US Patent 8,207,125: Scope, Claim Coverage, and Practical Patent-Landscape Assessment for Compounds, Citrate Salts, and IV/Injectable Compositions

US Patent 8,207,125 is a formulation-anchored patent that claims (i) a specific compound structure, (ii) pharmaceutically acceptable salts with a specific emphasis on citrate, and (iii) pharmaceutical compositions that recite broad classes of conventional excipients, including cyclodextrins and buffers, and that expressly cover injectable formats (including reconstitutable solids and aqueous IV solutions). The claim set is structured to capture both salt-form variations (citrate) and typical manufacturing/excipient design space (binders/disintegrants/lubricants; sugars/starches/cellulose derivatives; cyclodextrins; buffers; antioxidants such as citric acid; and IV-ready formulations).

Because the active-ingredient identity and full formula are not reproduced in the claim text you provided (the formula is blanked), the analysis below focuses on the claim logic, scope boundaries, and “design-around” implications that are directly inferable from the claim language you supplied.

What is US Patent 8,207,125 claiming: compound formula, citrate salts, and pharmaceutical compositions?

Core coverage in one line: a defined chemical entity (formula), its pharmaceutically acceptable salts with citrate singled out, and pharmaceutical compositions using that compound/salt with conventional carriers, including cyclodextrins and IV/injectable-ready dosage forms.

Independent claims and what they actually lock up

Claim 1: “A compound having the formula: [specific structure].”

Locks the exact compound structure as such.
If another party uses the same compound (or a structure that falls within the literal definition), they implicate this claim.

Claim 2: “A pharmaceutically acceptable salt of a compound having the formula.”

Broad salt claim: any pharmaceutically acceptable salt of the defined compound.

Claim 3: “The pharmaceutically acceptable salt of claim 2, wherein the pharmaceutically acceptable salt is a citrate salt.”

Carves out citrate as a named salt species.
Practical effect: even if a competitor chooses a different salt, citrate-specific formulations remain covered.

Composition claims: how the excipient recitations widen or narrow infringement risk

Claim 4: “A composition comprising a compound having the formula: or a pharmaceutically acceptable salt thereof; and one or more pharmaceutically acceptable carriers.”

This is the broadest composition backbone.
It does not restrict dosage form or excipient identity beyond “pharmaceutically acceptable carriers.”

Claims 5-6: narrow Claim 4 by specifying whether the compound is the free base (claim 5) or the salt (claim 6).

This adds explicit coverage for salt formulations separate from free compound formulations.

Claim 7: composition where carriers are selected from a closed list of excipient categories (binder, disintegrant, lubricant, corrigent, solubilizing agent, suspension aid, emulsifying agent, coating agent, cyclodextrin, buffer).

“Selected from” is typically interpreted as limiting the carrier categories to those enumerated, but still broad inside each category.

Claims 8 and 22: composition where carriers are from an extensive enumerated list (sugars, starches, cellulose derivatives, tragacanth, malt, gelatin, talc, cocoa butter/suppository waxes, oils, propylene glycol, polyols, esters, agar, hydroxide buffers, alginic acid, pyrogen-free water, isotonic saline, Ringer’s solution, ethyl alcohol, phosphate buffer solutions, and “other non-toxic compatible substances”).

This is a standard tactic: it gives the patentee arguments that even “typical formulation excipients” fall within the claim, and it makes it hard for a challenger to argue the formulation is “outside the excipient scope” if the formulation uses common excipients listed here.

Claims 9-11 and 24-26: at least one carrier is a cyclodextrin; at least one is substituted/unsubstituted (3-cyclodextrin; at least one is a buffer.

These are targeted sub-scopes aimed at solubilization strategies that use cyclodextrins (common for poorly soluble actives) and stabilization via buffers.

Optional add-ons that become claim hooks

Claims 12-13 and 27-28: composition further comprises an anti-oxidant, specifically citric acid.

If a competitor includes citric acid as an antioxidant (even when citrate salt is not used), these claims can still trigger.

Claims 14-15: composition further comprises one or more other therapeutic agents, including chemotherapeutic agents.

This supports combination therapy coverage as long as the claimed compound/salt is used in the composition.

Injectable coverage: explicit dosage-form language

Claim 16: composition suitable for intravenous administration.
Claim 18: solid form suitable for reconstitution in a sterile injectable medium.
Claims 19-21 and 29-30: composition comprising compound (or salt) and water; water can be sterile water; and liquid dosage forms (aqueous solution/dispersion/suspension/emulsion) suitable for IV administration.

Practical effect: This patent is not limited to tablets/capsules. It explicitly reaches IV-ready solutions and reconstitutable injectable solids. The water-based claims (19-21, 29-30) are especially relevant because they reduce arguments about whether the formulation “counts” as a composition within Claim 4.

How broad are the claims: literal coverage vs formulation-dependent limitations?

Claim breadth gradient

Claim 1 and 2 (compound and salt): intrinsically broad if the compound identity is met.
Claim 4 (composition with “one or more carriers”): broad but anchored to using the claimed compound/salt.
Claims 7, 8, 22, 23: introduce excipient category and enumerated lists. These can be argued as limitations, but they are drafted to track common excipients, reducing real-world design-around leverage.
Claims 9-11, 24-26: add presence-of-cyclodextrin/buffer requirements. If a product omits these, these narrower claims may not read.
Claims 12-13, 27-28: add antioxidant requirement. If a product does not include citric acid (as antioxidant), these narrower claims may not read.
Claims 16, 18, 29-30: add IV administration and injectable form constraints.

Most likely infringement-positive claim set

If a product uses the same active compound (as defined in the formula) in an injectable formulation, the highest-risk claims are:

Claim 1 (if the product contains the compound itself)
Claim 2-3 (salt choice, particularly citrate)
Claim 4-6 and 19-21 (composition + carriers / water)
Claim 16, 30 (IV suitability)
Claim 9-11 or 24-26 (cyclodextrin and/or buffer presence)
Claim 27-28 (citric acid as antioxidant, if used)

Does US 8,207,125 cover citrate salts specifically, and can competitors avoid by choosing a different salt?

Yes, citrate is explicitly claimed via Claim 3 (citrate salt) and indirectly reinforced by Claim 13/28 (citric acid as antioxidant).

What a “different salt” strategy can and cannot avoid

Switching from citrate to another pharmaceutically acceptable salt may avoid Claim 3 (citrate salt limitation) if the formulation is not citrate.
It does not automatically avoid Claim 2 (any pharmaceutically acceptable salt) or Claim 4/6 (composition using the salt generally).
If the chosen salt is not citrate but the formulation still includes citric acid as an antioxidant, Claim 13/28 can remain in play.

Key point: the claims are not solely about citrate. Citrate is a specific species, but the patent also broadly claims “pharmaceutically acceptable salts” and broadly claims compositions with those salts.

What formulations are protected: cyclodextrin-containing, buffer-containing, antioxidant-containing, and water-based IV injectables?

Cyclodextrin and (3-cyclodextrin

Claim 9/24: at least one carrier is a cyclodextrin.
Claim 10/25: at least one carrier is substituted or unsubstituted (3-cyclodextrin. These are aimed at inclusion complexes and solubilization approaches typical in injectable formulations.

Buffers

Claim 11/26: at least one carrier is a buffer. This matters because many injectable solutions use phosphate, acetate, hydroxide-based or similar systems.

Citric acid antioxidant

Claim 13/28: antioxidant is citric acid. Even if citric acid is used for pH or chelation and described as an antioxidant in the formulation, that can create an additional infringement hook.

Water-based injectables

Claims 19-21: compound/salt + water; water can be sterile water; additional carriers allowed.
Claims 29-30: aqueous solutions/dispersions/suspensions/emulsions; IV suitability.

Design-around reality: Because these claims explicitly cover multiple water-based forms and allow additional carriers, switching from “solution” to “suspension” or “emulsion” is unlikely to remove coverage if the claimed compound/salt and carriers fall within the claim scope.

What patent landscape does US 8,207,125 imply for generics or biosimilar-like competition (even if it is a small molecule)?

This patent itself reads as a small-molecule compound + salts + formulation patent, not a biologic. The practical competitive risk resembles typical “formulation and salt” risk for generics: if an ANDA filer attempts to market the same drug substance (same compound formula) with different excipients, they still face literal claim issues for the salt and composition backbone.

ANDA/Paragraph IV risk profile

If the ANDA product uses the same active compound, it likely falls under Claim 1 (compound) and Claim 4/19 (composition).
If the reference uses citrate, ANDA switching to another salt may try to avoid Claim 3, but Claim 2 and general salt/composition claims remain.
IV and reconstitution form factors are expressly covered, so dosing-form differences likely do not neutralize risk if the active and carrier approach stays within the claim language.

“Salt-only” avoidance strategy is weak

A salt-only change may reduce exposure to the citrate-specific claim (Claim 3), but it cannot remove Claim 2 (general pharmaceutically acceptable salts) or the broader composition claims that cover salts.

Which claim elements create the highest invalidation or narrow-construction pressure points?

Without the full specification and claim construction record, the main analysis is based on structural features of the claim set:

Potentially challengeable areas

Overbreadth in excipient recitations: “one or more pharmaceutically acceptable carriers” plus long lists can attract indefiniteness or enablement scrutiny in some contexts, but these claims look like standard formulation claiming.
(3-cyclodextrin limitation drafting: the claim uses “(3-cyclodextrin” (with the parenthesis formatting in your excerpt). Courts can construe this narrowly if the specification supports a particular stereoisomer/substitution pattern.
Citric acid as both citrate salt and antioxidant: citrate salt (Claim 3) and citric acid antioxidant (Claim 13/28) are not identical but overlap in practice. This redundancy can be argued as capturing multiple functional roles.

Where scope is likely to remain

The compound and salt claim structure (Claims 1-3) typically survives formulation-level arguments because the drug substance is the anchor.
IV suitability (Claims 16, 30) and water-based composition (Claims 19-21, 29) are also hard to avoid if the product is actually injectable and aqueous.

US 8,207,125 claim-by-claim scope map (infringement triggers by product feature)

Claim	What it requires (in plain terms)	Infringement trigger in product design
1	The specific compound (defined by formula)	Active ingredient identity matches
2	Any pharmaceutically acceptable salt of that compound	API is used as a salt form
3	Citrate salt	API salt is citrate
4	Composition with compound or salt + pharmaceutically acceptable carriers	Uses the API and includes conventional carriers
5	Claim 4 where compound is the free base	API used as non-salt
6	Claim 4 where compound is the salt	API used as a salt
7	Carriers selected from enumerated categories including cyclodextrin and buffer	Uses those carrier category types
8	Carriers selected from long excipient list including oils, polyols, buffers, water forms, etc.	Uses conventional excipients from list
9	At least one cyclodextrin carrier	Uses cyclodextrin (any type)
10	At least one (3-cyclodextrin carrier	Uses beta-cyclodextrin
11	At least one buffer carrier	Includes buffer (phosphate etc.)
12	Antioxidant included	Uses antioxidant component
13	Antioxidant is citric acid	Includes citric acid in formulation as antioxidant
14	Other therapeutic agents included	Co-formulated combinations
15	At least one other agent is chemotherapeutic	Includes chemotherapy drug(s)
16	IV administration suitable	Formulated for IV use
17	Hydrated form	Product uses hydrated solid/liquid form as specified
18	Solid reconstitutable to sterile injectable medium	Lyophilized/powder for sterile injection reconstitution
19	Compound (or salt) + water	Water-based composition
20	Water is sterile water	Sterile water used
21	Additional carriers allowed	Any carriers permitted within pharmaceutically acceptable scope
22-23	Similar excipient recitations for “other carriers”	Uses excipient list
24-26	Cyclodextrin / beta-cyclodextrin / buffer presence for other carriers	Similar to claims 9-11 but layered with water composition
27-28	Antioxidant included; citric acid antioxidant	Matches citric acid antioxidant approach
29	Aqueous solution/dispersion/suspension/emulsion	Liquid form factor
30	IV-suitable	IV indication or suitability

How can competitors attempt to design around, and which claim limitations give the best leverage?

Based solely on your claim language, the only “levers” are the presence/absence of specific optional elements (citrate salt; cyclodextrin; buffer; citric acid antioxidant; IV suitability; reconstitutable solid; hydrated form). The anchor claims (compound, salt, and general composition) remain unless the product avoids the claimed compound/salt identity.

Most plausible formulation-level changes

Avoid citrate salt (to target Claim 3 specifically).
Avoid citric acid as antioxidant (to target Claim 13/28).
Avoid cyclodextrins (to target Claims 9-10/24-25).
Avoid buffers (to target Claims 11/26), which is difficult for IV stability and pH control.
Avoid IV-specific form (to target Claims 16/30), which conflicts with injectable IV use.

Limits of design-around

If the product still uses the claimed compound/salt, Claims 2, 4, 6, and 19-21 remain high-risk regardless of which excipients are omitted, because those claims only require “pharmaceutically acceptable carriers” (or water + carriers) without requiring cyclodextrin or citric acid.

Key Takeaways

US Patent 8,207,125 is anchored on a defined compound and then expands to all pharmaceutically acceptable salts plus a citrate-salt species.
The composition claims are broadly framed around conventional formulation carriers, with explicit coverage for cyclodextrins, buffers, and water-based IV/injectable formats, plus optional hooks for citric acid antioxidant and chemotherapeutic combination therapy.
Citrate-only avoidance can at most neutralize the specific citrate claim (Claim 3) but does not remove broader salt and composition coverage (Claims 2 and 4/6).
Excipients changes (removing cyclodextrin/buffer/citric acid) can reduce exposure to narrower dependent claims, but the core “compound/salt + carriers + injectable suitability” scaffolding remains the main risk driver.

FAQs

Do Claims 4 and 19 require cyclodextrin or buffers to infringe?
No. Those are dependent limitations in later claims (e.g., Claims 9-11 and 24-26). Claims 4 and 19 mainly require the defined compound/salt plus pharmaceutically acceptable carriers or water.
If a generic switches from citrate salt to another salt, does it avoid the patent?
It may avoid the citrate-specific dependent claim (Claim 3), but it still risks Claims 2 and the general composition claims that cover pharmaceutically acceptable salts and compositions.
Can a manufacturer avoid infringement by changing the dosage form from IV solution to suspension or emulsion?
Likely not, because the claims expressly cover aqueous solutions, dispersions, suspensions, and emulsions and include IV-suitable language.
Does using citric acid as a pH agent automatically trigger the antioxidant claims?
The dependent claims require citric acid as the antioxidant (Claims 13 and 28). If citric acid is present and characterized/used as an antioxidant in the formulation, those claims are implicated.
Is the patent limited to reconstitutable solids?
No. It covers IV-suitable liquid aqueous compositions (Claims 19-21 and 29-30) and also covers solid forms for reconstitution (Claim 18).

References

United States Patent 8,207,125.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	1781688	⤷ Start Trial	PA2016010	Lithuania	⤷ Start Trial
European Patent Office	1781688	⤷ Start Trial	93015	Luxembourg	⤷ Start Trial
European Patent Office	1781688	⤷ Start Trial	CA 2016 00014	Denmark	⤷ Start Trial
European Patent Office	1781688	⤷ Start Trial	300805	Netherlands	⤷ Start Trial
European Patent Office	1781688	⤷ Start Trial	16C0017	France	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,207,125

Summary for Patent: 8,207,125