

Title:	Stabilized steroid composition and method for its preparation
Abstract:	Stabilized, 17-substituted hydrocortisone containing compositions and methods of manufacture are disclosed. Isomerization of the hydrocortisone component of topical steroid compositions is markedly reduced by including an omega-6 acid component in the form of a free acid or as a compound such as an ester. Specifically disclosed are methods for preventing the isomerization of hydrocortisone 17-butyrate into hydrocortisone 21-butyrate through the use of safflower oil.
Inventor(s):	Pravin M. Patel
Assignee:	Precision Dermatology Inc
Application Number:	US11/432,742
Patent Claim Types: see list of patent claims	Use; Composition;

US Patent 7,981,877: Scope of Claims, Coverage Boundaries, and US Landscape

US Patent 7,981,877 is a method and composition patent focused on stabilizing hydrocortisone 17-butyrate (HCB) by inhibiting its isomerization to hydrocortisone 21-butyrate (H21B) using an omega-6 acid (or omega-6 ester) stabilizer, with specific stoichiometric thresholds that define enforceable claim scope. The claims are framed both as (i) a process for inhibiting isomerization and (ii) a process and product formulation for a “stabilized” hydrocortisone compound/composition.

---

What does the patent claim in plain technical terms?

The patent requires all of the following concept blocks:

1. Target substrate:

   • Hydrocortisone 17-butyrate (and in dependent claims “hydrocortisone compound comprising hydrocortisone 17-butyrate”).

2. Failure mode / transformation:

   • Isomerization of HCB to H21B (claim 1 explicitly).

3. Stabilizer identity:

   • A stabilizer comprising an omega-6 acid or an ester of an omega-6 acid.
   • Dependent claims narrow to linoleic acid (claim 2).
   • Additional narrowing includes omega-6 acid ester-containing triglycerides, including safflower oil (claims 3-4, 8, 12-13).

4. Quantity / threshold language that drives enforceability:

   • Omega-6 acid component is at least equimolar to the quantity of HCB (claims 5 and 7, and mirrored in composition claim 10).
   • In some claims, omega-6 is substantially greater than HCB (claim 6).
   • In composition claim 11, the omega-6 acid molar concentration is greater than the HCB molar concentration.
   • In claim 13, a weight-based limit is set: safflower oil at least 10x by weight relative to HCB.

These are not general “stabilize hydrocortisone esters” claims. They are anchored to: (a) HCB-to-H21B isomerization and (b) omega-6 acid chemistry plus (c) quantitative equivalence/excess.

---

What is the independent claim scope (Claims 1 and 7, plus composition Claim 9)?

Claim 1 (Method inhibiting isomerization)

Core elements:

• Method step: “disposing said hydrocortisone 17-butyrate in a composition”
• Composition must include: stabilizer comprising omega-6 acid or omega-6 acid ester
• Functional outcome: inhibition of isomerization of HCB to H21B (stated as the claim preamble and the method objective)
• No numeric ratio is required in Claim 1 itself (that appears in dependent claim 5 onward).

Practical coverage boundary: any formulation that places HCB into a composition containing an omega-6 acid/ester stabilizer can fall within the claim, as long as the method context is directed to inhibiting the isomerization to H21B.

Claim 7 (Method stabilizing HCB-containing compound)

Claim 7 expands beyond strict “inhibiting isomerization” framing into “stabilizing a hydrocortisone compound comprising hydrocortisone 17-butyrate.”

Key enforceable addition:

• The method requires the stabilizer addition to satisfy:
  • omega-6 acid component at least equimolar to HCB quantity.

Coverage boundary: Claim 7 is narrower than Claim 1 due to the stoichiometric requirement.

Claim 9 (Product composition)

A stabilized composition comprising:

• 17-hydrocortisone butyrate
• omega-6 acid or omega-6 acid ester stabilizer

No numeric ratio in the independent composition claim.

Coverage boundary: Claim 9 covers product formulations meeting identity of components; quantitative thresholds are pushed into dependent claims 10-13.

---

What do the dependent claims add (quantitative and material narrowing)?

Identity narrowing: specific omega-6 materials

• Claim 2: stabilizer comprises linoleic acid (a specific omega-6 acid).
• Claim 3: stabilizer includes a triglyceride that includes an ester of the omega-6 acid.
• Claim 4: the triglyceride comprises safflower oil.
• Claim 8: Claim 7 method, stabilizer comprises safflower oil.

Quantity thresholds: equimolar, “substantially greater,” and “greater than”

• Claim 5: add stabilizer such that omega-6 acid component is at least equimolar to HCB.
• Claim 6: omega-6 acid component is substantially greater than HCB (a stronger excess requirement).
• Claim 10: composition of Claim 9 where stabilizer amount yields omega-6 acid component at least equimolar to HCB.
• Claim 11: composition where the molar concentration of omega-6 acid component is greater than molar concentration of HCB.

Hard numeric ratio: weight-based safflower oil

• Claim 12: Claim 11 where stabilizer is safflower oil.
• Claim 13: weight percentage of safflower oil is at least ten times greater than weight percentage of HCB.

---

How is “omega-6 acid component” treated across claims?

Across Claims 5-7, 10-11, the language consistently points to a molecular component measure:

• “omega-6 acid component” implies that if the stabilizer is an ester or triglyceride, the claim focuses on the omega-6 acid moiety amount for stoichiometry.

This matters for formulation design because it suggests that simply adding a triglyceride with omega-6 content may not be enough unless the added amount is set so that the effective omega-6 acid component quantity meets:

• equimolar (claims 5, 7, 10)
• or greater than (claims 11)
• or substantially greater (claim 6).

Where claim 13 is used, a different metric is applied:

• weight % safflower oil vs weight % HCB (10x threshold).

---

What is the patent’s practical enforceable “design space”? (Mapping claims to formulation levers)

Formulations that are most likely to align tightly with claim language

• HCB is formulated with:
  • linoleic acid (Claim 2) or
  • an omega-6 ester-containing material like safflower oil (Claims 4, 8, 12-13)
• and, for higher-confidence coverage, formulation is set to:
  • omega-6 acid component >= equimolar (Claims 5, 7, 10)
  • or > molar concentration (Claim 11)
  • or (if using safflower oil) weight % safflower oil >= 10x weight % HCB (Claim 13)

Formulations that may still fall under broader independent claims

• A composition containing omega-6 acid/ester + HCB likely maps to:
  • Claim 9 (composition)
• and a process directed to inhibiting isomerization maps to:
  • Claim 1 (method inhibiting isomerization)

But the quantitative thresholds in dependent claims define the “strongest” subspaces, especially for freedom-to-operate and design-around analysis.

---

What parts are likely to be the infringement bottlenecks?

The likely friction points for any challenger or accused infringer are:

1. Isomerization context for Claim 1

   • Claim 1 is expressly about inhibiting the HCB to H21B isomerization.
   • A defendant will argue the accused formulation does not inhibit that pathway under relevant conditions.

2. Stoichiometric definition for Claims 5-7 and 10-11

   • “equimolar” and “molar concentration greater than” introduce measurement disputes.
   • For triglycerides, translating safflower oil into an “omega-6 acid component” amount drives calculation complexity.

3. Weight ratio for Claim 13

   • “weight percentage of safflower oil at least ten times greater than weight percentage of HCB” sets a clear numeric boundary.

---

Claims vs. patent landscape: what does US 7,981,877 likely sit among?

How this patent positions relative to common hydrocortisone ester stability approaches

Hydrocortisone ester stability patents in the US commonly cluster around:

• active ingredient selection/purity,
• packaging and moisture/oxygen control,
• antioxidants and radical scavengers,
• pH control and buffering,
• excipient system engineering,
• processing controls (granulation, milling, temperature/time).

US 7,981,877 differentiates itself by claiming a specific chemical stabilizer class (omega-6 acids/esters) with quantitative thresholds and an explicit isomerization target.

Implication for competitive landscape

Within a typical hydrocortisone formulation portfolio, this patent is most likely to matter when a competitor uses:

• omega-6-rich materials (e.g., safflower oil) or linoleic acid or similar,
• at sufficiently high levels to satisfy equimolar or greater molar thresholds,
• in formulations where HCB is present and where HCB-to-H21B isomerization is a known degradation route.

---

Freedom-to-operate map: risk categories by formulation choice

Category A: Low risk from identity

Avoid omega-6 acid/ester stabilizers entirely in HCB formulations. If a formulation has no omega-6 acid or omega-6 ester component, it is less likely to meet the stabilizer limitation in claims 1, 7, and 9.

Category B: Medium risk from identity but low risk from quantity

If omega-6 acid/esters are present but added below equimolar or “greater than” thresholds, infringement is more likely to align with broader independent claims (Claim 1 or 9) depending on isomerization inhibition evidence.

Category C: High risk

Formulations using omega-6 acids/esters, especially linoleic acid or safflower oil, and configured to meet:

• omega-6 acid component >= equimolar (Claims 5, 7, 10)
• or omega-6 acid component > molar concentration (Claim 11)
• or safflower oil weight ratio >= 10x (Claim 13)

This is the tightest match to dependent claims and supports a stronger infringement narrative.

---

What is the “scope of protection” across method and product claims?

US 7,981,877 covers three different infringement theories in practice:

1. Method of inhibiting isomerization (Claim 1)

   • Focus: process/disposing HCB in omega-6 stabilizer composition.

2. Method of stabilizing (Claim 7)

   • Focus: quantitative equimolar condition required.

3. Stabilized product (Claim 9 and dependents)

   • Focus: formulation composition with omega-6 stabilizer.
   • Dependents set quantitative thresholds that narrow the risk zone but also strengthen enforcement.

A competitor cannot rely solely on “we do not market a method.” Product formulation and manufacture can still expose them to composition claims.

---

Key Takeaways

• US 7,981,877 claims stabilization of hydrocortisone 17-butyrate by inhibiting its isomerization to hydrocortisone 21-butyrate using omega-6 acid or omega-6 acid ester stabilizers.
• Independent coverage exists for:
  • omega-6 stabilizer presence with HCB (Claim 1 method; Claim 9 composition).
• The strongest quantitative claim hooks are:
  • omega-6 acid component at least equimolar to HCB (Claims 5, 7, 10),
  • omega-6 acid component molar concentration greater than HCB (Claim 11),
  • and safflower oil weight % at least 10x HCB weight % (Claim 13).
• Linoleic acid and safflower oil/triglyceride omega-6 ester sources are the explicit narrow embodiments that concentrate enforceable scope.
• The competitive risk is highest when a hydrocortisone 17-butyrate product uses omega-6 rich excipients at levels sufficient to satisfy the stated stoichiometric thresholds.

---

FAQs

1) Does US 7,981,877 require safflower oil?
No. Safflower oil is a dependent narrowing embodiment (Claims 4, 8, 12-13). Independent claims cover any omega-6 acid or omega-6 acid ester stabilizer.

2) What ratio matters most for the strongest claim coverage?
Equimolar or greater omega-6 acid component vs hydrocortisone 17-butyrate (Claims 5, 7, 10, 11). For safflower oil specifically, Claim 13 adds a 10x weight % threshold.

3) Is the claimed degradation pathway specifically isomerization?
Yes. Claim 1 is expressly about inhibiting HCB-to-H21B isomerization.

4) Are there both method and product claims?
Yes. The patent includes method claims (Claims 1 and 7) and composition claims (Claim 9 and dependents).

5) What materials are explicitly called out?
Linoleic acid (Claim 2) and safflower oil (Claims 4, 8, 12-13), with triglyceride omega-6 ester sources captured in Claim 3.

---

References (APA)

[1] US Patent 7,981,877 (claims provided in prompt text).

Drugs Protected by US Patent 7,981,877

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