United States Patent 10,130,646: Calcium Gluconate Injection Claims, Patent Scope, and Generic Entry Risk

U.S. Patent No. 10,130,646 covers a terminally sterilized calcium gluconate solution in a flexible plastic bag. The core combination requires calcium gluconate, calcium saccharate, sodium chloride, water, a pH of 6 to 8.2, and specified concentration ranges. Dependent claim 2 narrows the formulation to a specific premixed injectable composition, while claim 3 adds a 24-month shelf-life limitation at 25°C.[1]

The patent is formulation- and container-specific. It does not broadly cover every calcium gluconate injection, vial presentation, oral calcium product, or manufacturing process. A competing product would face infringement risk only if it satisfies every limitation of an asserted claim, either literally or under the doctrine of equivalents.

What does U.S. Patent 10,130,646 claim?

What is the scope of independent claim 1?

Claim 1 requires the following elements:

Claim element	Required limitation
Dosage form	A terminally sterilized aqueous solution
Active ingredient	Calcium gluconate at 1 to 15 wt.%
Stabilizer or additive	Calcium saccharate at 1 to 19 wt. parts per 100 wt. parts calcium gluconate
Electrolyte	Sodium chloride
Solvent	Water as the remainder
Container	A flexible plastic container
Container form	The flexible container must be a bag
pH	6.0 to 8.2

The claim is a closed combination in practical infringement analysis. A product with calcium gluconate and sodium chloride but no calcium saccharate would not literally meet claim 1. A product in a vial would not literally meet the express bag limitation. A formulation outside the calcium gluconate, calcium saccharate, or pH ranges would also fall outside the literal language.

The phrase "terminally sterilized" focuses on sterilization of the filled and sealed container, rather than aseptic manufacture alone. The claim therefore ties the formulation to a finished injectable product subjected to a sterilization process after packaging.

What formulation does claim 2 protect?

Claim 2 narrows claim 1 to a formulation containing approximately:

Component	Claimed amount
Calcium gluconate monohydrate	19.6 mg/mL
Calcium D-saccharate	About 0.9 mg/mL
Sodium chloride	About 6.75 mg/mL

The calcium gluconate concentration is approximately 1.96 wt.% assuming an aqueous density near 1 g/mL. The calcium saccharate concentration is approximately 0.09 wt.%, and sodium chloride is approximately 0.675 wt.%.

The composition corresponds to a premixed calcium gluconate-in-saline presentation rather than a conventional concentrated calcium gluconate vial. Claim 2 still incorporates every limitation of claim 1. It therefore requires the bag, terminal sterilization, pH range, and calcium saccharate-to-calcium gluconate relationship in addition to the listed concentrations.

What does claim 3 add?

Claim 3 requires the claim 2 formulation to have a shelf life of at least about 24 months when stored at 25°C.

This limitation is commercially significant because it links patent coverage to product stability. A product may contain the claimed formulation but avoid claim 3 if the patent owner cannot establish the claimed shelf-life characteristic. Claim 3 does not eliminate claim 1 or claim 2 risk, because a product can infringe those claims without satisfying the 24-month shelf-life limitation.

How strong is the patent estate for calcium gluconate bags?

The disclosed claims indicate a focused estate rather than a broad calcium gluconate platform. The strongest protection is concentrated in the intersection of four features:

Calcium gluconate in a relatively dilute aqueous formulation.
Calcium saccharate as a defined formulation component.
Terminal sterilization in a flexible plastic bag.
A controlled pH range and, for claim 3, long-term stability.

A competitor that changes only one nonessential excipient may remain within claim 1. A competitor that removes calcium saccharate, uses a vial, or adopts a materially different calcium gluconate concentration may have a stronger noninfringement position.

Which limitations create the main design-around opportunities?

Design-around strategy	Likely effect on claim 1
Use a glass vial	Avoids the express flexible plastic bag limitation
Omit calcium saccharate	Avoids the express calcium saccharate limitation
Use a different stabilizer	May avoid literal infringement, subject to equivalents analysis
Use calcium gluconate outside 1 to 15 wt.%	Avoids the concentration range if outside its legal scope
Use pH below 6 or above 8.2	Avoids literal pH infringement
Manufacture aseptically without terminal sterilization	May avoid the sterilization limitation
Use a prefilled syringe or bottle	Avoids the bag limitation
Use a different salt concentration	Does not necessarily avoid claim 1, because claim 1 requires sodium chloride but does not specify its concentration

Changing sodium chloride concentration alone is unlikely to provide a complete design-around because claim 1 does not impose a numerical sodium chloride range. The more important limitations are calcium saccharate, the bag presentation, terminal sterilization, pH, and calcium gluconate concentration.

What patent expiration date applies to U.S. Patent 10,130,646?

U.S. Patent 10,130,646 was issued on November 20, 2018.[1] Its enforceable term is generally governed by the 20-year term measured from the earliest effective U.S. nonprovisional filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and any applicable prosecution history.[2][3]

The issue date alone does not establish the expiration date. A definitive expiration analysis must use the patent’s earliest effective nonprovisional filing date and the USPTO term-adjustment record. Patent-term extension under 35 U.S.C. § 156 is generally associated with qualifying regulatory review and is more common for certain drug patents than for formulation patents covering abbreviated-application products.[2]

There is no basis in the supplied claims alone to assign a precise expiration date, patent-term adjustment period, terminal disclaimer, or regulatory patent-term extension.

Is U.S. Patent 10,130,646 listed in the Orange Book?

The patent number alone does not establish Orange Book listing status. The FDA Orange Book lists patents submitted by NDA holders for approved drug products, including patents covering drug substances, drug products, and approved methods of use under applicable FDA listing rules.[4]

A formulation patent covering a calcium gluconate bag may be listed if it is associated with an NDA product and satisfies FDA listing requirements. It may also remain outside the Orange Book if the relevant product was approved through an abbreviated pathway, a 505(b)(2) application, or another regulatory route that does not create an Orange Book listing for the patent.

Orange Book listing and enforceability are separate questions:

Listing can trigger a Paragraph IV certification and statutory notice process.
Failure to list does not automatically invalidate the patent.
A listed patent is not necessarily valid or infringed.
A patent may be asserted in litigation even if it is not listed in the Orange Book.

What Paragraph IV challenges could target this patent?

A generic applicant could address the patent through a Paragraph IV certification if the patent is listed against the relevant reference product and the applicant seeks approval before patent expiration.[5] The principal challenge theories would likely involve:

Anticipation

A challenger would seek prior art disclosing the full combination of:

calcium gluconate;
calcium saccharate;
sodium chloride;
the claimed concentration ranges;
pH of 6 to 8.2;
a terminally sterilized aqueous solution;
a flexible plastic bag.

A reference disclosing calcium gluconate injection alone would not anticipate claim 1 unless it also disclosed the saccharate, container, sterilization, concentration, and pH limitations.

Obviousness

Obviousness presents the more substantial risk for a narrow formulation claim. A challenger could combine prior art relating to:

calcium gluconate injection;
calcium saccharate as a stabilizer or impurity-control agent;
saline dilution;
flexible plastic infusion bags;
terminal sterilization;
pH adjustment;
long-term stability testing.

The patent owner would likely rely on the claimed combination, compatibility of the formulation with terminal sterilization, container performance, and stability results to rebut an obviousness challenge. Unexpected stability or reduced degradation can be important, but the commercial strength of that position depends on the patent specification and prosecution record, not on the claim text alone.[2]

Written description and enablement

Claim 1 covers broad concentration ranges and a broad class of flexible plastic bags. A challenger could examine whether the specification supports the full scope of the claimed ranges and container materials. Claim 3 could face a separate challenge if the specification does not adequately describe or enable the claimed 24-month shelf life across the full formulation scope.

What patent litigation affects U.S. Patent 10,130,646?

The supplied information identifies the patent and claims but does not establish a litigation docket, asserted claims, defendants, settlement terms, or Paragraph IV notice history. The existence of the patent should not be treated as evidence that litigation has occurred or that a generic applicant has challenged it.

For business analysis, the relevant litigation questions are:

Issue	Commercial consequence
Orange Book listing	Determines whether a listed-patent Paragraph IV pathway is available
NDA association	Identifies the product against which the patent may be listed
Claim construction	Determines the meaning of “terminally sterilized,” “bag,” “about,” and “shelf life”
Infringement evidence	Requires formulation, packaging, sterilization, pH, and stability data
Validity record	Includes prosecution amendments, examiner rejections, and cited prior art
Settlement terms	May delay generic entry or permit an authorized generic
Injunction or stay	Can affect FDA approval timing and launch timing

Are biosimilars relevant to this patent?

No. Calcium gluconate is a small-molecule active pharmaceutical ingredient, not a biologic subject to the biosimilar pathway under the Biologics Price Competition and Innovation Act. The relevant competitive pathways are abbreviated new drug applications, 505(b)(2) applications, contract-manufactured products, hospital-channel products, and reformulated injectable presentations.

A calcium gluconate generic applicant would generally address pharmaceutical equivalence, bioequivalence where applicable, sterility, container compatibility, extractables and leachables, particulate matter, endotoxins, and stability. The patent risk is primarily a formulation and packaging issue, not a biosimilar interchangeability issue.

How does this patent compare with conventional calcium gluconate products?

Product type	Likely relationship to the claimed combination
Calcium gluconate 10% injection in a glass vial	Usually outside the express bag limitation and likely outside the claimed concentration range
Calcium gluconate in saline in a flexible bag	Highest potential overlap
Calcium gluconate without calcium saccharate	Potential design-around, subject to equivalents
Calcium gluconate premix in a bottle	Likely outside the bag limitation
Oral calcium gluconate tablets or solutions	Outside the injectable bag and terminal-sterilization scope
Calcium chloride injection	Different active ingredient and outside the claims
Compounded calcium gluconate infusion	Risk depends on formulation, container, pH, sterilization, and commercial-use facts

The patent is most relevant to hospital-ready premixed calcium gluconate bags. It is less relevant to traditional concentrated vial products and noninjectable calcium products.

What manufacturing and intellectual-property barriers remain?

Even if a generic avoids the patent claims, injectable manufacture creates regulatory and operational barriers. The product must maintain sterility and chemical stability through terminal sterilization, storage, transport, and administration. Plastic-bag products also raise container-closure, compatibility, leachables, and extractables issues.

The claimed use of calcium saccharate may reflect a stability or degradation-control strategy. Removing it may avoid literal claim coverage but create a separate development problem. A substitute stabilizer may require new formulation work, comparative stability data, and regulatory justification.

Geographic protection is also separate by jurisdiction. U.S. Patent 10,130,646 provides rights only in the United States. Foreign family members, if any, would require separate review for filing dates, granted claims, maintenance status, and expiration. No foreign rights can be inferred from the U.S. patent number.

What generic launch scenarios exist?

Launch after patent expiry

This is the lowest litigation-risk path if no other unexpired patent or regulatory exclusivity blocks approval.

Paragraph IV launch

A generic applicant may challenge a listed patent before expiry. The patent owner could sue within the statutory period, potentially triggering a 30-month stay of FDA approval under the Hatch-Waxman framework.[5]

Carve-out or nonoverlapping product

A product in a vial, without calcium saccharate, or outside the claimed concentration range may seek approval with a noninfringing formulation. The commercial penalty is that the product may not match the protected premixed bag presentation.

505(b)(2) strategy

A sponsor developing a modified calcium gluconate presentation could use a 505(b)(2) pathway, depending on the product’s formulation, route, and reliance on an approved reference product. Patent certification and labeling issues would still require product-specific analysis.

Key Takeaways

Claim 1 covers a narrow but commercially relevant combination: terminally sterilized calcium gluconate solution in a flexible plastic bag.
Calcium saccharate is a mandatory limitation and creates an important design-around point.
Claim 2 targets a specific premixed calcium gluconate, calcium saccharate, and sodium chloride formulation.
Claim 3 adds at least approximately 24 months of shelf life at 25°C.
Conventional 10% calcium gluconate vials are materially different from the claimed product and may avoid literal infringement.
The patent is relevant to generic calcium gluconate bags, not biosimilars.
Orange Book listing, Paragraph IV exposure, litigation history, settlement restrictions, and expiration cannot be established from the claim text alone.
The principal validity risks are anticipation, obviousness, written description, enablement, and claim-construction disputes involving terminal sterilization, “about,” bag packaging, and shelf life.
Patent protection is U.S.-specific unless corresponding foreign family rights are separately confirmed.

FAQs About U.S. Patent 10,130,646

Does using calcium gluconate in a saline bag automatically infringe?

No. The product must satisfy all limitations of an asserted claim, including calcium saccharate, terminal sterilization, pH, concentration, and the flexible plastic bag requirement.

Can a generic avoid the patent by using a glass container?

A glass vial would not literally satisfy the flexible plastic bag limitation. The remaining claims and any doctrine-of-equivalents theory would still require separate analysis.

Is calcium saccharate required in claim 1?

Yes. Claim 1 expressly requires from 1 to 19 wt. parts of calcium saccharate per 100 wt. parts of calcium gluconate.

Does claim 3 require every product to have a 24-month expiration dating period?

Claim 3 requires the claimed formulation to have at least about 24 months of shelf life at 25°C. Claims 1 and 2 do not include that specific shelf-life limitation.

Is this patent relevant to calcium gluconate injection in a 10% vial?

It may be less relevant because a conventional 10% vial typically differs in concentration and container type. Infringement depends on the actual formulation, pH, sterilization method, and packaging.

References

U.S. Patent No. 10,130,646 B2, claims 1-3 (issued Nov. 20, 2018).
35 U.S.C. §§ 102, 103, 112, 154, 271, 282.
U.S. Patent and Trademark Office. (n.d.). Patent term adjustment. United States Department of Commerce.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
21 U.S.C. § 355(j); 35 U.S.C. § 271(e).

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Fresenius Kabi Usa	CALCIUM GLUCONATE IN SODIUM CHLORIDE	calcium gluconate	SOLUTION;INTRAVENOUS	208418-004	Jun 17, 2021		DISCN	Yes	No	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
Fresenius Kabi Usa	CALCIUM GLUCONATE IN SODIUM CHLORIDE	calcium gluconate	SOLUTION;INTRAVENOUS	208418-005	Jun 17, 2021		DISCN	Yes	No	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
Hq Spclt Pharma	CALCIUM GLUCONATE IN SODIUM CHLORIDE	calcium gluconate	SOLUTION;INTRAVENOUS	210906-001	Oct 29, 2018		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
Hq Spclt Pharma	CALCIUM GLUCONATE IN SODIUM CHLORIDE	calcium gluconate	SOLUTION;INTRAVENOUS	210906-003	Jun 4, 2021		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
Hq Spclt Pharma	CALCIUM GLUCONATE IN SODIUM CHLORIDE	calcium gluconate	SOLUTION;INTRAVENOUS	210906-002	Oct 29, 2018		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Details for Patent: 10,130,646

Which drugs does patent 10,130,646 protect, and when does it expire?

Summary for Patent: 10,130,646