US Patent 10,624,879: Scope of Claims, Claim-Construction Anchors, and Landscape
United States Patent 10,624,879 claims a specific liquid formulation built around sodium picosulfate plus a defined counterion/acid stabilization system: magnesium oxide (MgO), citric acid (CA), and malic acid (MA), with strict pH (4.1 to 5.4) and composition stability metrics after storage at room temperature for 24 months. The dependent claim set tightens the formulation to a weight-ratio window, and it adds functional stability limits via two measured phenomena: “Substance A” generation (as a sodium picosulfate related species) and precipitation volume.
What is the core invention scope? (Independent claim coverage)
Claim 1 (baseline composition identity + pH)
Claim 1 is the primary claim that defines the scope:
- A pharmaceutical composition comprising:
- sodium picosulfate
- magnesium oxide
- citric acid
- malic acid
- The composition is a solution
- pH range: 4.1 to 5.4
Scope implication: The claim is anchored on a 4-component formulation and an acidified liquid state. It does not, by itself, constrain:
- concentration ranges (except via dependent ratio claims),
- specific excipient identities,
- storage container or method,
- the nature of “Substance A” beyond it being “related to sodium picosulfate,”
- the storage conditions beyond the dependent claims’ 24-month aging test.
Claim 11 (parallel independent claim with a single narrower ratio)
Claim 11 is also independent, and it duplicates most of claim 1’s structural elements while adding a defined ratio:
- A pharmaceutical composition comprising:
- sodium picosulfate, magnesium oxide, citric acid, malic acid
- The composition is a liquid (explicit)
- pH range: 4.1 to 5.4
- weight ratio (approx): 0.005 : 1.75 : 6 : 4.19
- (sodium picosulfate : MgO : citric acid : malic acid)
Scope implication: Claim 11 is narrower than claim 1 because it adds a specific ratio, but it may be used as a stronger validity anchor if claim 1 is found broad or obvious.
How do the ratio claims narrow the formulation space?
Weight ratio window in claim 2 (broad dependent tightening)
Claim 2 requires the same four components as claim 1, but constrains their relative amounts to a window:
- sodium picosulfate : magnesium oxide : citric acid : malic acid
0.003 to 0.009 : 1 to 3 : 3.5 to 10.5 : 0.01 to 13
Interpretation in landscape terms: This creates a formulation “box” within which pH still must sit between 4.1 and 5.4 (per claim 1), and which must also survive the stability requirements if those dependent claims are asserted.
Specific ratio in claim 11 (tight dependent tightening)
Claim 11 hardcodes an approximate point:
This is a single ratio target that can be used to:
- differentiate from nearby formulations,
- support enforceability against close variants that fail the exact ratio.
What are the stability and failure-mode requirements that drive practical infringement risk?
Claims 3, 4, 12, and 13 introduce two measurable constraints after a stability challenge: room temperature aging for 24 months.
Substance A generation limit (claims 3 and 12)
- Claim 3 (for claim 1 compositions):
- “Substance A related to sodium picosulfate is generated” at:
- about 2.0 wt. % or less after room temperature storage for 24 months
- Claim 12 mirrors the same limit for claim 11:
- about 2.0 wt. % or less after 24 months at room temperature
Landscape implication: Even if a competitor matches the four components and pH, it may avoid infringement if it does not meet the Substance A threshold. This creates a stability-based claim boundary that is often harder to design around without measurement data.
Precipitation limit (claims 4 and 13)
- Claim 4:
- precipitation occurs at:
- about 5.0 vol. % or less after 24 months at room temperature
- Claim 13:
- same precipitation constraint for claim 11
Landscape implication: This also creates a hard acceptance criterion for long-term physical stability. A close formulation variant that slightly shifts solubility or salt/acid interactions may fail this threshold and avoid coverage.
How do excipient claims affect scope and design-around?
Claims 5 and 14 allow excipients from a listed functional bucket.
Generic excipient bucket (claims 5 and 14)
- Claim 5 (dependent on claim 1)
- Claim 14 (dependent on claim 11)
- Both say the composition further comprises one or more excipients chosen from:
- pH adjusters
- stabilizers
- preservatives
- sweeteners
- fragrance ingredients
Key point for infringement: This is an inclusion-style dependency. It does not limit the claims to those excipients only; it specifies permissible excipients, which may make it easier to argue infringement if the accused product includes standard sweeteners/preservatives and the core four-component system and pH are met.
Specific excipients as additional dependencies
Claims 6-10 and 15-19 enumerate individual additives:
- acesulfame potassium (claims 6 and 15)
- disodium edetate (claims 7 and 16)
- sodium benzoate (claims 8 and 17)
- sodium hydroxide (claims 9 and 18)
- sucralose (claims 10 and 19)
Practical effect:
- These dependent claims increase coverage likelihood against commercially typical flavor/preservative systems.
- They also allow narrower enforcement if an accused product includes one or more of these additives but differs in others.
Claim matrix: what a product must contain to fall within each claim
| Claim |
Required composition elements |
pH constraint |
Ratio constraint |
Stability constraint(s) |
Typical additional excipients in dependent claims |
| 1 |
Na picosulfate + MgO + CA + MA |
4.1 to 5.4 |
none (beyond dependent 2) |
none (until claims 3-4) |
optional (via claim 5) |
| 2 |
same as claim 1 |
4.1 to 5.4 |
0.003 to 0.009 : 1 to 3 : 3.5 to 10.5 : 0.01 to 13 |
none (until 3-4) |
optional (via 5) |
| 3 |
same as claim 1 |
4.1 to 5.4 |
none |
“Substance A” ≤ about 2.0 wt.% after 24 months room temp |
none |
| 4 |
same as claim 1 |
4.1 to 5.4 |
none |
precipitation ≤ about 5.0 vol.% after 24 months room temp |
none |
| 5 |
same as claim 1 |
4.1 to 5.4 |
none |
none |
excipients from the bucket list |
| 6-10 |
same as claim 1 |
4.1 to 5.4 |
none |
none |
includes specific excipients (Ace-K, edetate, benzoate, NaOH, sucralose) |
| 11 |
same four components |
4.1 to 5.4 |
about 0.005 : 1.75 : 6 : 4.19 |
none (until 12-13) |
optional (via 14) |
| 12 |
same as claim 11 |
4.1 to 5.4 |
about 0.005 : 1.75 : 6 : 4.19 |
Substance A ≤ about 2.0 wt.% after 24 months room temp |
none |
| 13 |
same as claim 11 |
4.1 to 5.4 |
about 0.005 : 1.75 : 6 : 4.19 |
precipitation ≤ about 5.0 vol.% after 24 months room temp |
none |
| 14 |
same as claim 11 |
4.1 to 5.4 |
about 0.005 : 1.75 : 6 : 4.19 |
none |
excipients from bucket list |
| 15-19 |
same as claim 11 |
4.1 to 5.4 |
about 0.005 : 1.75 : 6 : 4.19 |
none |
includes specific excipients |
How should “Substance A” be treated in enforcement and invalidity arguments?
“Substance A related to sodium picosulfate” is a measured degradation marker. The claim uses:
- a relative definition (“related to sodium picosulfate”),
- a quantitative threshold (≤ about 2.0 wt.%),
- a test condition (left at room temperature for 24 months).
Scope consequences
- If a challenger can show a prior art formulation already meets the same stability thresholds under the same test regime, the stability-dependent claims could be vulnerable.
- If “Substance A” is not clearly distinguishable in the prior art, then the practical risk shifts to the need for matching analytical definitions.
Enforcement consequences
- In an infringement scenario, proving “Substance A” level and precipitation volume after exactly the same aging window becomes central.
- A close formulation that matches pH and ratios but generates more than about 2.0 wt.% “Substance A” is outside claims 3/12 even if it is otherwise similar.
Patent landscape: where this claim set typically sits vs likely prior art
A full, authoritative landscape for US 10,624,879 requires access to:
- its bibliographic record (assignee, filing date, priority chain),
- prosecution history (citations, examiner reasoning),
- the complete specification (examples, analytical methods, “Substance A” identity),
- and a mapped set of related sodium picosulfate liquid formulations.
That information is not present in the provided material. Under strict constraints, a complete landscape with named competitor patents and their claim coverage cannot be generated.
What can be stated strictly from the claim text you supplied is the practical novelty angle that the patent is trying to claim in the marketplace:
Likely novelty lever(s) embedded in the claims
- Liquid sodium picosulfate with acidic pH 4.1 to 5.4
- MgO + dual organic acids (citric + malic)
- Specific weight-ratio constraints (wide window and a tight point ratio)
- Long-term physical and chemical stability tests
- “Substance A” generation threshold
- precipitation volume threshold
- Allowance for standard excipient sets typical for oral liquids, including preservatives and sweeteners
How competitors can design around (based on claim boundaries alone)
- Change pH outside 4.1 to 5.4 (hard design-around).
- Change the four-component set (remove MgO or one of the acids).
- Keep the same chemistry but move outside the ratio bounds (for claim 2/11).
- Match chemistry and ratio but fail the stability thresholds:
- raise “Substance A” above about 2.0 wt.% after 24 months room temperature, or
- allow precipitation above about 5.0 vol.% after the same period.
- Use the same components but with a formulation state that is not a “solution/liquid” as claimed (unlikely to be effective if the product is marketed as an oral liquid).
What the claims do not cover (important for scope boundaries)
Based solely on the provided claim text, the patent does not explicitly claim:
- solid dosage forms (tablets, granules),
- different laxative salts or combinations beyond sodium picosulfate,
- different pH ranges (outside 4.1 to 5.4),
- different storage stability challenges (only room temperature for 24 months is used in these dependent limits),
- administration method claims (no regimen/dosing claims are shown).
Key Takeaways
- US 10,624,879 is centered on a four-component sodium picosulfate liquid formulation using MgO + citric acid + malic acid at pH 4.1 to 5.4.
- The independent claim set is split between:
- claim 1 (composition + pH), and
- claim 11 (composition + pH + a specific ratio 0.005 : 1.75 : 6 : 4.19).
- Two dependent claim pairs create stability-based infringement fences after 24 months room temperature:
- “Substance A” ≤ about 2.0 wt.%
- precipitation ≤ about 5.0 vol.%
- Dependent excipient claims cover common oral-liquid additives including acesulfame potassium, disodium edetate, sodium benzoate, sodium hydroxide, and sucralose, plus an allowed excipient bucket.
- A complete named patent landscape cannot be produced from the claim text alone; the claim wording indicates the patent’s likely differentiation is stability + pH + MgO/citric/malic system + ratio constraints.
FAQs
1) Does the patent cover any sodium picosulfate solution at pH 4.1 to 5.4?
Only if it also contains magnesium oxide, citric acid, and malic acid in the claimed liquid/solution context.
2) What is the significance of “Substance A” in the claims?
Claims 3 and 12 require “Substance A” (defined as “related to sodium picosulfate”) to be ≤ about 2.0 wt.% after 24 months at room temperature.
3) Can a competitor infringe by matching pH and ingredients but using different ratios?
Claim 1 can still be implicated if ingredients and pH match; however, claim 2 and claim 11 add ratio constraints that narrow coverage.
4) What stability test is used to limit precipitation in the formulation?
Claims 4 and 13 require precipitation ≤ about 5.0 vol.% after 24 months at room temperature.
5) Do the claims restrict excipients?
They permit excipients chosen from defined functional categories (claims 5 and 14) and also include dependent coverage for several specific additives (claims 6-10 and 15-19).
References
[1] US Patent 10,624,879 (claims provided in prompt).
