List of Excipients in Branded Drug BLUDIGO

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Sagent Pharmaceuticals	BLUDIGO	indigotindisulfonate sodium	25021-840	CITRIC ACID MONOHYDRATE	2037-12-23
Sagent Pharmaceuticals	BLUDIGO	indigotindisulfonate sodium	25021-840	SODIUM CITRATE	2037-12-23
Provepharm Inc	BLUDIGO	indigotindisulfonate sodium	81284-315	CITRIC ACID MONOHYDRATE	2037-12-23
Provepharm Inc	BLUDIGO	indigotindisulfonate sodium	81284-315	SODIUM CITRATE	2037-12-23

BLUDIGO Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: August 3, 2026

BLUDIGO is an 8 mg/mL sterile injection of indigotindisulfonate sodium used for intraoperative visualization of the ureters. Its formulation is commercially simple: the product uses sodium chloride and water for injection, with pH adjustment as needed. The main commercial opportunities are generic sterile injectable supply, ready-to-use operating-room formats, international registrations, and differentiated packaging rather than complex excipient innovation. The principal barriers are sterile manufacturing, validated color performance, supply reliability, and clinical workflow adoption.

What is BLUDIGO and how is it regulated?

BLUDIGO contains indigotindisulfonate sodium, also known as indigo carmine. The FDA-approved indication is visualization of the ureters during surgery in adults. The product is administered intravenously before or during the procedure, allowing the ureteral efflux to be visually identified.

Attribute	BLUDIGO profile
Brand	BLUDIGO
Active ingredient	Indigotindisulfonate sodium
Dosage form	Sterile injectable solution
Strength	8 mg/mL
Route	Intravenous
Primary use	Intraoperative ureter visualization
Product type	Small-molecule diagnostic surgical dye
Biologic status	Not a biologic
FDA pathway	New drug application
Commercial setting	Hospitals, ambulatory surgery centers, urologic and gynecologic surgery

The product is distinct from methylene blue, indocyanine green and radiographic contrast agents. Its value is visual identification of ureteral flow during surgery, not tissue perfusion imaging or fluoroscopic contrast enhancement.

FDA labeling identifies BLUDIGO as a single-dose sterile injectable product and describes the active ingredient, strength, dosing, warnings and storage requirements (U.S. Food and Drug Administration [FDA], 2022).

What excipients are used in BLUDIGO?

The publicly available prescribing information identifies a simple aqueous formulation consisting of indigotindisulfonate sodium, sodium chloride and water for injection. The product is pH-adjusted during manufacture where necessary. The exact manufacturing sequence, processing controls and container-closure specifications are not disclosed in the commercial label.

Formulation component	Function	Commercial significance
Indigotindisulfonate sodium	Diagnostic colorant and active ingredient	Controls visual intensity and clinical performance
Sodium chloride	Tonicity adjustment	Supports injectable tolerability and osmolality control
Water for injection	Sterile vehicle	Standard parenteral solvent
pH adjustment agents	Product stability and compatibility control	May affect color, degradation and container compatibility

The formulation does not rely on preservatives, surfactants, complex solubilizers, lipids or polymeric delivery systems. That reduces excipient complexity but leaves limited room for formulation-based differentiation.

The commercial formulation strategy should prioritize:

1. Chemical and color stability across the labeled shelf life.
2. Control of visible and subvisible particulates.
3. Sterility assurance and endotoxin control.
4. Low extractables and leachables from the vial and stopper.
5. Protection from light if stability studies show photodegradation.
6. Consistent visual performance after dilution or administration through hospital tubing.
7. Compatibility with common operating-room storage and handling conditions.

The principal formulation risk is not excipient toxicity. It is maintaining a reproducible dye concentration, color profile and injectable quality after sterilization, filling, transport and storage.

What excipient strategies could improve BLUDIGO?

Ready-to-use sterile vial strategy

The most defensible strategy is a simple, preservative-free, ready-to-use vial. Hospitals generally value products that eliminate bedside compounding and reduce medication-preparation steps. A single-dose vial can support predictable dosing and reduce contamination risk.

Potential commercial improvements include:

• Smaller vial sizes aligned with the recommended dose.
• Unit-dose packaging for operating-room carts.
• Clear labeling of concentration and total dye content.
• Barcoding compatible with hospital medication systems.
• Tamper-evident packaging.
• Light-protective secondary packaging where justified by stability data.

Prefilled syringe opportunity

A prefilled syringe could reduce preparation time and improve dosing consistency. It would require a container-closure system with demonstrated compatibility with indigotindisulfonate sodium, acceptable visibility of the solution and validated sterility through shelf life.

The business case is strongest where operating rooms prefer immediate availability and where the vial format creates waste. The regulatory burden would be higher because the syringe system becomes part of the product's critical quality profile.

Dilution and admixture compatibility

A differentiated product could provide validated instructions for compatibility with commonly used intravenous fluids. That opportunity depends on evidence. Unvalidated dilution claims would create regulatory and liability risk.

A manufacturer could develop stability data for:

• Normal saline.
• Common infusion tubing materials.
• Standard intravenous administration sets.
• Short-term operating-room use after withdrawal from the vial.

These data would have commercial value even if they do not create patent protection.

Alternative excipient systems

Alternative buffers, tonicity agents or stabilizers may improve stability, but the opportunity is limited. A materially different formulation would need to preserve the same clinical visualization profile and satisfy injectable-product requirements. A formulation containing additional excipients could create new risks involving hypersensitivity, incompatibility, osmolality and extractables.

For this product, the preferred strategy is excipient minimization rather than excipient expansion.

What patents protect BLUDIGO?

BLUDIGO's commercial protection should be separated into four categories:

1. Regulatory exclusivity.
2. Orange Book-listed patents.
3. Formulation or manufacturing patents.
4. Trade secrets and know-how.

The FDA prescribing information does not identify a patent number. A simple aqueous composition also offers a relatively narrow formulation-patent opportunity unless the sponsor has claimed a specific stability profile, manufacturing process, container system, dosing method or surgical use.

Potential claim categories include:

• Use of indigotindisulfonate sodium for intraoperative ureter visualization.
• Defined intravenous dosing regimens.
• Specific concentrations or administration volumes.
• Stabilized sterile solutions.
• Light-protective packaging.
• Container-closure systems.
• Manufacturing processes that preserve color strength or reduce impurities.

A patent covering a method of use may be more commercially relevant than a broad excipient patent. A competitor could attempt to market an equivalent product for the same surgical visualization purpose, making method-of-use claims relevant to labeling and Paragraph IV litigation.

The Orange Book, rather than the label alone, controls the current listing of patents and regulatory exclusivity for an approved NDA product (FDA, n.d.-a). Patent expiry dates should be calculated from the relevant patent's filing and adjustment history, not from the BLUDIGO approval date.

When does BLUDIGO lose exclusivity?

BLUDIGO does not have biologic exclusivity, biosimilar exclusivity or a biosimilar pathway. Any competition would generally arise through an ANDA, a 505(b)(2) application, or a full NDA, depending on the proposed product and the reference product's regulatory status.

The relevant timing mechanisms are:

Protection mechanism	Relevance to BLUDIGO
New chemical entity exclusivity	Unlikely to be the primary protection because indigotindisulfonate sodium has historical medical use
Three-year exclusivity	Could apply if the approval relied on sponsor-funded clinical investigations supporting a new indication, dosage form or use
Five-year NCE exclusivity	Not the expected basis for protection for this established active ingredient
Orphan exclusivity	Not apparent from the product's general surgical indication
Patent protection	Depends on current Orange Book listings and privately held or unlisted process and use patents
Data exclusivity outside the U.S.	Depends on jurisdiction and regulatory classification

The practical loss-of-exclusivity date is therefore the earliest date on which a legally permissible competing application can obtain approval, subject to listed patents, exclusivity and litigation outcomes. The FDA's Orange Book and Drugs@FDA records should be used for the operative status (FDA, n.d.-a; FDA, n.d.-b).

What Paragraph IV challenges and litigation risks exist?

A generic applicant could file a Paragraph IV certification against an Orange Book-listed patent, asserting that the patent is invalid, unenforceable or not infringed. The risk is highest for claims covering:

• The approved ureter-visualization indication.
• A specific concentration or dosing regimen.
• The sterile solution composition.
• A container or packaging configuration.
• Manufacturing controls that are difficult to design around.

For a simple injectable dye, litigation may focus less on complex composition claims and more on method-of-use claims and regulatory labeling. A generic applicant could seek a skinny label excluding a patented surgical use, although the commercial value of that strategy would depend on whether the excluded use represents most of the market.

No major publicly documented BLUDIGO patent settlement or launch-blocking litigation is established in the supplied record. A current litigation review should include federal district court dockets, the Federal Circuit, FDA Orange Book updates and Paragraph IV notices.

What generic entry risks exist for BLUDIGO?

Generic entry risk is moderate to high over the long term because:

• The active ingredient is a small molecule.
• The dosage form is an aqueous injectable solution.
• The excipient profile is uncomplicated.
• The product does not require a device-dependent delivery system.
• Clinical use is concentrated in institutional settings.
• Manufacturing can be replicated by qualified sterile injectable producers.

The main entry barriers are operational:

• Sterile fill-finish capacity.
• Dye raw-material quality and supply.
• Analytical methods for identity, assay, impurities and color.
• Container-closure compatibility.
• Stability under light and temperature stress.
• Hospital purchasing contracts.
• Reliable availability during surgical scheduling.

A generic may not need to match every commercial presentation if it demonstrates pharmaceutical equivalence and bioequivalence or satisfies the applicable regulatory standard. For injectable solutions, sameness of active ingredient, concentration, dosage form and route can simplify development, although product-specific FDA requirements remain controlling (FDA, 2019).

What commercial opportunities exist for manufacturers?

U.S. generic supply

The clearest opportunity is an ANDA or 505(b)(2) product with dependable supply and competitive hospital pricing. A manufacturer with existing sterile injectable capacity could obtain cost advantages over a new entrant.

Contract manufacturing

BLUDIGO creates a niche opportunity for contract development and manufacturing organizations with:

• Small-volume sterile liquid capabilities.
• High-potency or colorant handling controls.
• Short-run vial filling.
• Validated visual inspection.
• Hospital unit-dose packaging.

International expansion

The product could be positioned for registrations in markets where intraoperative ureter identification is accepted as a surgical use. Geographic opportunities depend on local classification of indigotindisulfonate sodium as a drug, diagnostic agent or surgical visualization product.

Potential markets include jurisdictions with established laparoscopic, gynecologic, colorectal and urologic surgery volumes. Local value depends on reimbursement, hospital procurement and whether surgeons already use methylene blue or other dyes.

OR workflow products

Commercial differentiation could include:

• Unit-dose packs.
• Prefilled syringes.
• Procedure-specific kits.
• QR-linked preparation and administration instructions.
• Integration with hospital inventory systems.
• Supply agreements with surgical distributors.

These opportunities are more likely to produce durable commercial value than a new excipient composition.

How does BLUDIGO compare with competing visualization agents?

Product or agent	Primary role	Formulation complexity	Main competitive issue
BLUDIGO	Ureter visualization during surgery	Low	Price, availability and workflow convenience
Methylene blue	Tissue, tract and urinary visualization in selected uses	Low to moderate	Familiarity and broader historical use
Indocyanine green	Near-infrared fluorescence imaging	Moderate	Requires compatible imaging equipment
Radiographic contrast agents	Fluoroscopic or radiographic visualization	Moderate	Requires imaging infrastructure and different procedural workflow

BLUDIGO's advantage is direct visual recognition without specialized fluorescence equipment. Its limitation is that it may be less differentiated where surgeons already use established dyes or where fluorescence imaging is available.

What is the revenue exposure and market outlook?

Revenue exposure is concentrated in hospital and ambulatory surgical procurement rather than chronic pharmacy dispensing. Demand depends on:

• Number of eligible surgical procedures.
• Adoption by gynecologic, colorectal and urologic surgeons.
• Product availability on hospital formularies.
• Relative pricing against methylene blue and other alternatives.
• Generic entry timing.
• Supply interruptions affecting operating-room confidence.

The product's small formulation footprint can support attractive manufacturing economics, but total revenue potential is limited by the narrow indication and procedure-linked demand. A supplier with broad hospital distribution and sterile injectable capacity may capture more value than a company relying solely on patent exclusivity.

Key Takeaways

• BLUDIGO is a sterile 8 mg/mL indigotindisulfonate sodium injection for intraoperative ureter visualization.
• Its public formulation uses sodium chloride and water for injection, with pH adjustment as needed.
• Excipient innovation is less attractive than packaging, stability, compatibility and workflow improvements.
• The most practical product extensions are prefilled syringes, unit-dose packaging and validated administration compatibility.
• Generic competition is structurally feasible because the product is a simple aqueous small-molecule injection.
• Patent value is more likely to arise from method-of-use, stability, manufacturing or packaging claims than from a broad excipient platform.
• BLUDIGO has no biosimilar pathway because it is not a biologic.
• Commercial value depends heavily on sterile supply reliability, hospital contracting and operating-room adoption.
• The current Orange Book record and FDA exclusivity data control the operative patent and launch analysis.

FAQs

Is BLUDIGO a contrast agent?

No. BLUDIGO is a surgical visualization dye used to identify the ureters. It is not a radiographic contrast agent and does not require fluoroscopy for its primary use.

Can BLUDIGO be reformulated with preservatives?

A preservative-containing version would require a new product-development and regulatory assessment. The current sterile single-dose strategy avoids preservative exposure and is more consistent with operating-room injectable use.

Is a prefilled BLUDIGO syringe commercially attractive?

Yes. A prefilled syringe could reduce preparation steps and product waste. Its value would depend on syringe compatibility, shelf-life performance, sterility validation and hospital purchasing preferences.

Could a generic launch BLUDIGO with a different excipient system?

Potentially, subject to FDA requirements for pharmaceutical equivalence, product quality and the applicable abbreviated or hybrid regulatory pathway. A different excipient system could create comparability and stability issues.

Does BLUDIGO have biosimilar competition?

No. Biosimilar competition applies to biological products. BLUDIGO contains the small-molecule active ingredient indigotindisulfonate sodium.

References

1. U.S. Food and Drug Administration. (2022). BLUDIGO (indigotindisulfonate sodium) injection, prescribing information. FDA.

2. U.S. Food and Drug Administration. (2019). ANDAs for certain highly purified synthetic peptides of rDNA origin: Guidance for industry. FDA.

3. U.S. Food and Drug Administration. (n.d.-a). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

4. U.S. Food and Drug Administration. (n.d.-b). Drugs@FDA: FDA-approved drugs. FDA.

5. U.S. Food and Drug Administration. (n.d.-c). Inactive Ingredient Database. FDA.