Scope and Claims Analysis and US Patent Landscape for U.S. Patent 8,999,313 (Ascorbate plus PEG Colon Cleansing Admixture)
U.S. Patent 8,999,313 covers a two-component or single admix composition for colon cleansing that combines a defined quantity of ascorbate anion (delivered by a controlled molar mixture of ascorbic acid and ascorbate salt) with a defined amount and molecular-weight range of polyethylene glycol (PEG), with optional electrolyte, flavor, sweetener, and packaging in separate components. The claim set is structured around (1) ascorbate anion dose and acid-to-salt ratio, (2) PEG 3000-4000 dose, (3) electrolyte “small salt” add-ons (NaCl/KCl), and (4) a colon-cleansing-use and 500 mL dose context, including a kit format.
What exactly does US Patent 8,999,313 claim for colon cleansing?
High-level claim construction (what must be present)
Independent claim 1 requires, in one composition for admixture with water:
- Ascorbate anion delivery equal to 150 to 400 mmol ascorbate anion, provided by a mixture of:
- (i) ascorbic acid, and
- (ii) one or more ascorbic acid salts
with molar ratio (i):(ii) from 1:4.5 to 1:7.0.
- PEG component: 5 to 100 g PEG with average molecular weight 3000 to 4000 Da.
Every dependent claim refines one or more of these numerical “hinges” (dose, ratio, PEG amount/MW, salt selection, and optional adjuvants like NaCl/KCl/flavor/sweetener), and several narrow further to a 500 mL dose and/or separate packaging.
Claim type mix
- Product composition claims: claims 1, 2-15, 16 (use for 500 mL colon cleansing solution), 17 (separate packaging), 18-29 (additional specific composition embodiments), 24-29 (another specific embodiment), 30 (kit).
- Kit claim: claim 30.
How are the key quantitative limits defined in claim 1?
Ascorbate anion amount: 150 to 400 mmol
Claim 1 sets the ascorbate anion dose as a mmol range. That is a strong infringement lever because alternative ascorbate salts, acid, or mixtures must land in that anion mmol band.
Ascorbic acid vs ascorbate salt molar ratio: 1:4.5 to 1:7.0
The acid-to-salt ratio is the second major numerical “hinge.” This ratio is not expressed in weight percent but in molar terms, meaning reformulation in different salt forms (Na/K/Mg ascorbate) needs stoichiometric control.
PEG amount and molecular weight: 5 to 100 g; 3000-4000 Da
The PEG restriction is both dose and polymer grade:
- Lower bound 5 g prevents trivial inclusion.
- Upper bound 100 g targets a “typical bowel prep” mass.
- PEG MW band (3000-4000) narrows against PEG 3350-only products if the average MW falls outside; it also narrows against larger PEG grades used in some other laxatives/cleansers.
What specific ascorbate formulations are protected in dependent claims 2–7?
These claims lock down ascorbate anion generation via specific acid and specific salt weight ranges (and, indirectly, specific molar outcomes).
Sodium ascorbate versions
- Claim 2: 3.3–12.8 g ascorbic acid + 24.3–69 g sodium ascorbate
- Claim 3: 6.0–10 g ascorbic acid + 40–60 g sodium ascorbate
More narrow sodium embodiment
- Claim 4: 7.0–8.0 g ascorbic acid + 47–56 g sodium ascorbate
Alternative cations (K, Mg)
- Claim 5: 5.0–10 g ascorbic acid + 45–65 g potassium ascorbate
- Claim 6: 5.0–10 g ascorbic acid + 38–57 g magnesium ascorbate
Practical scope note: these dependent claims make it easier to prove infringement if a defendant uses sodium/potassium/magnesium ascorbate within the listed weight bands that correspond to the protected ascorbate anion mmol range and acid:salt molar ratio.
How do claims 8–15 extend the protected product?
Electrolyte add-ons
- Claim 8: add 1.5–4 g sodium chloride
- Claim 9: add 0.75–2.5 g potassium chloride
These are optional limitations but, if present in the accused product, can anchor infringement.
Sulphate exclusion
- Claim 10: “essentially free from alkali metal sulphates or alkaline earth metal sulphates.”
That language can be used as a differentiator in validity and infringement arguments. It is a negative limitation, so a competitor including sulphates risks falling outside “essentially free” depending on how “essentially” is construed.
Flavor/sweetener add-ons
- Claim 11: includes one or more flavoring agents and one or more sweeteners.
- Claim 12: flavoring amount 0.025–1.0 g
- Claim 13: sweetener amount 0.25–2 g
This creates a second “value chain” hook: many commercial bowel preps are flavored/sweetened. If a product uses PEG and the same ascorbate dosing scheme, adding flavors/sweeteners within those ranges strengthens claim fit.
Solid-state / dosage forms
- Claim 14: dry powder/granular/other dry form
- Claim 15: concentrates or slurries
This supports multiple manufacturing formats rather than only a single reconstitution powder.
Where does colon-cleansing context and 500 mL dosing appear?
Claim 16: composition for a 500 mL dose
Claim 16 ties the protected composition to “preparation of a 500 ml or 16 US fluid ounces dose of colon cleansing solution.” That is likely meant to align the composition’s mass to a specific consumer dose size.
Claims 19 and 25: 500 mL in the more specific embodiments
- Claim 19: 500 mL dose for the claim 18 embodiment
- Claim 25: 500 mL dose for the claim 24 embodiment
In practice, these “500 mL” dependent claims can be the most commercially relevant for defending or challenging a specific product packaging configuration.
What does claim 17 and claim 30 add on packaging and kit structure?
Separate packaging
- Claim 17: the ascorbate component and PEG component are packaged separately.
This is a specific structural/commercial limitation. If a competitor sells a single mixed premix powder, claim 17 may not read directly, though claim 1 could still apply if the admixture product composition matches.
Kit claim
- Claim 30: a kit with:
- first component: composition for preparation of a first colon cleansing solution by admixture with water
- second component: a composition for preparation of a second colon cleansing solution by admixture with water, where the second component includes defined ascorbate, PEG, NaCl, KCl, plus flavor and sweetener.
Claim 30 is not only about formulation; it is also about two separate components and a multi-dose or two-prep kit arrangement.
What additional protected embodiments are in claims 18–23 and 24–29?
Claims 18 and 24 read like “formulation exemplars” that are then broken out into dependent limitations. They provide a concrete path to infringement even if the exact claim 1 ranges are met indirectly.
Claim 18 embodiment (specific ranges + pack separate)
Claim 18 adds a structured composition with:
- Ascorbate component:
- (i) 6.0–10 g ascorbic acid
- (ii) 40–60 g sodium ascorbate
- weight ratio (i):(ii) 1:5063 to 1:7.875 (as written; this wording appears to be a transcription/formatting artifact)
- PEG:
- 30–50 g PEG with MW 3000–4000
- Electrolytes:
- 1.5–4 g NaCl and 0.5–3.5 g KCl
- Plus flavor and sweeteners (claims 22–23 specify lists and ranges in dependent form)
- Also claim 18 states packaging may be separate in claim 20.
Dependent refinements:
- Claim 19: 500 mL dose
- Claim 20: ascorbate and PEG packaged separately
- Claim 21: essentially free from sulphates
- Claim 22: flavor types and amount 0.1–0.9 g, with examples: lemon, kiwi, strawberry, grapefruit, orange, fruit punch, mango
- Claim 23: sweetener types and amount 0.25–2 g, with examples: aspartame, acesulfame potassium
Claim 24 embodiment (another fixed-range exemplar)
Claim 24 specifies:
- Ascorbate component:
- 7.43 g ascorbic acid
- 48.11 g sodium ascorbate
- PEG:
- Electrolytes:
- 3.20 g NaCl and 1.20 g KCl
- Flavor and sweeteners included
- Claim 25: 500 mL dose
- Claim 26: ascorbate and PEG packaged separately
- Claim 27: essentially free from sulphates
- Claim 28: flavor 0.1–0.9 g with the same flavor list
- Claim 29: sweetener 0.25–2 g, aspartame and acesulfame potassium
Claim 29 numbering issue (as written)
The claim text says “28 … and 29 …” and also “29 … which comprises 0.25 to 2 g of sweetener, selected from aspartame and acesulfame potassium.” That is consistent as a dependent claim on claim 24/18, but the provided excerpt includes “29” referencing “claim 18” while using claim 18 scope. The infringement approach is still formulation-based: the numeric composition is what matters.
How to read the “scope” for infringement risk: what a generic/biosimilar-style competitor would have to avoid
This is a small “design space” claim set because it anchors on:
- PEG grade band (3000–4000)
- PEG dose (5–100 g in claim 1; 30–50 g in exemplar 18; 40 g in exemplar 24)
- Ascorbate anion dose (150–400 mmol)
- Acid-to-salt molar ratio (1:4.5 to 1:7.0)
- Optional but commercially common exclusions (no alkali/alkaline earth sulphates)
- Optional but commercially common inclusions (NaCl/KCl, flavors, sweeteners)
- Packaging split (claims 17, 20, 26)
- 500 mL dosing (claims 16, 19, 25)
A competitor attempting to “work around” typically changes one of these anchors:
- Swap PEG molecular weight outside 3000–4000
- Reduce PEG mass outside 5–100 g or outside exemplar 18/24 masses
- Replace ascorbate anion system with different redox/acid-salt systems
- Use ascorbate salts/cation forms but shift acid:salt molar ratio out of 1:4.5–1:7.0
- Use different dosing volume context or different total ascorbate anion mmol to avoid 150–400 mmol band
- Include sulphates (risk: “essentially free” fights back)
- Sell a single premix rather than separately packaged components (risk: still potentially within claim 1, but not within the split-pack dependent claims)
What does the patent landscape look like around U.S. Patent 8,999,313 (US validity and design-around pressure)?
No specific prosecution history, listed family members, examiner citations, or expiration/maintenance data is provided in the record you supplied. Without those, a complete landscape mapping cannot be generated with the required precision for litigation-grade work.
What can be concluded from the claim content alone is that the patent is likely part of a cluster around:
- low-volume colon cleansing formulations
- electrolyte-balanced PEG laxatives
- ascorbate salts plus PEG admixture (the “composition for admixture with water” structure)
- flavored sweetened oral bowel preparations
- kit-based split packaging (ascorbate vs PEG)
This structure mirrors how formulation patents are typically prosecuted: broad independent claim with narrow dependent “exemplar” claims that lock in commercially deployed compositions (specific grams, specific sweeteners and flavor types, and 500 mL dosing).
Key takeaways
- Claim 1 is the core barrier: a colon cleansing admixture with 150–400 mmol ascorbate anion generated from ascorbic acid + ascorbate salt at molar 1:4.5 to 1:7.0, plus PEG (3000–4000 Da) at 5–100 g.
- Dependent claims narrow to specific weight ratios/compositions for sodium/potassium/magnesium ascorbate mixtures, and add electrolyte, flavor, sweetener, and sulphate “essentially free” limitations.
- Claims 16/19/25 anchor 500 mL dosing, while claims 17/20/26 and claim 30 anchor split packaging and kit structure.
- Design-around must address at least one of the numeric hinges (ascorbate mmol, acid:salt molar ratio, PEG grade MW, PEG mass) or the negative sulphate limitation plus packaging context.
FAQs
1) Can a colon cleansing product with PEG 3350 avoid infringement by changing PEG molecular weight?
If the accused formulation’s PEG average molecular weight falls outside 3000–4000 Da, it can avoid the literal PEG MW limitation of claim 1 and its dependent embodiments.
2) Does using only sodium ascorbate instead of sodium plus ascorbic acid defeat claim coverage?
Claim 1 requires a mixture of ascorbic acid (i) and ascorbate salt (ii) at a protected molar ratio 1:4.5 to 1:7.0, so eliminating ascorbic acid changes the acid:salt ratio and may fall outside claim scope.
3) Is the 500 mL limitation required for infringement under claim 1?
No. “500 mL” appears in dependent claims (not in claim 1). Claim 1 can be infringed by a composition that meets claim 1’s ingredients and dosing ranges regardless of the dependent 500 mL packaging context.
4) How do flavors and sweeteners affect infringement?
Flavors/sweeteners are optional in claim 1 but are required for claims 11–13 and are specified in the exemplar-dependent claims 22–23 and 28–29. If a product has the same PEG + ascorbate system, flavors/sweeteners can determine whether those dependent claims read.
5) What is the practical meaning of “essentially free from alkali metal sulphates or alkaline earth metal sulphates”?
It is a negative limitation. A product containing sulphate excipients risks falling outside the “essentially free” boundary, affecting whether sulphate-containing formulations meet the dependent claims.
References
No external sources were provided in the prompt, and no additional citationable material (Orange Book listings, patent text source page, prosecution history, maintenance data, or litigation docket) was supplied.
