Details for Patent: 8,877,245

Summary for Patent: 8,877,245

Title:	Modified release dosage forms of skeletal muscle relaxants
Abstract:	A unit dosage form, such as a capsule or the like, for delivering a skeletal muscle relaxant, such as cyclobenzaprine hydrochloride, into the body in an extended or sustained release fashion comprising one or more populations of drug-containing particles (beads, pellets, granules, etc.) is disclosed. At least one bead population exhibits a pre-designed sustained release profile. Such a drug delivery system is designed for once—daily oral administration to maintain an adequate plasma concentration—time profile, thereby providing relief of muscle spasm associated with painful musculoskeletal conditions over a 24 hour period.
Inventor(s):	Gopi Venkatesh, James M. Clevenger
Assignee:	Adare Pharma Solutions Inc
Application Number:	US13/570,670
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,877,245
Patent Claim Types: see list of patent claims	Use; Formulation; Dosage form;

Scope and Claim Strength of US Patent 8,877,245 (Cyclobenzaprine ER Beads) and Freedom-to-Operate Risk for Generic Muscle-Spasm Products

US 8,877,245 claims a tightly defined oral extended-release (ER) cyclobenzaprine hydrochloride (HCl) product: ER beads with (i) an active-containing core particle and (ii) a water-insoluble polymer membrane coat made from a specified polymer family, sized and release-profile constrained, with explicit in vivo exposure targets at 30 mg and 15 mg doses. The claim set is written primarily as method-of-use claims (administering the specified dosage form to relieve muscle spasms), but it is effectively a product-by-structure-and-performance claim because the dosage form is defined by composition, polymer selections, and quantitative dissolution and pharmacokinetic (PK) windows.

This patent’s enforceable scope is concentrated on: cyclobenzaprine HCl ER beads in capsule form; membrane-coated bead technology using water-insoluble polymer membranes from the listed classes; optional incorporation of water-soluble polymers and plasticizers; and performance targets including Cmax and AUC and a stepwise dissolution release profile in 0.1N HCl (USP Apparatus 2, 50 rpm). Any challenge to avoid infringement would need to alter at least one of the structural-definitional elements (core/coat polymer class, coat architecture and composition percentages, bead-coating fraction, capsule embodiment, seal coating) and/or the performance-defined elements (PK exposure targets and/or dissolution kinetics).

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What patents protect US 8,877,245’s cyclobenzaprine ER bead method-of-use in the US?

US 8,877,245 itself is the anchor. Based on the claim language provided, it covers administering a cyclobenzaprine HCl ER bead dosage form to relieve muscle spasms, with the dosage form defined by a polymer membrane that is both compositionally specified (polymer class list) and performance-specified (Cmax/AUC and dissolution release bands). That combination typically overlaps with other patents in a typical ER-bead portfolio (core technology, coating polymers, plasticizers, seal coatings, capsule embodiments, and PK/dissolution targets), but only 8,877,245 can be analyzed precisely here.

Core claim elements that drive infringement scope

Across independent claims 1 and 2 (30 mg) and independent claims 3 and 4 (15 mg), the shared required elements are:

1. Dosage form: “population of extended release beads” administered orally.
2. Bead structure:
   • Active-containing core particle comprising cyclobenzaprine hydrochloride.
   • Extended release coating comprising a water insoluble polymer membrane surrounding the core.
3. Polymer membrane definition: water-insoluble polymer membrane comprises a polymer selected from a specified set:
   • ethers/esters of cellulose
   • cellulose acetate
   • ethyl cellulose
   • polyvinyl acetate
   • neutral copolymers based on ethyl acrylate and methyl methacrylate
   • copolymers of acrylic and methacrylic acid ester with quaternary ammonium groups
   • “pH-insensitive ammonio methacrylic acid copolymers”
   • mixtures thereof
4. Dose strength: total cyclobenzaprine HCl in the dosage form is 30 mg (claims 1–2) or 15 mg (claims 3–4).
5. PK exposure constraints: independent claims embed numerical Cmax and AUC targets after a single oral administration.
6. Method of use: administering to a patient in need of relieving muscle spasms.

The result is an unusually narrow and enforceable claim pattern because both composition and in vivo exposure are required.

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What are the exact independent claim scopes of US 8,877,245 (30 mg vs 15 mg exposure windows)?

Independent claim 1 (30 mg; PK after single oral administration)

Required:

• ER beads with cyclobenzaprine HCl core
• water-insoluble polymer membrane using one of the listed polymer classes
• 30 mg cyclobenzaprine HCl total in dosage form
• single oral administration yields:
  • Cmax = 19.851 ± 5.8765 ng/mL
  • AUC0–168 = 736.60 ± 259.414 ng·hr/mL

Independent claim 2 (30 mg; AUC range differs by definition)

Same as claim 1 except:

• PK target is:
  • Cmax = 19.851 ± 5.8765 ng/mL
  • AUC0–∞ = 779.889 ± 277.6349 ng·hr/mL

Independent claim 3 (15 mg; lower exposure targets)

Required:

• ER beads with cyclobenzaprine HCl core
• water-insoluble polymer membrane using one of the listed polymer classes
• 15 mg cyclobenzaprine HCl total in dosage form
• single oral PK target:
  • Cmax = 8.315 ± 2.1635 ng/mL
  • AUC0–168 = 318.30 ± 114.657 ng·hr/mL

Independent claim 4 (15 mg; AUC0–∞ definition)

Same as claim 3 except:

• PK target is:
  • Cmax = 8.315 ± 2.1635 ng/mL
  • AUC0–∞ = 354.075 ± 119.8037 ng·hr/mL

Independent claim 5 (30 mg; normalized PK windows)

Same general dosage form requirements as claim 1 (including polymer membrane list), with:

• 30 mg cyclobenzaprine HCl
• PK performance expressed as ranges:
  • Cmax within 80% to 125% of ~20 ng/mL
  • AUC0–168 within 80% to 125% of ~740 ng·hr/mL

Practical scope implication: claim 5 gives broader numeric breathing room than the ± standard deviations in claims 1–2, so it is often the harder claim to design around if the alternative product matches the same core/coat polymer class and similar PK.

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What dissolution tests and release kinetics are required (USP Apparatus 2, 0.1N HCl) and how do they narrow infringement?

Claims 6–7 require specific dissolution release profiles under:

• USP Apparatus 2 (paddled @ 50 rpm)
• 900 mL of 0.1N HCl at 37°C

Claim 6 release profile

• after 2 hours: no more than 40% released
• after 4 hours: 40–65% released
• after 8 hours: 60–85% released

Claim 7 release profile

Same 2-hour, 4-hour, 8-hour ranges, plus:

• after 12 hours: 75–85% released

Practical scope implication: A generic attempting to move from this dissolution behavior (for example, shifting early release outside the 2-hour cap, or increasing late release beyond the 8–12 hour band) can aim to avoid the stepwise bands. But if the dissolution shift is paired with PK matching, a court may still find infringement depending on how the claim is construed (composition plus performance elements are required).

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What polymer membrane coatings are covered and which “escape” modifications are available?

The water-insoluble membrane is defined by a list of polymer classes. The infringement “escape” options narrow to:

1. Use a different polymer class not listed (strongest design-around in principle).
2. Use one listed class but change the membrane architecture such that it no longer qualifies as a “water insoluble polymer membrane surrounding said core” (harder to execute because most ER bead coatings will still be a membrane).
3. Keep the polymer in-list but alter formulation enough to miss the PK targets and/or dissolution bands (design-around by performance, but riskier).

Water-soluble polymer add-on is covered (dependent claims 9 and beyond)

Claim 9 adds optional coverage of a water soluble polymer selected from:

• methylcellulose
• hydroxypropylcellulose
• hydroxypropyl methylcellulose
• polyethylene polyvinylpyrrolidone
• mixtures thereof

Because claim 9 is dependent (“wherein ... further comprises”), a product without these polymers can still fall under independent claims so long as it meets the independents’ required polymer membrane definition and PK/dissolution constraints.

Plasticizer options and load percentages are covered (claims 10–11)

Claim 10 includes plasticizer classes such as triacetin, tributyl citrate, triethyl citrate, acetyl tri-n-butyl citrate, diethyl phthalate, dibutyl sebacate, PEG/PPG, castor oil, acetylated mono- and di-glycerides.

Claim 11 adds a numeric limitation:

• plasticizer amount about 10% to 25% by weight.

This is likely a key dependent constraint that only applies if the accused formulation includes that plasticizer range. A product outside that range can avoid claim 11 without avoiding independent claim coverage.

Coating amount and seal coating are covered (claims 13–14)

• Claim 13: “extended release coating comprises about 1% to about 15% by weight of said extended release heads” (note: claim uses “heads,” likely meaning beads).
• Claim 14: dosage form further comprises “a seal coating layer comprising hydroxypropyl methylcellulose or hydroxypropylcellulose.”

These are additional dependent claim hooks that can be used for infringement if an accused product includes those exact ranges/ingredients.

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How does claim architecture affect enforceability: method-of-use vs product definition?

Even though the claims are framed as methods (“administering a pharmaceutical dosage form”), the dosage form is defined in structural and performance terms:

• bead core active identity
• membrane polymer class list
• total cyclobenzaprine HCl amounts (15 mg/30 mg)
• Cmax/AUC numeric targets
• dissolution release bands

For freedom-to-operate planning, this means a generic’s risk is not limited to a literal capsule and excipient list. If it matches the defined bead coat polymer class and hits the same in vivo and in vitro performance, the method-of-use claim can be implicated through administration of that product.

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What generic entry risks exist for cyclobenzaprine ER products vs this patent?

Primary risk scenario

A generic that develops ER bead cyclobenzaprine HCl using a membrane made from one of the listed water-insoluble polymer classes, with similar dissolution kinetics and matching single-dose PK, risks reading directly on claims 1–5 (depending on dose strength and AUC definition).

Secondary risk scenario (dependent claims drive stronger “needle” matching)

If the generic includes:

• water-soluble polymers listed in claim 9
• plasticizer within the specific 10–25% range (claim 11)
• coating weight fraction within claim 13 range
• seal coating with hydroxypropyl methylcellulose or hydroxypropylcellulose (claim 14) then infringement arguments become more tailored because additional limitations are satisfied.

Design-around priorities (highest leverage)

1. Select a membrane polymer outside the listed class list.
2. If polymer stays in list, miss the PK windows and/or dissolution bands.
3. If PK/dissolution must match for regulatory purposes, change membrane polymer class and/or dissolution time profile in a way that fails at least one dependent numerical release band.

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What does the claim set imply about product form (capsule) and dosage regimen?

Claim 12 states: “pharmaceutical dosage form in the form of a capsule.”

This dependent limitation can matter for products that are tableted or produced in different unit forms. A capsule embodiment increases overlap with common ER cyclobenzaprine marketed formats.

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How broad is US 8,877,245’s claim scope: a quantified reading of numeric constraints

30 mg independent claims

• Cmax: 19.851 ± 5.8765 ng/mL
  This spans approximately 13.97 to 25.73 ng/mL by the ± definition.
• AUC0–168: 736.60 ± 259.414 ng·hr/mL
  This spans approximately 477.19 to 996.01 ng·hr/mL.

Claim 5 gives an alternative normalized approach (80% to 125% of ~20 and ~740 targets), which can be wider than the ± band depending on the underlying mean.

15 mg independent claims

• Cmax: 8.315 ± 2.1635 ng/mL
  Approximately 6.15 to 10.48 ng/mL.
• AUC0–168: 318.30 ± 114.657 ng·hr/mL
  Approximately 203.64 to 432.96 ng·hr/mL.

Dissolution gatekeeping

At each timepoint, infringement is sensitive to whether the released % falls within the bands:

• 2 hours: ≤40%
• 4 hours: 40–65%
• 8 hours: 60–85%
• 12 hours: 75–85% (only claim 7)

These numeric windows can be used as a “measurand checklist” when assessing whether a proposed generic profile aligns.

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Key Takeaways

• US 8,877,245 is a narrow ER-bead cyclobenzaprine HCl claim set defined by both composition and numeric performance.
• The independent method-of-use claims require: ER beads + cyclobenzaprine HCl core + water-insoluble membrane using listed polymer classes + 15 mg or 30 mg total dose + single-dose PK targets (Cmax and AUC) +, via dependent claims, stepwise dissolution release kinetics.
• The strongest infringement path is likely a generic that uses a listed water-insoluble polymer membrane and produces PK and dissolution behavior that matches the numeric windows.
• Design-around leverage is highest by changing the membrane polymer class (not just adjusting excipients), and secondarily by shifting dissolution and PK outside the specified limits.

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FAQs

1) Does US 8,877,245 require a specific bead size or number of beads?
The provided claims specify a “population of extended release beads” but do not state bead size distribution or number. The infringement-critical limitations are bead coat polymer class, coating architecture, total dose (15 mg/30 mg), and PK/dissolution performance.

2) Can a non-capsule formulation avoid dependent claim 12?
Yes, claim 12 is dependent and limits the dosage form to a capsule. However, the independent claims do not require capsule form, so avoiding claim 12 alone does not avoid claims 1–5 if the dosage form still meets their composition and PK/dissolution requirements.

3) Are the water-soluble polymer additives required for infringement?
No. The water-soluble polymers listed in claim 9 are in a dependent claim (“further comprises”). Their presence can strengthen an infringement theory but is not required for independent claim coverage if the water-insoluble membrane and PK/dissolution elements are met.

4) What is the most straightforward way to design around the PK limitations?
Achieve a formulation that falls outside the specified Cmax and AUC windows (or the normalized windows in claim 5), assuming the structural membrane polymer limitations are still met. This is riskier because PK matching may be targeted for regulatory bioequivalence.

5) Does the dissolution profile requirement apply to all independent claims?
No. The dissolution profile appears in dependent claims (6 and 7) that apply when the method is performed using a dosage form meeting those dissolution release bands in 0.1N HCl under USP Apparatus 2 conditions.

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References (APA)

1. US Patent 8,877,245.

Drugs Protected by US Patent 8,877,245

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 8,877,245

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
World Intellectual Property Organization (WIPO)	2005048996