Details for Patent: 8,758,813

Summary for Patent: 8,758,813

Title:	Abuse-deterrent drug formulations
Abstract:	An abuse-deterrent pharmaceutical composition has been developed to reduce the likelihood of improper administration of drugs, especially drugs such as opioids. In one embodiment, the drug is modified to increase its lipophilicity by forming a salt between the drug and one or more fatty acids wherein the concentration of the one or more fatty acids is one to 15 times the molar amount of the active agent. The abuse-deterrent composition prevents the immediate release of a substantial portion of drug, even if the physical integrity of the formulation is compromised and the resulting material is placed in water, snorted, or swallowed. However, when administered as directed, the drug is slowly released from the composition as the composition is broken down or dissolved gradually within the GI tract by a combination of enzymatic degradation, surfactant action of bile acids, and mechanical erosion.
Inventor(s):	Jane Hirsh, Alison Fleming, Roman Rariy, Alexander M. Klibanov
Assignee:	Collegium Pharmaceutical Inc
Application Number:	US13/870,690
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,758,813
Patent Claim Types: see list of patent claims	Use; Composition;

United States Patent 8,758,813 (Oxycodone Fatty-Acid Salt Solid Microparticles): Scope, Claim Construction Levers, and US Patent Landscape

Executive summary: US Drug Patent 8,758,813 claims a pain-management method using a solid microparticle formulation in which oxycodone is present as a fatty-acid salt and the microparticle contains (i) one or more fatty acids present at a defined molar excess over the oxycodone salt and (ii) wax/wax-like carrier materials. The claim scope is driven by four quantitative/structural anchors: fatty-acid identity range (C5–C30 monovalent or C8–C40 divalent), fatty acid molar ratio (6.9–15x), carrier amount (0.25–8x by weight), and wax carrier species (e.g., carnauba/beeswax/microcrystalline). The tightest commercially relevant coverage is typically for oxycodone myristate (myristic acid salt) with beeswax/car­nauba wax and specific loading ratios. The broader strategic risk for generic entry is strongest where competitors replicate salt form + excess free fatty acid + wax microparticle rather than simply switching to another carrier or another salt chemistry.

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What is US Patent 8,758,813 claiming for oxycodone microparticles for pain?

Core claim theme (independent claim 1): A method of managing pain by administering a therapeutic composition that is a solid microparticle. The microparticles comprise:

1. Active agent: a fatty acid salt of oxycodone
2. One or more fatty acids: present at 6.9 to 15 times the molar amount of the active agent
3. Carrier materials: waxes or wax-like substances

Independent claim 1 scope hinges on:

• Salt form: “fatty acid salt of oxycodone” (not oxycodone base or oxycodone hydrochloride per se)
• Presence of free/extra fatty acid(s) as a separate component in the microparticle matrix, not merely the acid used to form the salt
• Quantified fatty acid molar excess: 6.9–15x (a measurable formulation parameter)
• Microparticle format: “solid microparticles” (excludes bulk solutions and many non-particulate dosage concepts)

Dependent claims that narrow or crystallize scope

• Claim 2: fatty acid molar concentration 6.9–10x
• Claim 3/4: fatty acid carbon-number windows:
  • C5–C30 monovalent fatty acids OR
  • C8–C40 divalent fatty acids OR mixtures
• Claim 5/6: expanded list of specific fatty acids (from pentanoic through triacontanoic and including linoleic and oleic)
• Claim 7/8: myristic acid specifically
• Claims 9–12: carrier amount by weight:
  • 0.25–8x carrier:active by weight (claims 9–10)
  • 2–6x carrier:active by weight (claims 11–12)
• Claims 13–16: specific wax classes: carnauba wax, beeswax, microcrystalline wax
• Claims 15–16: beeswax + carnauba wax mixture
• Claims 17–18: specific “product-like” combination:
  • oxycodone myristate,
  • myristic acid,
  • beeswax + carnauba wax
• Claims 19–20: active agent preparation: contacting molar excess fatty acid with oxycodone free base

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Which claim elements are most important for infringement under US Patent 8,758,813?

Infringement risk is highest where all four anchors are met simultaneously:

1) Is the active agent truly a “fatty acid salt of oxycodone”?

• If a competitor uses oxycodone HCl/oxycodone sulfate or another non-fatty-acid counterion, it generally falls outside the salt definition.
• If a competitor uses a fatty-acid salt but does not include the specified molar excess of fatty acid in the microparticle composition, they may avoid the quantification requirements.

2) Are “one or more fatty acids” present at 6.9–15x molar excess?

This is a formulation-quantification limiter. A competitor can design around by:

• Using the fatty acid to form the salt but not retaining free/extra fatty acid at the claimed molar ratio, or
• Using a different molar ratio outside 6.9–15x (including tightening below 6.9x or using >15x, depending on how the competitor measures the ratio).

3) Are the excipients “waxes or wax-like substances” and in the claimed amount?

Carrier amount is expressly constrained:

• 0.25–8x by weight (claims 9–10)
• 2–6x by weight (claims 11–12)

If the competitor uses a non-wax carrier or moves outside the weight window, scope narrows.

4) Are the carriers the claimed wax species?

The broad carrier language covers waxes/wax-like substances, but certain dependent claims lock to:

• Carnauba wax
• Beeswax
• Microcrystalline wax
• Mixtures of beeswax + carnauba wax

A competitor that uses other waxes (or wax-like polymers) may still argue against the dependent coverage, while independent claim 1 may still capture if their carrier is within the “waxes or wax-like substances” universe.

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What formulations are covered: oxycodone fatty-acid salts, myristic acid, and wax microparticles?

Patent claim “coverage matrix” by formulation specificity

Formulation attribute	Independent coverage (Claim 1)	Tight coverage via dependents
Active agent	Fatty-acid salt of oxycodone	Myristic acid salt (Claims 7, 8, 17, 18)
Fatty acid identity	1+ fatty acids (via Claims 3–6 carbon ranges and enumerations)	Myristic acid (Claims 7–8)
Fatty acid molar excess	6.9–15x vs active agent	6.9–10x (Claim 2)
Carrier type	Waxes / wax-like substances	Carnauba/beeswax/microcrystalline (Claims 13–14); beeswax+carnauba (Claims 15–16)
Carrier:active weight ratio	0.25–8x (Claims 9–10)	2–6x (Claims 11–12)
Microparticle format	Solid microparticles	Not further limited beyond particulates

How “myristic acid salt” and beeswax/car­nauba create the highest risk

The narrowest dependent claims function like a “compositions list”:

• Claim 17–18: oxycodone + myristic acid salt + myristic acid + beeswax/car­nauba wax.
  If a competing product replicates that exact salt-excess-carrier combination within the quantitative constraints, it is closest to claim architecture.

Salt-prep language: does Claims 19–20 add infringement leverage?

Claims 19–20 are method-of-preparation limitations for the active agent:

• “prepared by contacting a molar excess of one of the one or more fatty acids with the free base”

In practice, in litigation this can cut both ways:

• It can strengthen a theory if the accused manufacturer’s process evidence shows the claimed preparation approach.
• It may not always be required for product-by-process relevance depending on claim interpretation and how the active agent’s salt state is established.

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How do the fatty-acid molar ratios and carbon-number limits affect design-around strategies?

Fatty-acid molar ratio (6.9–15x) as the primary quantitative fence

A generic or reformulation effort must control:

• Total fatty acid count in the microparticle
• The distinction between fatty acid used to form the salt vs remaining as additional free fatty acid
• Analytical measurement methodology (e.g., titration, chromatographic quantification of fatty acids vs salts)

Design-around candidates include:

• Changing excess such that fatty acids are <6.9x or >15x relative to the salt.
• Switching to a fatty acid outside the carbon-number windows in Claims 3–6, such as C4 monovalent or C7 divalent, if it is feasible to form a stable oxycodone salt and still meet other formulation requirements.
• Using mixtures where at least one component is outside the enumerated list may still fit the “one or more” language if the mixture still contains included fatty acids; this becomes an empirical/analytical question.

Carbon-number / saturation profile as secondary constraints

Claims 3–6 provide a defined universe:

• C5–C30 monovalent fatty acids
• C8–C40 divalent fatty acids
• Included exemplars cover saturated and unsaturated (e.g., linoleic acid, oleic acid)

This is a broad palette. The key is whether the competitor’s fatty acid identity is inside that legal definition.

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What wax carrier types and loading ranges are protected by US 8,758,813?

Carrier amount

• 0.25–8x by weight (Claims 9–10)
• 2–6x by weight (Claims 11–12)

This makes the formulation “recipe” defensible at the excipient loading level. A competitor using a different wax level may reduce the risk of meeting the claimed composition.

Carrier species

• Dependent claims identify:
  • carnauba wax
  • beeswax
  • microcrystalline wax
  • and mixtures, including beeswax + carnauba wax

Even if the independent claim’s “waxes or wax-like substances” language is broader, these dependents set litigation anchor points if the accused product’s excipient list matches.

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What is the US Orange Book status of oxycodone microparticle formulations resembling US 8,758,813?

No Orange Book status can be reliably stated from the claim text alone, and an exact listing requires the drug’s FDA application number, reference product name, and the Orange Book entry mapped to the patent (US 8,758,813). This analysis cannot produce a complete Orange Book mapping without those data points.

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What other US patents likely cover oxycodone salt-based extended-release pain formulations with fatty acids and wax microparticles?

Claim 1 is formulation-method focused, not solely salt chemistry. The landscape around US 8,758,813 typically splits into three overlapping patent buckets that often appear together in this chemistry space:

1. Salt formation patents for oxycodone fatty-acid salts (myristate and other fatty acids)
2. Particle engineering patents for solid microparticles or dispersion systems using wax-like carriers
3. Dose design and composition patents controlling:
   • carrier:wax ratios,
   • fatty acid molar excess,
   • and specific wax blends

Strategic implication: even if a competitor avoids the exact molar excess ratio, other patents may still apply if they target the same dosage form concept (wax matrix microparticles with opioid fatty-acid salts), or if they cover manufacturing methods or particle size distributions tied to extended-release pain management.

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How strong is the patent estate for US 8,758,813 against generic competition?

Strength drivers based on claim structure:

• The invention is defined by multiple conjunctive constraints (salt form + fatty acid molar excess + wax microparticles + carrier loading range).
• The claim set includes both broad ranges (fatty acids C5–C30 monovalent; carrier type broad) and tight embodiments (myristic acid; beeswax/car­nauba; defined ratios).

Typical generic entry defenses:

• Use a different opioid counterion (avoid fatty-acid salt)
• Use the same fatty-acid salt but adjust fatty acid molar excess to fall outside 6.9–15x
• Replace wax carriers with non-wax sustained-release systems (lipid nanoparticles, polymer matrices)
• Use different wax species and outside the specific dependent combinations

Typical infringement theories:

• If the accused product uses oxycodone fatty-acid salt and retains free fatty acid in the same molar excess range, the remaining carriers and ratios become the primary battleground.

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What Paragraph IV, ANDA, or biosimilar risks exist for oxycodone fatty-acid salt microparticles?

This patent concerns oxycodone, a small-molecule drug. It is therefore implicated in ANDA-type generic challenges rather than biosimilar pathways. However, without the patent’s FDA reference product mapping and litigation docket identifiers, no precise Paragraph IV events, defendants, or settlement terms can be stated here.

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How does US 8,758,813 compare with other opioid controlled-release IP strategies (salt + lipid/wax vs polymer matrices)?

US 8,758,813 is positioned in the broader opioid sustained-release landscape as a lipid/wax microparticle strategy with a salt chemistry lever (fatty-acid salts). Compared with polymer-based controlled-release systems, the legal novelty often centers on:

• Salt counterion selection (fatty acids vs traditional pharmaceutically accepted inorganic salts),
• in-matrix excess fatty acid quantification,
• wax carrier matrix selection and loading.

Where polymer systems rely on diffusion and erosion through polymer networks, this patent claims rely on a composition-defined wax microparticle matrix coupled to oxycodone salt/fatty acid stoichiometry.

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Commercial exposure: what products could be at risk if they use oxycodone myristate plus beeswax/car­nauba wax microparticles?

Risk is highest for products that replicate:

• oxycodone myristate (fatty-acid salt)
• myristic acid present at 6.9–15x molar relative to the oxycodone salt
• waxes including beeswax and carnauba wax
• within the claimed carrier weight ratios

Products that only partially overlap (for example, oxycodone myristate but with no excess myristic acid, or wax microparticles but with a different counterion) reduce the probability of meeting all limitations.

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Timeline: when would patent rights end for US 8,758,813?

No reliable expiration date, PTA/adjustment status, or term-extension figures are derivable from the claim text alone. Accurate “when does exclusivity end” analysis requires docketed patent metadata and calculation inputs (filing date, issue date, PTA, and any term adjustments).

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Key Takeaways

• US 8,758,813 claims a pain management method using solid microparticles containing oxycodone as a fatty-acid salt, plus one or more fatty acids in a defined molar excess (6.9–15x) and waxes/wax-like carriers.
• The highest-infringement concentration is the dependent-claim pathway: oxycodone myristate + myristic acid with beeswax/car­nauba wax, within the stated molar and weight windows.
• Generic design-around efforts would most plausibly pivot on (i) counterion change, (ii) removing or lowering free fatty acid to <6.9x, and/or (iii) switching carrier system away from waxes or outside the claimed weight ratios.
• A complete landscape of Orange Book listings, Paragraph IV challenges, competitors, and expiration timelines is not possible from the claim text provided.

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FAQs

1. What design-around changes most directly avoid US 8,758,813?
   Switching oxycodone away from a fatty-acid salt, or adjusting in-microparticle fatty-acid molar excess to fall outside 6.9–15x, or changing the carrier away from wax systems or outside 0.25–8x by weight.

2. Does US 8,758,813 cover oxycodone HCl or oxycodone sulfate formulations?
   Not based on the claim text, which requires “fatty acid salt of oxycodone.”

3. How does the “myristic acid” dependent claim narrow infringement risk?
   It adds an explicit fatty-acid identity requirement and, in further dependents, an explicit wax blend and composition combination.

4. Are manufacturing-process steps needed to infringe?
   The composition and administration method are the claim focus; process language in Claims 19–20 can matter more where the active agent’s preparation is evidenced or where a product-by-process argument is pursued.

5. Would changing wax type avoid infringement?
   It can avoid dependent claims that specify carnauba/beeswax/microcrystalline, but independent claim coverage can still apply if the substitute is a “wax or wax-like substance” and the quantitative constraints are met.

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References

1. US Patent 8,758,813 (claims provided in prompt).

Drugs Protected by US Patent 8,758,813

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

International Family Members for US Patent 8,758,813

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2003247876
Canada	2491572
Canada	2569958
Canada	2916869