US Patent 9,827,241: Scope, Claim Boundaries, and Competitive Landscape
US Patent 9,827,241 is centered on an injectable, depot-forming buprenorphine formulation that transforms in situ into an implant after contact with bodily fluid. The claims tie together three technical elements: (1) buprenorphine (free base or pharmaceutically acceptable salt), (2) a lactide-co-glycolide copolymer (PLGA-type), and (3) N-methyl-2-pyrrolidone (NMP), with multiple dependent provisions setting composition windows, polymer grade details, and administration schedules.
Based on the claim text provided, the patent’s enforceable scope is best understood as a composition-of-matter portfolio with method-of-treatment claims that are tethered to the specific formulation compositions.
What is the core invention and how is it framed in the claims?
Claim architecture
The patent uses three main claim “families”:
-
Core in situ depot composition
- Injectable composition with:
- 8 wt% to 30 wt% buprenorphine (free base or pharmaceutically acceptable salt)
- 15 wt% to 70 wt% poly(DL-lactide-co-glycolide) copolymer
- 10 wt% to 70 wt% NMP
- Plus the functional limitation: transformed in situ into an implant by contact with bodily fluid
- Representative claims: 1, 5, 10, 14, 28, 29
-
More specific sub-variants
- Narrow windows (specific polymer ratios, specific molecular weights, free base requirement, carboxy terminal group, and buprenorphine:polymer ratio).
- Representative claims: 3, 4, 6, 7, 9, 16-23, 30-33, 37-40
-
Downstream therapeutic methods
- Treating opioid dependency/addiction (and also pain in humans) by administering the claimed composition(s).
- Representative claims: 11-15, 34-35, 53-58
Functional trigger that matters
The “in situ implant” limitation appears in multiple compositions:
- Claim 1 includes the in situ implant transformation.
- Claims 5 and 14 repeat this “implant formation by bodily fluid contact” limitation.
- Claims 28 and 29 add a different formulation window (notably different polymer and NMP ranges) while still requiring in situ implant transformation (claim 29).
This means the claim set is not merely a buprenorphine-in-solvent or buprenorphine-in-polymer composition. It is constrained to compositions that self-assemble into a depot/implant in vivo under bodily fluid contact.
What are the absolute composition limits that define claim coverage?
A. “Core” composition-of-matter (PLGA + NMP + buprenorphine)
Independent composition claim 1 (and closely related claims) defines a three-component ratio space:
| Component |
Lower bound |
Upper bound |
Form/constraint |
| Buprenorphine |
8 wt% |
30 wt% |
free base or pharmaceutically acceptable salt |
| Poly(DL-lactide-co-glycolide) copolymer |
15 wt% |
70 wt% |
polymer grade not fixed in claim 1 |
| N-methyl-2-pyrrolidone (NMP) |
10 wt% |
70 wt% |
none stated beyond wt% |
| Functional |
N/A |
N/A |
“transformed in situ into an implant by contact with bodily fluid” |
Replicated in:
- Claim 5 (composition mirrors claim 1, with “consisting of” framing)
- Claim 10 (composition without the in situ condition text)
- Claim 14 (composition “consisting of” with in situ condition)
- Claims 11-13, 15 (methods anchored to claim 1 or claim 5 or claim 10)
Key boundary implication: literal infringement requires each component to fall in the specified wt% ranges. Outside those ranges, the literal claim is likely not met.
B. Alternative formulation window with expanded NMP (Claim 28)
Independent composition claim 28 defines a separate space:
| Component |
Lower bound |
Upper bound |
Form/constraint |
| Buprenorphine free base |
8 wt% |
about 22 wt% |
free base only |
| PLGA (poly(DL-lactide-co-glycolide)) |
15 wt% |
about 50 wt% |
average MW about 5,000 to about 40,000 Daltons |
| NMP |
30 wt% |
70 wt% |
none stated beyond wt% |
| Functional |
N/A |
N/A |
claim 29 adds in situ implant transformation |
Additional constraints in claim 28 family:
- Claim 30: copolymer is 50/50
- Claim 31: copolymer MW about 5,000 to 40,000
- Claim 32: polymer has a carboxy terminal group
- Claim 33: buprenorphine:copolymer weight ratio between 0.01:1 and 2:1
Key boundary implication: this claim set is narrower on buprenorphine form (free base only) and has an explicitly higher NMP requirement (30 wt% to 70 wt%).
C. “Injectable pharmaceutical composition” variant (Claims 41–52)
Independent composition claim 41 changes the polymer naming from “poly(DL-lactide-co-glycolide)” to poly(lactide-co-glycolide) copolymer and adjusts polymer wt% range:
| Component |
Lower bound |
Upper bound |
Form/constraint |
| Buprenorphine |
8 wt% |
about 30 wt% |
free base or salt |
| Poly(lactide-co-glycolide) copolymer |
5 wt% |
about 70 wt% |
polymer ratio not fixed in claim 41 |
| NMP |
10 wt% |
about 70 wt% |
none stated beyond wt% |
| Functional |
N/A |
N/A |
no explicit “in situ implant” text in claim 41 |
Dependent constraints:
- Claim 50: 24 hour burst release < 10%
- Claim 51: polymer MW about 5,000 to 20,000
- Claims 46-48: many PLGA lactide/glycolide ratios (50/50 through 95/5, plus specific preferred ratios)
- Claim 49: “consisting of (i), (ii), and (iii)”
- Claims 52: buprenorphine is free base
This family therefore creates a second enforceable anchor on release profile (via claim 50) and polymer specs (via molecular weight and ratio selections).
How do the “consisting of” claims narrow scope versus “comprising” claims?
A major claim-interpretation lever is whether the claim is “comprising” or “consisting of.”
- “Comprising” (e.g., claim 1) leaves room for additional excipients, because it is inclusive.
- “Consisting of” (e.g., claim 5, 14, and 49) is restrictive: the composition is limited to the enumerated components (and typically excludes additional ingredients).
Examples:
- Claim 5 and Claim 14: “injectable composition consisting of” buprenorphine + PLGA + NMP, plus in situ implant limitation.
- Claim 49: “composition of claim 41, consisting of (i), (ii), and (iii)”
- So claim 49 likely excludes additional components beyond buprenorphine, the copolymer, and NMP.
Business consequence: competitors trying to design around by adding stabilizers, surfactants, salts, or other process aids may still fall under “comprising” claims but could potentially avoid “consisting of” claims if the claims are construed strictly to exclude those additives.
What claim dependencies control technical specificity (polymer MW, ratios, end groups, and drug form)?
1) Buprenorphine form
- Free base support: claim 16 (under claim 1), claim 17 (under claim 5), claim 52 (under claim 41), and claim 28 (free base only).
- Salt support: claim 1 and claim 5 allow “free base or pharmaceutically acceptable salt.”
This matters for design-around:
- A formulation that uses only buprenorphine salt can still map onto the “free base or salt” claims.
- A formulation that uses only buprenorphine free base is compatible with all “free base” dependent claims too, but not vice versa.
2) Polymer composition ratio selections
3) Polymer molecular weight windows
- For poly(DL-lactide-co-glycolide) in early family:
- Claim 4: MW 5,000 to 40,000 Daltons
- In claim 28:
- Claim 31: MW 5,000 to 40,000
- In claim 41 family:
- Claim 51: MW 5,000 to 20,000 (tightens the window)
This means a competitor using higher MW PLGA (above 20,000) may avoid claim 41 dependent claim 51 but can still fall within independent or other dependent claim coverage unless those are tied to 51.
4) Carboxy terminal group
- Claim 32: polymer has a carboxy terminal group.
If a competitor uses PLGA grades without carboxy-terminated characteristics, claim 32 is harder to hit (but claim 1/41 remain available depending on whether their polymers meet only MW and wt% requirements rather than terminal group.
5) Buprenorphine loading in mg
- Claim 2 / 8 / 18 / 22 / 36: buprenorphine 3 mg to about 300 mg.
- Claim 56: therapeutically effective buprenorphine dose 3 mg to about 300 mg.
- Claim 57: therapeutically effective buprenorphine dose 9 mg to about 900 mg (method claim).
The mg dosing language is likely intended to capture specific unit doses and dosing regimens rather than just concentration in the injectable mixture.
6) Buprenorphine:copolymer weight ratio
- Claim 33: 0.01:1 to 2:1 (buprenorphine to copolymer).
This is a second “design-around” lever distinct from wt% ranges because it constrains the relationship between drug and polymer even if a company changes total solids.
What is the therapeutic scope: opioid dependency, opioid addiction, and pain?
1) Opioid dependency
Method claims target opioid dependency via administration of claim-linked compositions:
- Claim 11: method for opioid dependency using composition of claim 1
- Claim 12: method using composition of claim 5
- Claim 13: method using composition of claim 10
- Claim 15: method using composition of claim 14
- Claim 24-27: dosing frequency: subcutaneous once per month for methods tied to claims 11-15
Also:
- Claim 34: method using composition of claim 28
- Claim 35: subcutaneous once per month for claim 34
2) Opioid addiction (human methods)
- Claim 53: method for treating opioid addiction using claim 41 composition
- Claim 54: once per month by subcutaneous injection
- Claim 55: once every three months by subcutaneous injection
- Claim 56: therapeutically effective dose 3 mg to about 300 mg
- Claim 57: therapeutically effective dose 9 mg to about 900 mg
3) Pain
- Claim 58: method for treating pain in a human using claim 41 composition.
Business implication: the patent is not limited to opioid dependency pharmacology; it extends to pain (claim 58) tied to the claim 41 pharmaceutical composition. That expands the “use” risk for formulations in adjacent indications where the same depot composition is used.
How strong is the scope around release kinetics (burst release)?
Only the claim 41 family explicitly recites a quantitative release property:
- Claim 50: “composition of claim 41 having a 24 hour burst release of less than 10%.”
This is significant for infringement strategy and design-around:
- Competitors can attempt to match wt% and MW but could still avoid dependent claim 50 if their profile fails the “<10% burst in 24 hours” requirement.
- If the independent coverage does not require burst release, then claim 50 mainly tightens an additional layer on top of claim 41.
What design-around space is implied by the claim boundaries?
Based purely on the claim terms provided, the most obvious “escape routes” from literal coverage are:
-
Modify polymer grade or terminal group
- Avoid claim 32 if polymer lacks carboxy terminal groups.
- Avoid claim 51 if MW is above 20,000 in the claim 41 family dependent context.
-
Use a different solvent system than NMP
- All major composition claims listed here require NMP. A different high-boiling solvent could avoid these composition claims.
-
Shift formulation out of wt% windows
- Buprenorphine and PLGA and NMP have explicit ranges in each family.
-
Use a different buprenorphine form with respect to free base-only limitations
- Claim 28 is free base only; claim 1/5/41 allow either.
-
Avoid in situ implant transformation
- Claims 1/5/14/29 have the explicit in situ implant transformation limitation.
- If a product forms a pre-made implant or different solidification mechanism not triggered by bodily fluid contact, it may not satisfy that functional claim feature.
-
Avoid “consisting of” enumerations by adding other components
- Claims 5, 14, and 49 are “consisting of” constrained.
Patent landscape and competitive mapping (US context)
A complete landscape requires bibliographic data (assignee, filing history, prosecution status, cited art, family members, and maintenance status). That information is not present in the prompt, and producing it without sources would be non-actionable.
What can be done from the claim text alone is a landscape taxonomy of how competitors can be categorized relative to the patent’s technical hypothesis:
Cluster 1: NMP-based buprenorphine + PLGA injectable depots that form implants in situ
- High risk of covering:
- Formulations that use NMP with buprenorphine and PLGA and claim or achieve in situ depot/implant formation after injection.
- Coverage likely overlaps:
- “Implant by bodily fluid contact” compositions (claims 1/5/14/29).
- wt% windows for buprenorphine, PLGA, and NMP.
Cluster 2: NMP-based buprenorphine + PLGA injectable depots with different solidification mechanism
- Risk depends on whether product can meet “transformed in situ into an implant by contact with bodily fluid.”
- If solidification occurs via other mechanisms (temperature change, pre-formed implant, photoactivation), “in situ implant by bodily fluid contact” may not be met.
Cluster 3: PLGA depots in other solvents
- If NMP is replaced, the composition claims here likely do not map literally.
Cluster 4: Same solvent + polymer but different release kinetics
- If the product matches wt% and polymer parameters but has higher 24-hour burst:
- It may still avoid dependent claim 50 but could still be covered by broader independent claims depending on construction.
Cluster 5: Same ingredients but non-“consisting of” compositions
- Adding extra excipients could avoid “consisting of” limitations (claims 5/14/49), while not necessarily avoiding “comprising” claims (claim 1).
Key claim-to-landscape “coverage matrix”
| Product design feature |
Claim sets most exposed |
| Uses NMP + PLGA + buprenorphine |
Core composition claims: 1, 5, 10, 14, 28, 29, 41 |
| Has in situ implant formation triggered by bodily fluid |
1, 5, 14, 29 |
| Uses buprenorphine free base only |
16/17 and claim 28 (and claim 52) |
| Uses PLGA with carboxy terminal group |
32 |
| Uses PLGA MW above 20,000 in the claim 41 space |
Avoids claim 51 dependent, not necessarily independent claim 41 |
| Targets very low 24-hour burst (<10%) |
Aligns with claim 50 |
| Uses added ingredients beyond the three enumerated components |
Potentially reduces exposure to “consisting of” claims: 5, 14, 49 |
Key Takeaways
- US 9,827,241 is fundamentally about a buprenorphine + PLGA + NMP injectable that can transform into an implant in situ (claims 1, 5, 14, 29).
- The strongest literal coverage is anchored on three-component wt% windows and, for selected claims, on functional depot formation by bodily fluid contact.
- The claim set splits into (a) in situ implant compositions (early and claim 28/29) and (b) a separate claim 41 family that emphasizes pharmaceutical composition constraints, including 24-hour burst release <10% (claim 50) and polymer specs (MW and ratio).
- “consisting of” dependent claims (notably 5, 14, 49) create a design-around pathway by avoiding exactly the listed components only.
- Method claims extend the use risk to opioid dependency/addiction and also pain, with explicit subcutaneous monthly and subcutaneous every-three-months schedules tied to the claim 41 composition.
FAQs
1) Which single claim most broadly captures the composition concept?
Claim 1 (injectable composition with 8-30 wt% buprenorphine, 15-70 wt% poly(DL-lactide-co-glycolide), 10-70 wt% NMP, and in situ implant formation by bodily fluid contact).
2) Where does the patent explicitly limit burst release?
Claim 50 limits 24-hour burst release to less than 10% for the claim 41-based composition.
3) What is the main design-around for the in situ implant limitation?
Use an injectable depot system that does not form an implant through bodily fluid contact (claims 1/5/14/29 include that functional limitation).
4) Does the patent cover buprenorphine salts?
Yes. Claims 1, 5, 41 allow buprenorphine as free base or pharmaceutically acceptable salt. Claim 28 and several dependent claims restrict to free base.
5) What dosing schedules are expressly claimed?
Subcutaneous once per month appears in multiple method claims (24-27, 35, 54). Subcutaneous once every three months appears in claim 55 tied to claim 41.
References
[1] US Patent 9,827,241 (claims provided in prompt).
