List of Excipients in Branded Drug PLASBUMIN

PLASBUMIN Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: September 24, 2026

PLASBUMIN is a plasma-derived human albumin injectable marketed in 5% and 25% strengths. Its formulation uses sodium caprylate and N-acetyl-DL-tryptophanate as stabilizers, with sodium chloride contributing to tonicity and ionic strength. The strongest commercial opportunities are not conventional generic substitution. They are premium albumin presentations, improved container systems, low-volume high-concentration products, recombinant-albumin alternatives, and albumin-enabled biologic formulations. PLASBUMIN is regulated as a biologic, so patent and exclusivity analysis depends on the Biologics License Application and Purple Book framework rather than a conventional Orange Book listing.

What is PLASBUMIN and which excipients does it contain?

PLASBUMIN is a sterile solution of human albumin derived from pooled human plasma. Grifols markets PLASBUMIN-5 and PLASBUMIN-25 for intravenous use. The products contain approximately 5% or 25% albumin, respectively.

Product	Albumin concentration	Principal stabilizers	Other formulation components	Route
PLASBUMIN-5	5%	Sodium caprylate; N-acetyl-DL-tryptophanate	Sodium chloride; water for injection	Intravenous
PLASBUMIN-25	25%	Sodium caprylate; N-acetyl-DL-tryptophanate	Sodium chloride; water for injection	Intravenous

The FDA prescribing information identifies sodium caprylate and N-acetyl-DL-tryptophanate as stabilizing agents. The formulation is preservative-free and has a controlled pH range suitable for parenteral administration. Exact concentrations, fill volumes, package configurations, and labeling details should be controlled against the current product-specific FDA label because these parameters can vary by presentation and manufacturing site.[1]

Why are sodium caprylate and N-acetyl-DL-tryptophanate used?

Albumin is vulnerable to oxidation, aggregation, denaturation, and surface-related instability during purification, storage, transport, and administration. Fatty-acid binding is a natural property of albumin. Caprylate, an octanoate salt, binds albumin and helps preserve its conformation during processing and storage.

N-acetyl-DL-tryptophanate is used as a stabilizer in albumin products and can provide protection against thermal and oxidative stress. The combination has long-standing regulatory precedent in human albumin manufacturing. That precedent reduces formulation risk relative to an entirely new excipient system.

The commercial limitation is that these stabilizers are part of a mature formulation platform. A new entrant is unlikely to obtain strong protection merely by copying the same excipient combination. Differentiation must come from concentration, delivery, manufacturing, container closure, safety profile, or a new albumin-based use.

What formulation patents protect PLASBUMIN?

No current PLASBUMIN-specific composition patent is identified in the core FDA product materials. PLASBUMIN is a mature plasma-derived biologic, and its principal formulation components have been used across the human albumin field for decades. Any original formulation patents would generally be expected to have expired unless later patents cover a distinct process, package, concentration, or use.

The relevant intellectual-property categories are:

IP category	Relevance to PLASBUMIN	Commercial strength
Albumin and stabilizer composition	Covers defined albumin, caprylate, tryptophanate, pH, and ionic conditions	Low to moderate for a new entrant unless materially differentiated
Manufacturing process	Covers fractionation, purification, viral inactivation, filtration, and filling	Moderate to high
Low-aluminum processing	Covers controls that reduce aluminum exposure or leachables	Moderate
Container closure	Covers glass, polymer, stopper, bag, and adsorption-control systems	Moderate
High-concentration albumin	Covers concentrated solutions with defined viscosity, osmolality, and stability	Moderate
Recombinant albumin	Covers non-plasma sources and production systems	High where the claims are technically narrow and commercially relevant
Albumin conjugates and delivery systems	Covers albumin-bound drugs, fusion proteins, and half-life extension	High in selected therapeutic markets
Method of use	Covers albumin in specific fluid-resuscitation, nephrology, hepatic, or critical-care protocols	Variable and vulnerable to clinical-use restrictions

Patent strength depends more on claim scope and freedom to operate than on the age of the PLASBUMIN brand. A patent that claims only caprylate-stabilized albumin may face substantial prior-art pressure. A patent that claims a validated manufacturing sequence, defined impurity profile, or container system can be more defensible.

What is the Orange Book status of PLASBUMIN?

PLASBUMIN is not analyzed like a conventional small-molecule drug in the Orange Book. Human albumin is a biologic regulated under a BLA. The primary regulatory reference is the FDA Purple Book, together with the applicable BLA record and FDA biologics guidance.[2]

The practical consequences are material:

• A conventional ANDA pathway does not apply.
• A generic-drug Paragraph IV certification is not the standard challenge route.
• Biosimilar or interchangeable status would be assessed under section 351(k) of the Public Health Service Act.
• Patent disputes may proceed under the Biologics Price Competition and Innovation Act, including the statutory patent-exchange process.
• Product-specific exclusivity depends on the age and regulatory history of the reference biologic.

PLASBUMIN predates the modern 12-year reference-product exclusivity period. That statutory period therefore does not create a current commercial barrier equivalent to a recently approved biologic. The main barriers are manufacturing validation, donor-plasma access, viral-safety controls, clinical comparability, supply reliability, and hospital contracting.

When does PLASBUMIN lose exclusivity?

PLASBUMIN’s original market protection is effectively mature. The product has been commercially available for decades, and no current 12-year reference-biologic exclusivity period is expected to remain relevant to its original approval.

That does not mean market entry is easy. A competing human albumin product must establish:

1. Consistent source plasma and donor qualification.
2. Validated fractionation and purification.
3. Viral inactivation and removal.
4. Control of aggregates, polymers, immunoglobulin impurities, and process residues.
5. Sterility and container-closure integrity.
6. Stability across the labeled shelf life.
7. Regulatory comparability or independent approval support.
8. Reliable supply at hospital and wholesaler scale.

For a new biologic, patents may extend beyond regulatory exclusivity. For PLASBUMIN, the more important question is whether a competitor can reproduce the required quality profile at a cost that supports hospital purchasing and reimbursement.

Which companies are challenging PLASBUMIN or competing with it?

The competitive field includes branded human albumin products, plasma fractionators, recombinant albumin suppliers, and manufacturers of albumin-containing combination products.

Relevant competitors and adjacent suppliers include:

• CSL Behring, with Albuminex human albumin products.
• Grifols, with PLASBUMIN and other plasma-derived products.
• Kedrion, with Alburex and related human albumin products in selected markets.
• Octapharma, with human albumin products in international markets.
• Biotest and other regional plasma fractionators.
• Recombinant-albumin manufacturers supplying research, cell-culture, vaccine, and biologic-production markets.

A direct biosimilar competitor would face a more complex development path than a small-molecule generic. Plasma-derived products have source-material variability and manufacturing attributes that can be difficult to establish through analytical similarity alone. The FDA has not created a simple, automatic substitution pathway for human albumin analogous to pharmacy substitution for conventional generics.

What excipient strategy is best for a competing albumin product?

The most defensible strategy is a tiered approach rather than immediate substitution of the established stabilizers.

Tier 1: Retain the established stabilizer platform

Use sodium caprylate and N-acetyl-DL-tryptophanate where the objective is rapid regulatory alignment and low formulation risk. This approach benefits from extensive historical use and known albumin compatibility.

The commercial advantage is predictable development. The disadvantage is limited differentiation and weak composition-of-matter patent potential.

Tier 2: Optimize concentration and ionic environment

Potential improvements include:

• Reduced sodium load.
• Lower osmolality for selected patient populations.
• High-concentration albumin with manageable viscosity.
• Defined pH control.
• Lower particulate formation after dilution.
• Improved compatibility with infusion sets and co-administered solutions.

These changes require careful assessment because albumin conformation, ligand binding, viscosity, and aggregation can shift with pH, ionic strength, and concentration.

Tier 3: Develop a next-generation stabilizer system

Candidate approaches may include alternative fatty-acid salts, amino-acid stabilizers, polyols, antioxidants, or combinations designed to reduce oxidation and aggregation. The commercial benefit would be strongest if the system also delivers one of the following:

• Lower excipient burden.
• Better thermal stability.
• Improved post-opening stability.
• Lower risk of aluminum or extractables.
• Better compatibility with polymer containers.
• A patentable formulation window.

The principal risk is regulatory comparability. Changing the stabilizer system can affect albumin’s higher-order structure, ligand occupancy, oxidation state, aggregate content, and biological performance. A new excipient combination may require a more extensive comparability package than a simple manufacturing change.

Tier 4: Use albumin as a functional excipient

Albumin is also used as a formulation component in vaccines, viral vectors, enzymes, cell therapies, and other biologics. It can reduce adsorption to surfaces and protect proteins during freezing, drying, agitation, and dilution.

This creates a separate commercial opportunity for:

• Recombinant human albumin.
• Animal-origin-free albumin.
• Low-endotoxin albumin.
• Defined-grade albumin for cell and gene therapy.
• Albumin with controlled fatty-acid and oxidation profiles.
• Albumin designed for lyophilized biologic formulations.

This market can be more attractive than competing directly with PLASBUMIN in hospital albumin replacement because customers may pay for traceability, consistency, animal-origin-free status, and manufacturing compatibility.

What manufacturing and IP barriers affect commercial entry?

The largest barrier is not the excipient itself. It is the integrated manufacturing process.

Plasma-derived albumin barriers

A competitor needs access to qualified plasma at sufficient volume and must manage:

• Donor screening and testing.
• Pool traceability.
• Cold ethanol or equivalent fractionation.
• Chromatographic purification.
• Viral inactivation.
• Nanofiltration or other viral-removal controls.
• Removal of aggregates and impurities.
• Aseptic filling.
• Lot-release testing.

Plasma supply is a strategic asset. A formulation patent without secure plasma access has limited commercial value.

Recombinant albumin barriers

Recombinant albumin avoids donor-plasma dependence but introduces other challenges:

• Expression yield.
• Host-cell impurity control.
• Glycation and oxidation control.
• Higher-order structure.
• Scale-up economics.
• Demonstration of equivalence to plasma-derived albumin for the intended use.

Recombinant albumin is more attractive for excipient and bioprocessing markets than for immediate replacement of intravenous human albumin, where clinical, regulatory, and procurement expectations are established around plasma-derived products.

Container and delivery-system barriers

Packaging is an underdeveloped differentiation area. Patentable opportunities may include:

• Low-binding polymer bags.
• Improved stoppers with reduced leachables.
• Oxygen-reduced headspace.
• Light-protective packaging.
• Smaller-volume high-concentration presentations.
• Dual-chamber systems for controlled dilution.
• Device configurations that reduce foaming and surface exposure.

These products can create commercial value without altering the core albumin molecule.

What generic launch risks exist for PLASBUMIN?

A direct generic launch scenario is unlikely to resemble an ANDA launch. The leading risks are:

Risk	Effect on launch
Biologic comparability	May require extensive analytical and clinical support
Plasma supply	Can constrain volume and increase cost
Hospital tenders	Price competition may compress margins
Formulation similarity	Limits differentiation
Product shortages	Can create opportunity but require immediate capacity
Regulatory classification	Determines the applicable application pathway
Patent scope	Process and formulation patents may delay entry
Substitution rules	Hospitals may not automatically substitute products
Quality failures	A single recall can damage market access
Reimbursement	Albumin use may be protocol-dependent and budget-sensitive

The most credible entry model is a differentiated biologic or specialty presentation, not a pure price-based copy.

How does PLASBUMIN compare with recombinant albumin opportunities?

Attribute	PLASBUMIN-style plasma-derived albumin	Recombinant human albumin
Raw material	Human plasma	Engineered production cell or microbial system
Supply risk	Dependent on donor plasma	Dependent on bioprocess capacity
Regulatory history	Extensive clinical and manufacturing precedent	More limited for systemic replacement uses
Excipient opportunity	Incremental optimization	Broad platform and process opportunity
Patent potential	Mostly process, package, and use claims	Production, sequence, purification, and formulation claims
Primary market	Intravenous volume expansion and hypoalbuminemia-related uses	Bioprocessing, cell culture, vaccines, gene therapy, specialty formulations
Commercial differentiation	Concentration, safety, packaging, supply	Origin, consistency, animal-origin-free status, impurity profile

Recombinant albumin offers stronger long-term IP potential. PLASBUMIN-type products offer a more established clinical market but lower composition-based differentiation.

What licensing opportunities exist around PLASBUMIN excipients?

Licensing opportunities are more likely to arise around enabling technologies than around the legacy PLASBUMIN formulation itself.

Potential targets include:

1. Recombinant albumin production platforms.
2. Albumin stabilizer combinations with validated long-term stability.
3. Low-binding polymer containers.
4. Continuous or intensified plasma fractionation.
5. Viral-clearance technologies.
6. Albumin conjugation platforms for half-life extension.
7. Albumin-containing formulations for vaccines and cell therapies.
8. Analytical methods for oxidation, aggregation, and ligand occupancy.
9. Animal-origin-free excipient portfolios.
10. Small-volume high-concentration infusion systems.

A strong licensing package should include issued claims, freedom-to-operate analysis, scale-up data, extractables and leachables data, and a regulatory history. A patent that lacks manufacturing reproducibility or commercial-grade stability data has limited transaction value.

Key Takeaways

• PLASBUMIN is a mature plasma-derived human albumin biologic marketed in 5% and 25% strengths.
• Its formulation relies primarily on sodium caprylate and N-acetyl-DL-tryptophanate as stabilizers, with sodium chloride and water for injection.
• PLASBUMIN is not governed by the conventional small-molecule Orange Book framework.
• Original regulatory exclusivity is no longer the principal barrier to competition.
• The strongest barriers are plasma supply, viral safety, process validation, quality consistency, and hospital procurement.
• A copycat formulation has limited patent value.
• Stronger opportunities exist in recombinant albumin, animal-origin-free excipients, high-concentration presentations, container systems, and albumin-enabled biologic formulations.
• Formulation changes require close control of aggregation, oxidation, ligand binding, osmolality, viscosity, and container compatibility.
• Commercial success is more likely from a differentiated product or platform than from an unprotected PLASBUMIN substitute.

Frequently Asked Questions

Is PLASBUMIN a plasma-derived or recombinant product?

PLASBUMIN is a plasma-derived human albumin product manufactured from pooled human plasma. It is not a recombinant albumin product.[1]

Can sodium caprylate be replaced in an albumin formulation?

Yes, replacement is technically possible, but the change can affect albumin structure, oxidation, aggregation, stability, and regulatory comparability. A replacement strategy needs forced-degradation, accelerated-stability, structural, and clinical-relevance data.

Does PLASBUMIN have a 12-year biologic exclusivity period remaining?

No. PLASBUMIN has been marketed for decades, and the modern 12-year reference-biologic exclusivity period is not the principal barrier to entry for this mature product.

Is human albumin an excipient for biologics?

Yes. Human or recombinant albumin can function as a stabilizing and surface-protective excipient in selected biologics, vaccines, cell-culture systems, and other parenteral products.

What is the highest-value patent strategy for an albumin competitor?

The strongest strategy generally combines a manufacturing patent, a defined formulation or container claim, and a clinically relevant method-of-use claim. A claim limited to a long-established caprylate and tryptophanate combination is less likely to provide durable market exclusivity.

References

1. U.S. Food and Drug Administration. (n.d.). PLASBUMIN-5 and PLASBUMIN-25 prescribing information. Grifols Therapeutics LLC.

2. U.S. Food and Drug Administration. (n.d.). Purple Book: Lists of licensed biological products with reference product exclusivity and biosimilarity or interchangeability evaluations. https://purplebooksearch.fda.gov/

3. U.S. Food and Drug Administration. (2020). Questions and answers on biosimilar development and the BPCI Act: Guidance for industry. https://www.fda.gov/

4. United States Pharmacopeia. (2024). Human albumin monograph. In United States Pharmacopeia and National Formulary.

5. European Medicines Agency. (2018). Guideline on plasma-derived medicinal products. https://www.ema.europa.eu/