Details for Patent: 5,273,995

United States Patent 5,273,995: Claim Scope, Coverage Boundaries, and Landscape

US Drug Patent 5,273,995 claims specific, stereochemically defined small molecules (two alternative structural classes) and then expands coverage through salt forms, a specific sugar-alcohol adduct (“1-deoxy-1-(methylamino)-D-glucitol mixture”), and downstream pharmaceutical use claims tied to hypercholesterolemia. Claim coverage is concentrated around a single core scaffold with defined substitution pattern and tight stereochemical constraints, with the primary “lock” being the recited absolute configurations and ring substituent set.

What do the independent claims actually cover?

Claim 1: the core molecule(s) plus salts

Claim 1 is the key scope anchor. It covers either of two explicitly recited chemical embodiments, plus pharmaceutically acceptable salts:

1) Embodiment A (acid form, stereochemical descriptor):
“[R-(R,R)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic acid”

2) Embodiment B (carboxamide form, different substitution and linkage):
“(2R-trans)-5-(4-fluorophenyl)-2-(1-methylethyl)-N,4-diphenyl-1-[2-(tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-1H-pyrrole-3-carboxamide”

Then Claim 1 also covers “pharmaceutically acceptable salts thereof.”

Scope implication: A competitor cannot avoid Claim 1 merely by switching from acid to base. Claim 1 already includes salt derivatives. Avoidance would require changing at least one of the enumerated structural “hard points” (scaffold, substitution set, or stereochemical definitions).

Claims 2 and 3: narrow to the two single embodiments

• Claim 2 limits to Embodiment A only:
  “[R-(R,R)]-2-(4-fluorophenyl)-β-δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic acid”
• Claim 3 limits to Embodiment B only:
  “(2R-trans)-5-(4-fluorophenyl)-2-(1-methylethyl)-N,4-diphenyl-1-[2-(tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-1H-pyrrole-3-carboxamide”

Scope implication: the patent’s claims are built to be enforceable even if a defendant argues that only one form is implicated; infringement can be mapped to either Embodiment A or Embodiment B.

How do the dependent claims expand coverage?

Salt coverage (Claims 4 to 9)

Claims 4 through 9 cover salts of the compound of Claim 2 (Embodiment A):

• 4. Monosodium salt
• 5. Monopotassium salt
• 6. Hemicalcium salt
• 7. N-methylglucamine salt
• 8. Hemimagnesium salt
• 9. Hemizinc salt

Scope implication: A salt-form strategy does not materially reduce risk if the underlying molecule matches Claim 2. Even multi-equivalent salts (hemi salts) are explicitly claimed.

Specific excipient-formulation complex (Claim 10)

• 10. “The 1-deoxy-1-(methylamino)-D-glucitol mixture with the compound of claim 2”

Scope implication: this is not a generic “any salt with an amine” claim. It is a specific co-form/mixture with 1-deoxy-1-(methylamino)-D-glucitol (commonly associated with N-methylglucamine in naming practice, but here the claim uses the “glucitol mixture” construct). If a product uses a different co-crystal, different polyol, or different stoichiometry outside this defined mixture, it may avoid Claim 10 while still being within or outside the generic “salts” language in Claim 1, depending on the exact chemistry.

What is claimed for medical use?

Pharmaceutical composition claim (Claim 11)

• 11. “A pharmaceutical composition for treating hypercholesterolemia comprising a hypocholesterolemic effective amount of a compound of claim 1 and a pharmaceutically acceptable carrier.”

Coverage:

• composition type: broad “pharmaceutical composition”
• indication: “treating hypercholesterolemia”
• key element: “hypocholesterolemic effective amount” of Claim 1 compound
• excipients: “pharmaceutically acceptable carrier” (generic)

Scope implication: this claim is typically the easiest to satisfy if the drug substance itself matches Claim 1, because formulation carriers are broadly defined.

Method-of-use claim (Claim 12)

• 12. “A method of inhibiting cholesterol synthesis in a human suffering from hypercholesterolemia comprising administering a compound of claim 1 in unit dosage form.”

Coverage:

• method: inhibiting cholesterol synthesis
• patient group: humans suffering from hypercholesterolemia
• act: administer in “unit dosage form”
• active: compound of Claim 1

Scope implication: if the therapeutic effect and administration format align, this claim can be asserted even if a product uses non-identical formulation details, as long as the administration is in unit dosage form and the active matches Claim 1.

Claim scope map: what is tight vs. what is flexible?

Where are the main non-infringement pressure points?

1) Stereochemistry is a central boundary

Claim 1 ties coverage to absolute stereochemical descriptors, including [R-(R,R)] for Embodiment A and (2R-trans) for Embodiment B. Changes to stereochemistry typically move the compound outside the literal claim language.

2) Scaffold and functional group pattern are constrained

Both embodiments specify:

• a 1H-pyrrole core
• a highly substituted arrangement (4-fluorophenyl, phenyl substituents, and multiple additional groups)
• either a heptanoic acid tail (Embodiment A) or a pyran-linked side chain with a carboxamide (Embodiment B)

A design-around would generally need a different scaffold or a different substitution topology, not just minor electronics.

3) Salt coverage is explicit only for Claim 2 salts

Salt claims 4 to 9 cover salts of the Embodiment A molecule (Claim 2). If a product uses a salt of a related but non-identical compound, coverage will fall away unless the compound still qualifies as “the compound of claim 2.”

Patent landscape construction (US 5,273,995)

What you can infer from claim architecture

US 5,273,995 has a classic structure for active-compound IP:

• one or two narrow structural definitions in independent claim 1
• direct dependent claims to the two embodiments and specific salts/mixtures
• downstream product and method claims anchored to the same structure

That means the enforceable “center of gravity” is the drug substance identity in Claim 1, not the packaging or formulation.

Likely landscape implications for competitors

• If the competitor’s API matches Embodiment A or B exactly (including stereochemistry), infringement risk is high across chemical, salt, and use claims.
• If the competitor’s API differs only by salt form, risk remains high because Claim 1 covers “pharmaceutically acceptable salts thereof,” and claims 4 to 9 add explicit Embodiment A salts.
• If the competitor differs by stereochemistry or by swapping the acid vs. carboxamide embodiment while preserving the rest of the scaffold, it still may fall under Claim 1 if the other embodiment is recited. The design-around target is therefore not only the salt or counterion but the entire structural definition.

Practical freedom-to-operate lens (in-claim)

The claims create a straightforward freedom-to-operate test set:

1. Does the product contain a compound that matches Claim 1’s Embodiment A or Embodiment B exactly?
2. If Embodiment A: does the product use one of the claimed salts or “glucitol mixture” (Claims 4-10) or a pharmaceutically acceptable salt generally (Claim 1)?
3. Does the product label/market/use align to hypercholesterolemia treatment and/or cholesterol synthesis inhibition in humans, with unit dosage administration?
4. Is there an intention to practice unit-dosed administration? This matters for Claim 12.

Key Takeaways

• Claim 1 is the enforceable core: it covers two explicitly defined, stereochemically constrained drug structures (Embodiment A acid and Embodiment B carboxamide), plus pharmaceutically acceptable salts.
• Salt and mixture claims are broad in the defined perimeter: explicit Embodiment A salts (Na, K, Ca, N-methylglucamine, Mg, Zn) and a specific “1-deoxy-1-(methylamino)-D-glucitol mixture” are claimed.
• Medical use IP follows the chemistry: composition (Claim 11) and cholesterol-synthesis inhibition method (Claim 12) are anchored to Claim 1 compounds.
• Design-around pressure points are structural and stereochemical, not just formulation: avoiding infringement generally requires moving outside the exact scaffold/substitution/stereochemical definitions of Embodiment A and/or Embodiment B.

FAQs

1) Are salts of the claimed compound covered even if they are not listed in Claims 4-10?
Yes for “pharmaceutically acceptable salts thereof” in Claim 1, but the explicit salt list in Claims 4-10 targets salts of the Claim 2 (Embodiment A) compound.

2) Does Claim 11 require a specific formulation technology?
No. It only requires a “hypocholesterolemic effective amount” of a Claim 1 compound and a “pharmaceutically acceptable carrier.”

3) Does Claim 12 require a particular dosing frequency?
No. It requires administration in “unit dosage form” to humans suffering from hypercholesterolemia to inhibit cholesterol synthesis.

4) Is Embodiment A or Embodiment B the primary target for enforcement?
Both are directly claimed in Claim 1, with Claims 2 and 3 narrowing to each embodiment. Enforcement can track whichever embodiment a product uses.

5) Can a competitor avoid infringement by switching from an acid to a carboxamide form only?
Not automatically. Claim 1 covers both acid (Embodiment A) and carboxamide (Embodiment B) structures as alternative recitations.

References

[1] United States Patent 5,273,995. Claims as provided in prompt.