US Patent 6,559,188: Scope, Claim Strength, and US Landscape for Nateglinide Composition
US Patent 6,559,188 claims a narrow but formulation-driven composition scope for nateglinide (or a pharmaceutically acceptable salt) combined with specific quantitative ranges of sugar and microcrystalline cellulose (MCC), with dependent claim variations that broaden dosage form and therapeutic use.
What is the claimed invention in one line?
A solid, oral or otherwise pharmaceutically deliverable composition containing nateglinide (0.1 to 35 wt%), sugar (34 to 46 wt%), and microcrystalline cellulose (17 to 23 wt%), where the composition uses defined excipient mass fractions and can be packaged as multiple dosage forms and used for diabetes and body weight decrease.
What do the independent and dependent claims cover?
Claim 1 (core composition formula)
Claim 1 defines the primary infringement boundary by three ingredient classes with hard weight-percentage bands:
| Component |
Range in Claim 1 (wt%) |
Notes |
| Nateglinide or pharmaceutically acceptable salt |
0.1 to 35 |
Broad API loading, but bounded on both ends |
| Sugar |
34 to 46 |
Sugar is a required second excipient class |
| Microcrystalline cellulose (MCC) |
17 to 23 |
MCC is a required third excipient class |
| Basis |
“based on total weight of the composition” |
Weight fractions must sum with other components in the composition to meet the defined ranges |
This claim is a closed formula in the sense that the three categories must meet the stated ranges, but it does not explicitly prohibit other excipients. It anchors infringement primarily on nateglinide + sugar + MCC at specified mass fractions.
Claim 2 (sugar species narrowing)
| Claim |
Sugar definition |
| Claim 2 |
lactose |
This is an additional limitation. A product using another sugar (e.g., sucrose, mannitol, trehalose) can still fall under Claim 1 but not Claim 2.
Claim 3 (MCC tightening)
| Claim |
MCC definition |
| Claim 3 |
21 to 23 wt% |
This is a subset of Claim 1’s 17 to 23 wt%. It tightens infringement if a competitor lands in 17 to 20.9 wt% MCC.
Claims 4–8 (dosage form variants)
These dependent claims add dosage-form labels to Claim 1:
| Claim |
Dosage form limitation |
| Claim 4 |
tablet |
| Claim 5 |
gelatin capsule |
| Claim 6 |
granular composition |
| Claim 7 |
liquid |
| Claim 8 |
suspension |
These are not mutually exclusive in drafting logic, but they control infringement by requiring the product to be made and administered in the claimed physical form. A competitor that uses the same excipient composition but a different dosage form (e.g., film-coated tablet, powder-in-capsule that is not a “granular composition” as construed) may avoid these dependent claims while still risking Claim 1 if the composition itself is used.
Claims 9–10 (therapeutic use)
| Claim |
Use limitation |
| Claim 9 |
treat diabetes |
| Claim 10 |
diabetes is type 2 diabetes |
These claims add medical-use limitations. For infringement analysis in the US, use claims typically require that the product is used in the claimed manner, and the evidentiary record often hinges on labeling, instructions, clinical context, and marketing.
Claim 11 (additional therapeutic effect)
| Claim |
Outcome limitation |
| Claim 11 |
decrease body weight |
This is a functional therapeutic effect claim. It can broaden post-filing exposure because it is not restricted to type 2 diabetes, but it still requires that the composition is used for that effect.
What is the practical claim “landing zone” for competitors?
The bottlenecks are the excipient mass fractions
For Claim 1 infringement, a competitor must make or sell a composition with all three bands simultaneously:
- Nateglinide (0.1–35 wt%)
- Sugar (34–46 wt%)
- MCC (17–23 wt%)
In practice, this means:
- Avoiding the patent is easiest by shifting at least one of the three weight bands outside the stated ranges.
- If the competitor changes sugar identity, that may avoid Claim 2 but not Claim 1.
- If the competitor adjusts MCC fraction, that may avoid Claim 3 while still risking Claim 1 depending on the MCC level relative to 17–23 wt%.
Dosage form affects dependent claim scope
Even if a competitor matches Claim 1 quantitatively, it must also match the dosage form limitation to capture Claims 4–8. For example:
- A formulation meeting Claim 1 and Claim 2 but manufactured as a different delivery system may still fall under Claim 1 but not under the dependent dosage-form claims.
Therapeutic-use claims add labeling/usage vectors
Claims 9–11 create exposure that is often driven by:
- FDA-approved indications (if any)
- OTC or physician instruction language
- Marketing claims tying the product to diabetes treatment and body weight decrease
How broad is Claim 1 relative to typical nateglinide products?
Claim 1 is broad on the API loading (0.1–35 wt%), but it is narrow on the excipient system: sugar must be 34–46 wt% and MCC 17–23 wt%. That is a strong constraint compared with many formulation patents that define method steps or particle properties instead of hard mass-fraction bands.
From a landscape standpoint:
- If the commercial nateglinide market uses substantially different excipient systems (different filler, different binder/filler ratios, or lower MCC fractions), the claim’s practical coverage could be limited.
- If nateglinide products using sugar-based excipients and MCC fall within those exact bands, the claim becomes formulation-blocking.
What are the likely infringement pathways?
Direct composition infringement (Claim 1)
- Making or selling a composition that matches the three mass-fraction bands.
Dependent claim paths
- If sugar is lactose, Claim 2 adds another specific axis.
- If MCC is 21–23 wt%, Claim 3 tightens further.
- If delivered as tablet/capsule/granules/liquid/suspension, Claims 4–8 attach depending on the physical form.
Method/use exposure (Claims 9–11)
- Diabetes and type 2 diabetes use can be tied to prescribing patterns, label indications, and patient instruction.
- “Decrease body weight” is more demanding because a body weight claim requires a credible therapeutic linkage supported by labeling or intended use.
What is the freedom-to-operate (FTO) risk profile within the US?
Risk drivers
- Excipient ratio convergence: matching sugar 34–46 wt% and MCC 17–23 wt% is the central risk driver.
- API loading overlap: most products with nateglinide will likely be within a subset of the 0.1–35 wt% band depending on tablet strength and filler content.
- Dosage form match: the dependent dosage-form claims create additional checkboxes if a product uses a covered physical form.
- Labeling/indication alignment: type 2 diabetes and body weight decrease can trigger use claims.
Risk mitigation levers
- Move sugar content outside 34–46 wt%.
- Move MCC content outside 17–23 wt%.
- Use an excipient system that does not rely on MCC at the claimed mass fraction.
- Use a different dosage form that is arguably not within the dependent claim categories.
- Avoid therapeutic framing tied to the claimed use language (for use claims), assuming the evidentiary record aligns.
How does this patent typically sit in the US formulation landscape?
US formulation patents around older small molecules often cluster into two camps:
- API + excipient quantitative composition claims (like this one).
- process/particle property or co-processed excipient claims.
Claim 1 is structurally closer to the first category. That matters because quantitative composition claims tend to require close matching of formulation composition rather than just demonstrating “similarity.” On the other hand, they can be challenging to design around if the existing commercial formulation already uses sugar and MCC in the claimed ranges.
What is the effective scope: composition only, or also medical use and body weight?
This patent has both:
- Composition scope: Claim 1 and dependent excipient/dosage claims.
- Medical-use scope: diabetes treatment (type 2 specified) and body weight decrease.
The presence of body weight decrease in Claim 11 is a meaningful scope expansion beyond a straightforward diabetes-only composition patent. It can align with broader metabolic claims in marketing or clinical positioning, which can increase the chance that “use” evidence exists.
Claim-by-Claim Scope Matrix (US)
| Claim |
What it adds beyond Claim 1 |
Main design target |
Evasion strategy |
| 1 |
Base formula with ranges for nateglinide, sugar, MCC |
Hit excipient ratios |
Shift sugar or MCC outside bands |
| 2 |
Sugar must be lactose |
Lactose swap |
Use non-lactose sugar |
| 3 |
MCC 21–23 wt% subset |
Tight MCC window |
Use 17–20.9 wt% or >23 wt% |
| 4 |
Tablet |
Dosage form |
Use non-tablet form |
| 5 |
Gelatin capsule |
Dosage form |
Use a different capsule type or format |
| 6 |
Granular composition |
Dosage form |
Use different form factor |
| 7 |
Liquid |
Dosage form |
Use solid forms or suspension if not liquid |
| 8 |
Suspension |
Dosage form |
Use non-suspension form |
| 9 |
Used to treat diabetes |
Indication/use framing |
Avoid diabetes treatment intended use in labeling |
| 10 |
Diabetes is type 2 |
Indication/use framing |
Avoid type 2 use (labeling/usage) |
| 11 |
Decrease body weight |
Indication/therapeutic effect |
Avoid body weight decrease intended use |
Key Takeaways
- Claim 1 is the primary barrier: infringement turns on nateglinide (0.1–35 wt%) + sugar (34–46 wt%) + MCC (17–23 wt%), all based on total composition weight.
- Claims 2 and 3 narrow sugar identity (lactose) and MCC fraction (21–23 wt%) but do not remove the broader Claim 1 risk.
- Claims 4–8 are dosage-form dependent add-ons; they increase exposure only if the product is made/sold in the claimed forms (tablet, gelatin capsule, granular, liquid, suspension).
- Claims 9–11 extend beyond composition into medical use, including type 2 diabetes and body weight decrease, which can raise evidentiary risk through labeling and intended use.
FAQs
1) What part of the claims is hardest to design around?
Claim 1 excipient mass fractions (sugar 34–46 wt% and MCC 17–23 wt%) because they are hard numerical limits tied to the composition itself.
2) If a product uses a different sugar than lactose, does it avoid the patent?
It may avoid Claim 2, but it can still infringe Claim 1 if the sugar is still within 34–46 wt% and MCC stays within 17–23 wt%.
3) Does changing MCC from 22 wt% to 18 wt% avoid infringement?
It avoids Claim 3, but it can still infringe Claim 1 if MCC remains within 17–23 wt%.
4) Can a company avoid dependent dosage-form claims without changing the formula?
Yes, by changing the dosage form to something that is not covered by Claims 4–8, while still evaluating Claim 1 composition risk.
5) How do Claims 9–11 matter for infringement?
They create use-based exposure: diabetes/treatment and type 2 classification (Claims 9–10) and “decrease body weight” (Claim 11) depend on how the product is used and represented.
References
[1] United States Patent 6,559,188.
