United States Patent 7,658,914: Scope, Claims, Expiration and Patent Landscape for PEG-Ascorbate Bowel-Preparation Kits

U.S. Patent No. 7,658,914 protects a low-volume bowel-cleansing formulation combining PEG 3350, sulfate, sodium chloride, potassium chloride, ascorbic acid and an ascorbate salt. Its strongest claims cover the specific MoviPrep-type formulation supplied in separate sachets and reconstituted in water. The patent’s projected 20-year term runs to December 22, 2025, based on the earliest nonprovisional filing date identified for the family. The core commercial risk is concentrated in exact or near-exact copies of the disclosed PEG-ascorbate composition, rather than in all PEG-based bowel preparations.

What product does U.S. Patent 7,658,914 protect?

The patent covers a bowel-cleansing kit and the resulting aqueous solution. The claimed formulation is characterized by:

Component	Broad claimed range	Specific formulation
PEG, preferably PEG 3350	90-125 g	100 g
Sulfate salt	5-10 g	7.5 g sodium sulfate
Sodium chloride	2-4 g	2.691 g
Potassium chloride	0.5-1.3 g	1.015 g
Ascorbate component	5-15 g	4.7 g ascorbic acid plus 5.9 g sodium ascorbate
Total dissolved species	300-700 mmol/L	Within the narrower claimed range
Flavoring	Optional	0.340 g lemon flavor
Sweeteners	Optional	0.233 g aspartame plus 0.117 g acesulfame K
Packaging	One or two sets of containers	Sachets are expressly claimed

The formulation corresponds to the composition used in MoviPrep, a prescription bowel-cleansing product originally associated with Norgine and commercialized in the United States through Salix Pharmaceuticals.[1]

What are the independent claims in U.S. Patent 7,658,914?

The patent has three principal independent claim categories.

Claim 1: Broad two-container kit

Claim 1 requires:

A first container containing a dry PEG-electrolyte composition;
PEG in the amount of 90-125 g;
Sulfate in the amount of 5-10 g;
Sodium chloride in the amount of 2-4 g;
Potassium chloride in the amount of 0.5-1.3 g;
A second container containing 5-15 g of an ascorbate component;
The ascorbate component comprising ascorbic acid and an ascorbate salt;
An ascorbic acid-to-salt weight ratio of 2:8 to 8:2; and
A calculated dissolved-species concentration of 300-700 mmol/L after reconstitution.

This is a combination claim. A product must satisfy the container architecture, ingredient classes, concentration ranges, ratio requirement and calculated osmolar-species limitation to fall within the literal scope of claim 1.

Claim 10: Exact quantitative kit

Claim 10 narrows the invention to:

100 g PEG 3350;
7.5 g sodium sulfate;
2.691 g sodium chloride;
1.015 g potassium chloride;
4.7 g ascorbic acid; and
5.9 g sodium ascorbate.

Unlike claim 1, claim 10 does not expressly recite the dissolved-species limitation. It also does not expressly require the ascorbate material to be in a separate second container through the wording supplied, although the claim does require a first container and a second container with the specified compositions.

Claim 10 is materially narrower in ingredient amounts but potentially easier to analyze in litigation because it uses fixed quantities rather than broad numerical ranges.

Claim 17: Exact composition with flavoring and sweeteners

Claim 17 requires the exact formulation in claim 10 and further requires the first dry composition to consist of:

0.233 g aspartame;
0.117 g acesulfame K; and
0.340 g lemon flavor.

The use of “consisting of” creates a closed-composition limitation for the recited first and second dry compositions. Unlisted ingredients may create a noninfringement argument if they are present in material amounts or alter the claimed composition. The effect depends on claim construction and whether the additional material is treated as an impurity, processing aid or substantive ingredient.

How broad is the scope of claim 1?

Claim 1 has meaningful breadth, but its limitations operate cumulatively.

Ingredient class coverage

The sulfate limitation covers:

Alkali metal sulfates, such as sodium sulfate or potassium sulfate;
Alkaline earth metal sulfates, such as magnesium sulfate or calcium sulfate; and
Mixtures of those salts.

The claim therefore is not limited to sodium sulfate. A competing product using magnesium sulfate could satisfy the sulfate-class limitation if the amount and remaining limitations are met.

The ascorbate limitation is also broader than the specific MoviPrep formulation. It covers an ascorbic acid/ascorbate-salt combination in a 20:80 to 80:20 weight ratio. Sodium ascorbate is the disclosed example, but the claim language can reach other salts, depending on the specification and claim construction.

Quantitative limitations

The numerical ranges are central to infringement analysis:

PEG: 90-125 g;
Sulfate: 5-10 g;
Sodium chloride: 2-4 g;
Potassium chloride: 0.5-1.3 g;
Ascorbate component: 5-15 g;
Ascorbic acid-to-salt ratio: 2:8 to 8:2;
Dissolved species: 300-700 mmol/L.

A formulation outside one range may avoid literal infringement of claim 1. The doctrine of equivalents could still be asserted, but prosecution-history estoppel and the numerical nature of the limitations would present significant constraints.

The ranges are generally open-ended only as to additional ingredients. They are not open-ended as to the required amounts. A product with 130 g PEG, for example, would not literally satisfy the 90-125 g PEG limitation.

What does the dissolved-species limitation require?

The claims do not simply recite osmolality. They require a calculated total number of moles of individual dissolved species per liter.

This limitation appears directed to the ionic and molecular species produced when the dry compositions are dissolved in water. For example:

Sodium sulfate may contribute sodium and sulfate species;
Sodium chloride contributes sodium and chloride species;
Potassium chloride contributes potassium and chloride species;
Ascorbic acid and sodium ascorbate contribute additional dissolved species depending on the calculation methodology and pH.

The claim uses “calculated” rather than a measured osmolality value. That distinction matters. An accused product may argue that:

The calculation must use a particular dissociation model;
The claimed value cannot be established from measured osmolality alone;
The calculation must account for pH-dependent ionization;
The claimed “individual dissolved species” are not equivalent to osmoles measured by an osmometer.

Claims 2 and 22 narrow the dissolved-species range to 330-550 mmol/L. This narrower range provides a fallback position but reduces the number of potentially covered formulations.

Which claims cover sachets and two-dose administration?

Claims 6-8 and 13-15 address packaging and dosing.

Claims	Packaging limitation
6	Two first containers and two second containers
7	The containers of claim 6 are sachets
8	The first and second containers are sachets
13	Two first containers and two second containers
14	The containers are sachets
15	The first and second containers are sachets
18-20	Corresponding limitations for the exact flavored formulation

These claims are narrower than the core formulation claims. A product sold in one first container and one second container may avoid the two-container claims while remaining exposed under claims 1, 8, 10, 15, 17, 20 or the solution claims, depending on the actual packaging and formulation.

The packaging limitations create a potential design-around route. A manufacturer could seek to use a single combined sachet or a different container system. That strategy would not avoid the composition claims if the composition itself remains within the claimed ranges.

What formulations are protected by U.S. Patent 7,658,914?

The claims protect three formulation levels.

Broad PEG-ascorbate formulation

Claims 1 and 21 cover a broad formulation using:

90-125 g PEG;
5-10 g sulfate;
2-4 g sodium chloride;
0.5-1.3 g potassium chloride;
5-15 g ascorbate component; and
the specified dissolved-species range.

Exact MoviPrep-type formulation

Claims 9, 10 and 26-27 cover the formulation containing:

100 g PEG 3350;
7.5 g sodium sulfate;
2.691 g sodium chloride;
1.015 g potassium chloride;
4.7 g ascorbic acid; and
5.9 g sodium ascorbate.

Flavored and sweetened formulation

Claims 16-20 and 30-31 cover the addition of:

Aspartame;
Acesulfame K; and
Lemon flavor.

The “consisting of” language in claim 30 is particularly restrictive. It requires the aqueous solution to consist of water and the listed active, electrolyte, sweetener and flavor components.

How do the kit claims compare with the aqueous-solution claims?

Issue	Kit claims	Solution claims
Claims	1-20	21-31
Point of infringement	Dry compositions and containers	Reconstituted aqueous product
Packaging required	Yes for kit claims	No
Water required	No	Yes
Exact formulation coverage	Claims 9, 10, 17	Claims 26, 27, 30
Flavoring and sweetener	Claims 3-5, 11-12, 16-20	Claims 23-25, 28-31
Commercial relevance	Product packaging and sale	Dispensing, preparation or use of solution

The dual claim strategy increases enforcement coverage. A manufacturer may avoid a kit claim by changing packaging but still face a solution claim. Conversely, a packaged dry product may be exposed even before reconstitution.

The solution claims may raise divided-infringement issues if one entity manufactures the dry product, another distributes it and the end user adds water. Those issues depend on the accused conduct and the applicable infringement theory.

When does U.S. Patent 7,658,914 lose exclusivity?

The projected expiration date is December 22, 2025, based on a 20-year term measured from the relevant nonprovisional filing date of December 22, 2005.[2] The earliest priority date is identified as December 22, 2004.

Event	Date
Earliest identified priority date	December 22, 2004
U.S. nonprovisional filing	December 22, 2005
Patent issued	February 9, 2010
Projected ordinary expiration	December 22, 2025
Patent term adjustment	Must be verified from the issued patent record
Patent term extension	No extension is assumed in the ordinary expiration calculation

Patent term adjustment, terminal disclaimers and any patent-term extension can alter the effective expiration date. The operative date is the term shown in the USPTO patent record and, for an FDA-listed product, the current Orange Book entry.

The patent is not a biologic patent and does not create biosimilar exclusivity. A competing product would proceed through the ANDA or other applicable small-molecule pathway, not the biosimilar pathway.

What is the Orange Book status of the patent?

U.S. Patent 7,658,914 was associated with the MoviPrep NDA, including NDA 021881, for PEG 3350, sodium chloride, sodium sulfate, potassium chloride, ascorbic acid and sodium ascorbate for oral solution.[1,3]

The relevant regulatory distinction is:

The patent protects formulation and packaging features;
FDA approval is granted to the drug product under the NDA;
An ANDA applicant must address listed patents through certification or a statement permitted by the Food, Drug, and Cosmetic Act;
A Paragraph IV certification alleges that the listed patent is invalid, unenforceable or not infringed.

The Orange Book listing does not itself establish patent validity or infringement. It identifies the patent information submitted by the NDA holder and creates the statutory framework for ANDA patent certification.

Which companies are challenging the patent?

Publicly available records associate the MoviPrep patent estate with generic-ANDA activity by companies seeking approval for PEG 3350/electrolyte/ascorbate bowel-preparation products. The principal commercial participants have included the branded sponsor and generic applicants pursuing an ANDA for a MoviPrep-equivalent product.

The patent record supplied here does not establish a complete, current list of Paragraph IV filers, litigation dockets or settlement terms. A complete company-by-company challenge table cannot be stated accurately from the claim text alone.

What generic entry risks exist?

Generic entry risk is high for products that copy the exact formulation. The most exposed product profile is:

PEG 3350 at 100 g;
Sodium sulfate at 7.5 g;
Sodium chloride at 2.691 g;
Potassium chloride at 1.015 g;
Ascorbic acid at 4.7 g;
Sodium ascorbate at 5.9 g;
Separate dry compositions;
Sachet packaging; and
Lemon flavor with aspartame and acesulfame K.

A generic applicant could pursue several design-around positions:

Change the PEG amount outside 90-125 g;
Alter the sulfate concentration;
Replace or change the ascorbate salt;
Modify the ascorbic acid-to-salt ratio;
Use a different sodium chloride or potassium chloride concentration;
Change the packaging configuration;
Use a different flavoring or sweetener system; or
Develop a different bowel-cleansing formulation entirely.

The first five strategies risk loss of therapeutic equivalence, tolerability or commercial comparability. The packaging and flavoring strategies are easier to implement but do not necessarily avoid the composition claims.

How strong is the patent estate?

The patent has moderate-to-strong coverage for the disclosed product and weaker coverage against materially redesigned formulations.

Strengths

Exact formulation claims create clear coverage for the commercial product.
Broad ranges cover many near-copy formulations.
Both dry-kit and aqueous-solution claims are present.
The ascorbic acid/ascorbate ratio limits simple substitution strategies.
Packaging claims address the two-sachet administration format.
Dependent claims provide narrower positions if broad claims are challenged.

Weaknesses

The patent is composition-specific and does not cover all PEG bowel preparations.
Numerical limits create potential noninfringement positions.
The dissolved-species calculation may generate claim-construction disputes.
Exact-dose claims may be vulnerable to formulation changes.
The ordinary patent term is nearing or reaching expiration.
The patent does not create a biosimilar barrier or broad method-of-use exclusivity.

The estate is strongest against a generic that reproduces the commercial formulation. It is less effective against GoLYTELY-type high-volume PEG-electrolyte products, sulfate-only preparations such as Suprep, or materially different low-volume products such as Plenvu or Clenpiq.

How does this patent compare with competing bowel-preparation products?

Product category	Representative product	Main formulation concept	Exposure to U.S. 7,658,914
PEG-ascorbate low-volume	MoviPrep	PEG 3350 plus sulfate, chloride and ascorbate	High if formulation is copied
PEG-electrolyte high-volume	GoLYTELY, NuLYTELY	Large-volume PEG-electrolyte solution	Generally low
Sulfate-based low-volume	Suprep	Sodium sulfate, potassium sulfate and magnesium sulfate	Generally low
PEG-ascorbate newer formulation	Plenvu	Lower-volume PEG and ascorbate-based regimen	Requires element-by-element analysis
Picosulfate-based	Clenpiq, Prepopik	Sodium picosulfate, magnesium oxide and citric acid	Generally low

The patent does not monopolize the bowel-preparation market. Its commercial relevance depends on the continued use of the specific PEG-ascorbate architecture.

What licensing and settlement issues affect the patent?

The patent’s commercial history is tied to licensing and commercialization of the MoviPrep product between the underlying formulation owner and U.S. commercial partners. Product commercialization involved Norgine-related rights and Salix Pharmaceuticals’ U.S. marketing activities.[1]

A settlement with an ANDA applicant could establish an authorized generic launch date, a license date, a supply arrangement or a covenant not to sue. Those terms can materially affect practical exclusivity even when the patent remains unexpired. No settlement terms should be inferred solely from the patent claims or FDA label.

What is the likely generic launch scenario?

The practical launch scenarios are:

Scenario	Commercial result
No Paragraph IV litigation	FDA approval may support launch after statutory patent certification requirements are satisfied
Paragraph IV litigation with timely suit	30-month stay may delay approval or commercial launch
Settlement with licensed entry	Entry occurs on an agreed date, potentially before patent expiration
Formulation design-around	Applicant avoids some claims but may lose direct substitutability
Patent expiration	Claims cease to block otherwise lawful manufacture and sale, subject to other relevant patents

The expiration of this patent does not eliminate other possible barriers. Separate patents may cover formulations, dosing regimens, manufacturing processes, packaging, trademarks or newer products. A freedom-to-operate analysis must therefore examine the full family and adjacent patent estates.

What manufacturing and IP barriers remain after patent expiration?

The formulation itself is relatively straightforward to manufacture, but commercial barriers remain:

Control of PEG molecular-weight distribution;
Uniform blending of low-dose electrolytes and sweeteners;
Stability of ascorbic acid and sodium ascorbate;
Moisture protection for sachets;
Flavor masking;
Accurate fill weights;
Dissolution performance;
Bioequivalence and product-quality requirements;
FDA labeling and ANDA requirements; and
Trademark substitution and pharmacy-channel access.

These are practical barriers rather than permanent exclusivity rights. They can delay entry but do not extend the patent term.

What is the revenue exposure?

MoviPrep revenue exposure is concentrated in the branded product and authorized-generic channel. Public financial disclosures from Salix and its successor companies historically reported product-level revenue, but the claim text does not provide a current revenue figure. Revenue erosion after generic entry would depend on:

The timing of Paragraph IV entry;
Number of approved ANDAs;
Pharmacy substitution;
Reimbursement contracts;
Authorized-generic strategy;
Market share of Suprep, Plenvu, Clenpiq and other bowel preparations; and
Whether the branded product retains a clinical or formulary advantage.

The patent’s remaining value is therefore primarily launch-timing value, not long-duration market exclusivity.

Key Takeaways

U.S. Patent 7,658,914 covers a PEG 3350, sulfate, chloride and ascorbate bowel-cleansing formulation.
Claim 1 is the principal broad combination claim, while claims 10 and 17 target exact MoviPrep-type compositions.
The patent covers both dry kits and aqueous solutions.
Separate containers and sachet packaging are claimed, but packaging changes alone may not avoid the composition claims.
The ordinary projected expiration date is December 22, 2025, subject to verified patent-term adjustment or extension.
The patent is strongest against exact or near-exact PEG-ascorbate copies.
It does not cover all PEG bowel preparations and does not create biosimilar exclusivity.
Generic risk depends on the full Orange Book record, Paragraph IV certifications, litigation and any settlement-based launch date.

FAQs About U.S. Patent 7,658,914

Does U.S. Patent 7,658,914 cover GoLYTELY?

Generally, no. GoLYTELY-type products use a different PEG-electrolyte formulation and do not ordinarily satisfy the patent’s ascorbic acid and ascorbate requirements.

Does changing sodium ascorbate to another ascorbate salt avoid infringement?

Not necessarily. Claim 1 covers an ascorbate component containing ascorbic acid and a salt thereof. The replacement salt must be evaluated against the claim language, concentration, ratio and dissolved-species limitations.

Is the patent limited to MoviPrep sachets?

No. The broad claims cover formulation characteristics. Sachet-specific claims are narrower dependencies and do not define the entire patent scope.

Can a product avoid the patent by using one combined sachet?

A combined sachet may avoid claims requiring separate first and second containers, but it may remain exposed to aqueous-solution claims or other composition claims.

Does patent expiration automatically permit FDA generic substitution?

No. Patent expiration removes the patent barrier, but FDA approval, labeling, manufacturing compliance, regulatory exclusivity, trademarks and any other unexpired patents still affect launch and substitution.

References

U.S. Food and Drug Administration. (2023). MOVIPREP prescribing information. FDA.
United States Patent and Trademark Office. (2010). U.S. Patent No. 7,658,914, bowel cleansing compositions.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
United Kingdom	0224909.2	Oct 25, 2002

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	404223	⤷ Start Trial
Australia	2003274377	⤷ Start Trial
Australia	2008100865	⤷ Start Trial
Australia	2009227838	⤷ Start Trial
Canada	2502103	⤷ Start Trial
Canada	2672427	⤷ Start Trial
China	101897721	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Summary for Patent: 7,658,914