Details for Patent: 7,820,788

United States Patent 7,820,788 (Paclitaxel + Albumin Nanoparticles, Cremophor-Free): Scope, Claims, and Landscape

What does US 7,820,788 claim in concrete terms?

US 7,820,788 is directed to an injectable (and broadly usable) pharmaceutical composition in which paclitaxel is formulated with albumin as particles having a particle size < about 200 nm, with an albumin:paclitaxel weight ratio ranging from about 1:1 to about 9:1. The claims also require the composition to be formulated free of Cremophor (claim 3) and cover methods of treating cancer, arthritis, and restenosis using the composition (claims 4-7), with broad administration routes (claims 8-9).

Claim 1 is the anchor. It sets all material limitations:

• Drug substance: paclitaxel
• Carrier: pharmaceutically acceptable carrier comprising albumin
• Formulation state: albumin and paclitaxel are formulated as particles
• Particle size: < about 200 nm
• Ratio: w/w albumin:paclitaxel about 1:1 to about 9:1

Claims 2, 3, and 10-12 narrow the albumin identity, excipient freedom, and ratio subranges. Claims 4-9 expand the protected use.

What are the exact claim limitations across the independent and dependent claims?

Claim 1 (independent): composition scope

1. “A pharmaceutical composition for injection comprising paclitaxel and a pharmaceutically acceptable carrier, wherein the pharmaceutically acceptable carrier comprises albumin, wherein the albumin and the paclitaxel in the composition are formulated as particles, wherein the particles have a particle size of less than about 200 nm, and wherein the weight ratio of albumin to paclitaxel in the composition is about 1:1 to about 9:1.”

Key scope levers and what they do:

• “for injection”: limits product to injectable formulation context even though downstream method claims include many routes.
• “albumin and paclitaxel … formulated as particles”: requires a particulate formulation. This is not just “paclitaxel with albumin present”; it is a particulate system where both components are part of the particle-forming structure.
• Particle size < 200 nm: establishes a nanoscale boundary. Any design choice that moves particle size above that threshold avoids literal infringement of claim 1.
• Albumin:paclitaxel 1:1 to 9:1 (w/w): establishes a compositional boundary. A formulation outside this ratio avoids literal infringement.

Claim 2: albumin identity

2. “The pharmaceutical composition of claim 1, wherein the albumin is human serum albumin.”

This narrows to human serum albumin (HSA). A formulation using non-human albumin (or recombinant albumin with different sourcing) can potentially avoid claim 2 even if it meets claim 1.

Claim 3: excipient limitation (Cremophor-free)

3. “The pharmaceutical composition of claim 1, wherein the pharmaceutical composition is free of Cremophor.”

This creates a bright-line excipient requirement. Any paclitaxel formulation that uses Cremophor (e.g., Cremophor EL) is outside claim 3, and therefore outside the dependent claims that incorporate it.

Claims 4-7: medical use

4. “A method of treating a disease comprising administering an effective amount of a pharmaceutical composition of claim 1, wherein the disease is cancer, arthritis, or restenosis.”

5. cancer
6. arthritis
7. restenosis

These define the protected therapeutic indications. Coverage is tied to using the claim 1 composition.

Claims 8-9: administration routes

8. “... administered intravenously, intraarterially, intrapulmonarily, orally, by inhalation, intravesicularly, intramuscularly, intra-tracheally, subcutaneously, intraocularly, intrathecally, or transdermally.”

9. “wherein the pharmaceutical composition is administered intravenously.”

Claim 8 is extremely broad for route, while claim 9 tightens to IV. In practice, while route breadth expands enforcement surface, composition-specific limitations (particle size, ratio, particle state) still govern infringement.

Claims 10-12: ratio subranges

10. about 1:1 to about 5:1
11. 1:1 to 9:1
12. about 9:1

These depend on claim 1 and refine ratio within that overall envelope. Claim 11 largely restates the full range in claim 1, while claim 12 locks onto a high-albumin end point.

Where is the patent’s practical “infringement perimeter”?

For a formulation to fall within claim 1, it must satisfy all of the following simultaneously:

1. Paclitaxel + albumin in a pharmaceutically acceptable carrier
2. Both albumin and paclitaxel formulated as particles
3. Particle size < about 200 nm
4. w/w albumin:paclitaxel = about 1:1 to about 9:1
5. Intended as a composition “for injection”

For enforcement, the hardest-to-design-around features tend to be particle size and the particle formulation requirement. Companies can often change excipients, albumin source, or dose form, but particle engineering is the central technical boundary.

What design-arounds are implied by the claim text?

Because the claims are composition-defined and include quantitative thresholds, the most direct design-outs are:

• Increase particle size to ≥ about 200 nm (avoids literal “less than about 200 nm”)
• Move albumin:paclitaxel outside 1:1 to 9:1 (avoids literal ratio)
• Use an excipient that includes Cremophor to avoid “free of Cremophor” (relevant for claim 3 and any dependent reliance)
• If asserting on dependent claim 2, use non-HSA albumin (relevant to claim 2 only)

However, methods claims (4-9) tether infringement to the use of the claim 1 composition, so route changes do not salvage a nonconforming formulation.

How does the claim set map to the market for albumin-bound paclitaxel?

The patent’s structure tracks the core idea of albumin-based, Cremophor-free paclitaxel nanoparticulate formulations. The ratio and particle-size limits suggest a targeted formulation space rather than a generic “albumin-bound” concept.

Claim coverage matrix (literal scope)

What is the likely patent landscape around this claim theme?

US 7,820,788 sits in the broader albumin-bound paclitaxel and Cremophor-free paclitaxel formulation space. The key competitive set typically includes:

• Albumin-bound paclitaxel branded products (and their formulation patents)
• Other nanoparticle paclitaxel systems that use different carriers but may still fall into similar particle-size windows
• Cremophor-free solvent-based approaches that avoid albumin particle requirements

Within that landscape, US 7,820,788’s differentiators are the specific combination of:

• Particle size (< 200 nm)
• Particle formulation requirement (“albumin and paclitaxel … formulated as particles”)
• Albumin:paclitaxel w/w ratio (1:1 to 9:1)
• Optional excipient constraint (Cremophor-free via claim 3)
• Broad use claims (cancer, arthritis, restenosis) and broad route in methods

Scope risks and enforceability pressure points

1. “Less than about 200 nm”
   The use of “about” introduces tolerance, but it still creates a quantitative boundary. Formulations engineered slightly above 200 nm can test the line.

2. “Albumin and paclitaxel … formulated as particles”
   If the formulation has free paclitaxel, separate non-overlapping drug particles, or only albumin particles with paclitaxel adsorbed without the claimed particle formation relationship, it can become a factual and technical dispute.

3. Albumin:paclitaxel ratio is narrow relative to typical formulation freedom
   Many formulations can adjust drug loading by weight percent. Claim 1 ties the allowable range tightly to albumin:paclitaxel by weight.

4. Method claims are broad on route but narrow on composition
   A company that changes only dosing route (e.g., oral vs IV) does not avoid infringement if the claim-1 composition is used.

Key Takeaways

• US 7,820,788 claim 1 is a tightly defined paclitaxel-albumin nanoparticle composition with particle size < about 200 nm and w/w albumin:paclitaxel about 1:1 to about 9:1, where both components are formulated as particles.
• Dependent claims narrow to HSA (claim 2), Cremophor-free (claim 3), and specific albumin:paclitaxel subranges (claims 10-12).
• Method claims (claims 4-9) are broad on route but confined to administration of the claim 1 composition for cancer, arthritis, or restenosis.
• The practical infringement perimeter is governed by particle engineering and weight-ratio selection, not by therapeutic indication wording alone.

FAQs

1) What is the single most important claim in US 7,820,788?

Claim 1. It sets the full composition definition: paclitaxel + albumin particles, particle size < about 200 nm, and albumin:paclitaxel w/w ratio about 1:1 to about 9:1.

2) Does changing the administration route avoid infringement?

Not if the administered product still meets claim 1. Routes are covered broadly in the method claims (claim 8) as long as the composition used is the claim 1 composition.

3) Is Cremophor absence required for all claim coverage?

No. Cremophor-free is required in dependent claim 3. Claim 1 itself does not include a Cremophor-free limitation.

4) Can a formulation avoid claim 1 by changing albumin source?

Avoiding claim 1 depends on whether all other features remain. Claim 2 specifically requires human serum albumin, so changing albumin source can avoid claim 2 while still potentially falling under claim 1.

5) Which parameters are most feasible for design-around?

The claim text points to particle size (to get to ≥ about 200 nm) and albumin:paclitaxel ratio (to get outside 1:1 to 9:1) as the most direct design-arounds.

References

[1] United States Patent No. 7,820,788. “Pharmaceutical composition for injection comprising paclitaxel and albumin particles” (claim set provided in prompt).