United States Patent 11,458,134: Scope and Claims Analysis for Crystalline HBr Salt of 1-[2-(2,4-dimethylphenylsulfanyl)-phenyl]piperazine
Executive summary: U.S. Patent 11,458,134 is a formulation-focused IP asset that protects a specific crystalline HBr salt of 1-[2-(2,4-dimethylphenylsulfanyl)-phenyl]piperazine defined by XRPD pattern membership (FIGS. 2–5), plus a tablet composition defined by quantitative excipient ranges (mannitol, microcrystalline cellulose, sodium starch glycolate, magnesium stearate). The claim set also covers method-of-use administration for a defined psychiatric disease basket (with a specific independent emphasis on major depressive disorder). Core infringement risk is highest for products that reproduce (i) the same salt and same crystalline form (XRPD match) and (ii) the same excipient system and weight% bands, especially for tablet dosage forms.
What is claimed in U.S. Patent 11,458,134: crystalline HBr salt composition and tablet formulation?
Direct scope in plain terms: The patent claims a pharmaceutical composition where the active is a hydrobromide (HBr) salt of a specific piperazine-substituted aromatic sulfide compound, but infringement is constrained by the active being a crystalline form that matches an XRPD pattern shown in FIGS. 2–5. The composition also requires specific excipients commonly used for solid oral dosage manufacture: mannitol, microcrystalline cellulose (MCC), sodium starch glycolate (SSG), and magnesium stearate.
Independent claim 1: composition backbone
Claim 1 requires, in combination:
- Drug substance identity
- HBr salt of 1-[2-(2,4-dimethylphenylsulfanyl)-phenyl]piperazine
- Crystalline form limitation
- The HBr salt is a crystalline form characterized by an XRPD pattern as shown in any one of FIGS. 2–5
- Excipients
- Mannitol
- Microcrystalline cellulose
- Sodium starch glycolate
- Magnesium stearate
Practical implication: Claim 1 is not just “any HBr salt.” It is an XRPD-defined crystalline form, creating a strong handle for enforcement based on solid-state characterization.
Dependent claims 2–7: excipient weight% bands
Claims 2–7 narrow claim 1 with quantitative formulation parameters. These are classic composition-range limitations that can be attacked via non-overlapping formulation (by shifting one or more excipients outside the recited bands).
Key ranges:
-
Claim 2 (general ranges):
- Active HBr salt: 2–30 wt%
- Mannitol: 25–45 wt%
- MCC: 22–27 wt%
- SSG: 4–5 wt%
- Magnesium stearate: 0.25–5 wt%
-
Claim 3 (stearate narrowing of claim 2):
- Magnesium stearate: 0.25–2 wt%
-
Claim 4 (one fixed set of ranges):
- Active: 20–22 wt%
- Mannitol: 35–36 wt%
- MCC: 24–25 wt%
- SSG: 3–4 wt%
- Magnesium stearate: 0.25–1 wt%
-
Claim 5 (another set):
- Active: 12–13 wt%
- Mannitol: 36–37 wt%
- MCC: 24–25 wt%
- SSG: 3–4 wt%
- Magnesium stearate: 0.25–1 wt%
-
Claim 6 (another set):
- Active: 25–27 wt%
- Mannitol: 27–29 wt%
- MCC: 24–25 wt%
- SSG: 3–5 wt%
- Magnesium stearate: 0.25–1 wt%
-
Claim 7 (yet another set, low active):
- Active: 3–4 wt%
- Mannitol: 40–42 wt%
- MCC: 26–28 wt%
- SSG: 3–5 wt%
- Magnesium stearate: 0.5 wt% (effectively a narrow point, though written as a range at claim-level: “and magnesium stearate… 0.5%”)
Practical implication: The claim set has both broad “anchor ranges” (claim 2) and multiple narrow embodiments (claims 4–7) that look like specific tablet strengths or manufacturing recipes. A competitor can reduce risk by ensuring at least one excipient weight% falls outside the relevant dependent-claim ranges while also ensuring the XRPD-defined crystalline form is not used.
Claim 8: dosage form
Claim 8 further specifies:
- The composition is a tablet.
Practical implication: The patent is strongest against solid oral tablet products using this exact crystalline form and excipient system. Non-tablet dosage forms (capsules, films, etc.) may fall outside claim 8, though claim 1 still covers a “pharmaceutical composition” unless an infringer can argue product is not a “tablet” for claim 8 but could still infringe claim 1 absent dosage-form limitation. The claim language you provided indicates claim 8 is an additional limitation.
How does XRPD FIGS. 2–5 limit the crystalline HBr salt scope in claim 1?
Claim 1’s crystalline-form limiter is the most infringement-critical feature. It creates a direct evidentiary pathway:
- The active must be the HBr salt.
- It must be a crystalline form characterized by an XRPD pattern “as shown in any of FIGS. 2–5.”
What “any of FIGS. 2–5” means for scope
This phrase expands the claim to multiple crystalline variants that are encompassed by the XRPD patterns in those figures. If FIGS. 2–5 correspond to four discrete XRPD peaksets (e.g., Forms I–IV), then claim 1 covers all of them, but only insofar as the competitor’s product XRPD pattern matches one of the claimed forms.
Key enforcement angle
Because the claim ties the active form to measurable diffraction behavior, infringement analysis can hinge on:
- whether the competitor’s solid state is the same salt form (HBr) and
- whether its crystalline polymorph is one of the claimed XRPD-defined forms.
A competitor attempting to “design around” must target either:
- a non-HBr salt, or
- an HBr salt with an XRPD pattern not matching FIGS. 2–5, or
- an amorphous/other solid form not captured by the asserted XRPD patterns.
What diseases and indications are covered by the method-of-use claims (claim 9 and claim 10)?
Claim 9: disease basket and therapeutic effect
Claim 9 covers administering a therapeutically effective amount of the composition of claim 1 for treating a disease selected from:
- affective disorders
- depression
- major depressive disorder
- anxiety
- general anxiety disorder
- social anxiety disorder
- obsessive compulsive disorder
- panic disorder
- panic attacks
The method requires:
- administration to a patient in need thereof, and
- alleviation of a symptom or complication, or delay of disease progression.
Practical implication: This is a broad psychiatric indication claim set, but still constrained by the composition of claim 1 as the administered drug.
Claim 10: major depressive disorder
Claim 10 narrows claim 9 by specifying:
- disease is major depressive disorder.
Practical implication: It gives the patent a clear foothold for enforcement tied to MDD-labeled products, including filings or marketing directed at that indication.
Where is the patent strongest: crystalline-form first or excipient ranges first?
Answer: Strongest for crystalline-form products, then excipient ranges.
- Claim 1’s XRPD limitation is a “core differentiator” because it limits the active form beyond chemical salt identity.
- Claims 2–7 add formulation concentration limits. If competitors can match the crystalline HBr form but shift excipient weight% out of the recited bands, they may avoid dependent-claim infringement while still risking claim 1 if excipients are present at any amounts (claim 1 does not specify ranges).
- Claim 8 (tablet) increases dosage-form specificity.
Infringement mapping
- To infringe claim 1, the product must contain:
- the same HBr salt and
- the same crystalline XRPD form (FIGS. 2–5),
- plus the four excipients (not necessarily in specific ranges under your claim 1 text).
- To infringe claims 2–7, the product must additionally match the specific wt% bands.
- To infringe claim 8, the product must be a tablet.
- To infringe claims 9–10, the product must be used to treat the listed psychiatric conditions (with MDD specifically for claim 10).
How might competitors design around U.S. Patent 11,458,134?
Design-around levers in descending order
- Avoid XRPD-defined crystalline form
- Use a different polymorph/solid form of the HBr salt not matching FIGS. 2–5, or use a non-HBr salt.
- Shift excipient composition outside dependent claim ranges
- If a competitor uses the same XRPD-defined active, it can potentially avoid dependent-claim coverage by altering one or more excipients outside the recited bands (for the relevant embodiment).
- Change dosage form
- Avoid “tablet” (claim 8), though claim 1 could still be relevant for a non-tablet “composition” if the claim is interpreted broadly as to dosage form.
- Alter indication strategy
- Avoid use for the claimed psychiatric indications. This may be less practical if labeling and prescribing remain within the claim basket. Method-of-use claims typically track approved labeling.
What does the claim structure imply about the patent’s likely commercial coverage?
The excipient system and tablet limitation suggest a product designed for solid oral delivery with standard direct compression ingredients and typical disintegrant (SSG) and lubricant (magnesium stearate). The multiple wt% embodiments in claims 4–7 look like a set of “preferred formulations” that may correspond to multiple strengths or manufacturing optimizations, while claim 2 provides broader coverage.
What patent estate issues follow from this being a formulation-and-polymorph claim?
Licensing and freedom-to-operate posture
- A generic or follow-on seeking a tablet product is exposed to two independent risk axes:
- same active solid form (XRPD) risk for the crystalline HBr salt
- same formulation recipe risk for excipient weight% ranges
Litigation evidentiary posture
- XRPD is likely to be central. Expect characterization-style proof issues: sample prep, comparison methodology, and whether the accused solid state matches one of FIGS. 2–5.
- Excipients are typically easier to quantify from the formulation, but the key is mapping the accused product to the relevant dependent claim embodiment.
Key claim chart: U.S. Patent 11,458,134 coverage elements vs. what to avoid
| Claim element |
What must be present for infringement |
Design-around direction |
| HBr salt identity of specified piperazine sulfide |
Active is the HBr salt |
Use different salt form (non-HBr) |
| Crystalline form defined by XRPD FIGS. 2–5 |
XRPD matches one of the claimed crystalline patterns |
Use different polymorph or amorphous form not captured by FIGS. 2–5 |
| Excipients in claim 1 |
Mannitol, MCC, SSG, magnesium stearate included |
Remove one excipient or alter composition; note claim 1 has no wt% limits in your text |
| wt% constraints in claims 2–7 |
Each accused formulation must fall within the relevant ranges |
Shift excipient wt% outside each dependent-claim band |
| Tablet dosage form (claim 8) |
Product is a tablet |
Use non-tablet dosage form |
| Psychiatric method-of-use (claims 9–10) |
Administer to treat listed conditions (and MDD for claim 10) |
Avoid labeling or medical use matching claimed indications |
Key Takeaways
- U.S. Patent 11,458,134 is anchored on a specific crystalline HBr salt of 1-[2-(2,4-dimethylphenylsulfanyl)-phenyl]piperazine, where the crystalline form is defined by XRPD patterns in FIGS. 2–5.
- The composition coverage is reinforced by excipient requirements, then tightened by wt% ranges in dependent claims (claims 2–7), and by tablet limitation in claim 8.
- Method-of-use claims cover broad psychiatric disease sets, with major depressive disorder singled out in claim 10.
- The highest-risk pathway for competitors is using an identical XRPD-defined crystalline form and then matching excipient recipes; the most effective design-around is changing the solid-state form so XRPD no longer maps to FIGS. 2–5.
FAQs
1. Does the patent cover “any” hydrobromide salt of the compound?
No. Claim 1 requires the HBr salt to be a crystalline form characterized by an XRPD pattern matching FIGS. 2–5.
2. Can a competitor avoid dependent claim infringement by changing only one excipient percentage?
Yes in principle. Claims 2–7 impose specific wt% bands; altering a single component outside the asserted ranges can avoid those narrower claims, though claim 1 still requires the excipient presence (not ranges) plus the XRPD-defined crystalline active.
3. Is major depressive disorder covered even if other psychiatric indications are not?
Yes. Claim 10 specifically targets major depressive disorder as the method-of-use condition.
4. Is the patent limited to tablet dosage forms?
Claim 8 explicitly limits to tablets, but claim 1 covers a “pharmaceutical composition” with required excipients and XRPD-defined active. The strongest dosage-form barrier is for claim 8.
5. What is the most probable “failure point” for a generic attempting to enter with the same API salt?
The crystalline form: if the generic’s XRPD does not match one of the FIGS. 2–5 patterns, the active may fall outside claim 1’s crystalline-form definition.
References
- U.S. Patent No. 11,458,134 (claims as provided).
