US Patent 10,092,561 (Dextromethorphan + Bupropion): Scope, Claims, and Landscape
US Drug Patent 10,092,561 claims a human dosing method for dextromethorphan (DM) in extensive metabolizers, using a daily (once or twice) combination with bupropion for at least eight consecutive days, where the combination produces specific exposure outcomes (AUC and Cmax) on day 8 that are multiples of exposure from DM alone.
What does claim scope cover?
The claimed invention is not a general co-administration of DM and bupropion. It is tightly constrained by all of the following technical and clinical elements:
- Patient phenotype: “an extensive metabolizer of dextromethorphan”
- Indication context: “in need of treatment with dextromethorphan”
- Dosing regimen: “once or twice daily” for “at least eight consecutive days” (with quantitative endpoints evaluated on day 8)
- Combination administration: DM and bupropion are administered in a dosage form (claims are not limited to separate products)
- Exposure targets: day-8 AUC0-12 and/or Cmax windows for DM
- Interaction effect requirement: day-8 DM exposure is at least 15x (AUC) or 15x (Cmax) relative to DM alone given at the same amount for the same duration, on the same day-8 basis
- Dosage-form type (dependent claims): oral, with solid or liquid variants; with immediate-release DM and sustained-release bupropion as an explicit combination-release relationship (claim 29)
This structure makes infringement and validity depend on whether a candidate regimen meets the exposure magnitude and window, not merely whether bupropion inhibits CYP metabolism of DM.
What are the independent claims and their exact limitations?
Claim 1: AUC0-12-based method (DM extensive metabolizers + bupropion)
Claim 1 is the anchor method with AUC0-12 metrics.
Core limitations (as written):
- Treat a human with dextromethorphan
- Administer once or twice daily for at least eight consecutive days a combination of:
- dextromethorphan + bupropion
- Patient is an extensive metabolizer of dextromethorphan
- Human is “in need of treatment with dextromethorphan”
- Combination is administered in a dosage form
- The dosage form provides AUC0-12 of dextromethorphan:
- about 700 to about 1050 ng·hr/mL after eight consecutive days
- After eight consecutive days, DM AUC0-12 is at least about 15x the AUC0-12 that would be achieved by administering the same amount of DM without bupropion for the same eight-day period
Quantitative dependent narrowing inside claim set:
- Claim 10: day-8 AUC0-12 about 750 to 1000
- Claim 11: about 800 to 950
- Claim 12 and 13 are effectively overlapping middle bands:
- Claim 12: about 850 to 900
- Claim 13: about 800 to 900
- Claim 14: about 850 to 950
- Claim 15: about 750 to 950
- Claim 16: at least about 20x DM AUC0-12 versus DM alone
Claim 17: Cmax-based method (DM exposure peak amplification by bupropion)
Claim 17 is the anchor method with Cmax metrics.
Core limitations (as written):
- Treat a human with dextromethorphan
- Administer DM in combination with bupropion:
- once or twice daily for at least eight consecutive days
- Patient is an extensive metabolizer of dextromethorphan
- DM and bupropion administered in a dosage form
- Dosage form provides DM Cmax:
- about 60 to about 110 ng/mL after eight consecutive days
- After eight consecutive days, DM Cmax is at least about 15x Cmax achieved by administering the same amount of DM without bupropion for eight consecutive days
Quantitative dependent narrowing:
- Claim 18: at least 20x Cmax versus DM alone
- Claims 19-24 define multiple day-8 Cmax windows:
- Claim 19: 65 to 105
- Claim 20: 70 to 100
- Claim 21: 75 to 95
- Claim 22: 80 to 90
- Claim 23: 75 to 90
- Claim 24: 80 to 95
How do dependent claims constrain the dosage form and release characteristics?
Oral and solid dosage form constraints (claims 2-5, 25-27)
- Claim 2: dosage form is an oral dosage form
- Claim 3: oral is a solid
- Claim 4: solid includes binder, disintegrating agent, or lubricant
- Claim 5: solid is a tablet, troche, pill, or capsule
- Claim 25: for claim 17, dosage form is also oral
- Claim 26: oral is solid (tablet/troche/pill/capsule)
- Claim 27: solid includes binder/disintegrating agent/lubricant
These are generic excipient and form-factor dependencies. They do not specify specific excipient identities or formulations beyond standard categories.
Oral liquid dosage form constraints (claims 6-7, 28)
- Claim 6: oral dosage form is a liquid
- Claim 7: liquid contains a liquid or solid phase dispersion of bupropion and dextromethorphan
- Claim 28: for claim 17, oral is liquid and comprises liquid or solid phase dispersion of bupropion and dextromethorphan
Release-characteristic constraints (claim 8-9, 29)
- Claim 8 (from claim 1): dosage form is effective for immediate release of dextromethorphan
- Claim 9 (from claim 1): dosage form is effective for sustained release of bupropion
- Claim 29 (from claim 17 chain): oral dosage form is effective for:
- immediate release of dextromethorphan
- sustained release of bupropion
This is a key structural requirement: the DM portion and bupropion portion have different release modalities in the same dosage form.
Scope map: what is “inside” vs “outside” the claim boundaries?
Inside (likely covered)
A candidate product or regimen is within scope if it satisfies all:
- DM + bupropion are administered together in a dosage form
- Patient is an extensive metabolizer phenotype
- Treatment is DM-directed
- Dosing is once or twice daily for at least 8 consecutive days
- Day-8 exposure outcomes match the claim metric(s):
- AUC0-12 about 700-1050 ng·hr/mL (claim 1 baseline)
- and/or DM day-8 Cmax about 60-110 ng/mL (claim 17 baseline)
- and DM day-8 exposure is at least 15x (and optionally 20x) versus the same amount of DM without bupropion
Release characteristics broaden coverage only if they match the dependent limitations (immediate DM + sustained bupropion).
Outside (likely not covered)
A candidate regimen falls outside if any of these fail:
- DM exposure does not reach the required window or fold increase
- regimen duration is less than eight consecutive days
- patient is not an extensive metabolizer phenotype
- DM and bupropion are not administered in the same dosage form (claims repeatedly say “in a dosage form”)
- timing does not support day-8 measurement (if no day-8 evaluation is used, but in practice labels and trials will still generate this endpoint)
Quantitative claim architecture (AUC vs Cmax)
AUC0-12 bands (claim 1 family)
| Claim |
Day-8 AUC0-12 requirement for DM |
Fold condition vs DM alone |
| 1 |
about 700 to 1050 ng·hr/mL |
at least about 15x |
| 10 |
about 750 to 1000 |
at least about 15x (through claim 1) |
| 11 |
about 800 to 950 |
at least about 15x |
| 12 |
about 850 to 900 |
at least about 15x |
| 13 |
about 800 to 900 |
at least about 15x |
| 14 |
about 850 to 950 |
at least about 15x |
| 15 |
about 750 to 950 |
at least about 15x |
| 16 |
(within claim 1 AUC scope via dependency) |
at least about 20x |
Cmax bands (claim 17 family)
| Claim |
Day-8 Cmax requirement for DM |
Fold condition vs DM alone |
| 17 |
about 60 to 110 ng/mL |
at least about 15x |
| 19 |
about 65 to 105 |
at least about 15x |
| 20 |
about 70 to 100 |
at least about 15x |
| 21 |
about 75 to 95 |
at least about 15x |
| 22 |
about 80 to 90 |
at least about 15x |
| 23 |
about 75 to 90 |
at least about 15x |
| 24 |
about 80 to 95 |
at least about 15x |
| 18 |
(within claim 17 Cmax scope via dependency) |
at least about 20x |
Business implication: the claim set is designed to create multiple overlapping “lanes” across exposure bands. This reduces design-around options that rely on small shifts in exposure.
Patent landscape signals and what to check in prosecution history (based on claim mechanics)
This patent’s claims are written in the style of PK-driven combination dosing, where infringement pivots on:
1) phenotype selection (extensive metabolizer),
2) exposure metrics after repeated dosing (day 8 AUC0-12 and Cmax),
3) comparative fold logic (DM alone vs DM+bupropion),
4) formulation release relationship (immediate DM and sustained bupropion, in dependent claims),
5) oral dosage form constraints in dependent claims.
From a landscape perspective, this means the strongest competitor risk is from any product that:
- pairs DM with a CYP2D6 inhibitor (bupropion is the named inhibitor here),
- uses daily multi-day dosing,
- aims for repeated-dose DM systemic exposure in the specified windows.
Key diligence checklist (what landscape mapping should verify)
- Whether competitors use bupropion specifically (not just other inhibitors)
- Whether dosing duration is at least 8 consecutive days with PK evaluation on day 8
- Whether they target DM exposure windows around the claimed AUC and Cmax
- Whether the “same amount” comparator condition is satisfied (regulators and courts will focus on the comparative dosing concept)
- Whether the product is a single dosage form administering DM + bupropion together
- Whether the formulation has the claimed release split:
- immediate DM
- sustained bupropion
Freedom-to-operate logic: how design-around would likely work (and where it will fail)
Most effective design-arounds
- Use a different inhibitor than bupropion (not covered by the literal claim language).
- Avoid dosing for the minimum duration (but this may conflict with clinical strategy and PK accumulation).
- Prevent meeting the fold-increase or exposure window by adjusting dose and/or release. This is difficult because claim windows are broad and there are overlapping dependent windows.
- Use a different patient population (not “extensive metabolizer”), which is hard if the labeled use includes broad genotype/phenotype populations.
Where design-around is hardest
- If a competitor must use bupropion and daily dosing for a week-plus to achieve therapeutic effect, they will naturally produce measurable AUC and Cmax elevations. The claims then “catch” by requiring specific exposure bands and at least 15x fold change.
Litigation posture expectations
- These claims are amenable to PK-centric expert testimony. In enforcement, the central disputes would be:
- measurement method for AUC0-12 and Cmax,
- whether day 8 exposures match windows,
- whether “same amount of DM” is met in comparator studies,
- whether extensive metabolizer status is the relevant population for the accused use.
Key takeaways
- US 10,092,561 claims a human dosing method for dextromethorphan in extensive metabolizers, using bupropion once or twice daily for at least 8 consecutive days.
- Coverage is anchored to day-8 DM exposure:
- AUC0-12 about 700-1050 ng·hr/mL with at least 15x increase vs DM alone (claim 1),
- and/or Cmax about 60-110 ng/mL with at least 15x increase vs DM alone (claim 17).
- Dependent claims create multiple overlapping exposure windows (AUC and Cmax) and tighten fold amplification to 20x.
- Oral dosage form coverage includes solid and liquid embodiments, while formulation-release dependencies require immediate-release DM and sustained-release bupropion.
FAQs
1) Does the patent cover co-administering DM and bupropion as separate products?
The claims repeatedly state DM and bupropion are administered “in a dosage form,” which is read to require a combined dosage-form administration within the claimed method structure, not simply concurrent separate dosing.
2) Is day 8 a hard requirement?
The quantitative AUC0-12 and Cmax requirements are expressly tied to “after eight consecutive days” and specify day-8 endpoints in dependent claims, so day 8 is integral to the measurement conditions.
3) What is the minimum dosing duration in the independent claims?
At least eight consecutive days.
4) How strong is the claim requirement for the magnitude of exposure increase?
It is explicit: at least 15x DM AUC0-12 (claim 1) or Cmax (claim 17) versus the same amount of DM without bupropion for the same 8-day period, with additional dependent coverage at 20x.
5) Do dependent claims limit dosage form type and release?
Yes. Dependent claims limit to oral and specify solid or liquid forms, and they add a release relationship requiring immediate-release dextromethorphan and sustained-release bupropion.
References
[1] Provided claim text for US Drug Patent 10,092,561 (claims 1-29 as supplied by the user).
