List of Excipients in Branded Drug PERSANTINE

PERSANTINE Excipient Strategy and Commercial Opportunities for Dipyridamole

Last updated: August 25, 2026

Persantine is the brand name for dipyridamole, an older antiplatelet and coronary vasodilator. Its core active-ingredient patents and regulatory exclusivities have expired, leaving limited value in the legacy immediate-release tablet. Commercial opportunity remains in differentiated dipyridamole products, particularly modified release, palatable oral liquids, low-dose pediatric formats, combination products, and injectable formulations with improved handling and stability.

What is the current FDA and commercial status of Persantine?

Persantine is no longer a meaningful exclusivity asset in the United States. Dipyridamole is available through generic products, while the branded product has limited commercial relevance compared with generic dipyridamole and dipyridamole-aspirin products.

Product	Active ingredient	Typical strength or format	Commercial position
Persantine tablets	Dipyridamole	25 mg, 50 mg, 75 mg	Legacy immediate-release product
Generic dipyridamole tablets	Dipyridamole	25 mg, 50 mg, 75 mg	Primary oral generic market
Dipyridamole injection	Dipyridamole	Commonly 5 mg/mL	Hospital and diagnostic imaging use
Aggrenox	Aspirin plus extended-release dipyridamole	25 mg aspirin/200 mg ER dipyridamole per capsule	Combination antiplatelet product
Generic aspirin/extended-release dipyridamole	Aspirin plus ER dipyridamole	Equivalent combination strength	Generic combination market

The FDA-approved oral Persantine indication was adjunctive therapy with warfarin for patients with prosthetic heart valves. Dipyridamole is also used in other approved or clinically established settings, including pharmacologic myocardial perfusion imaging and secondary stroke prevention when combined with aspirin, depending on the product and labeling pathway.[1][2]

What is the Orange Book status of Persantine?

The economic value of Persantine is not supported by an active brand patent or market exclusivity period. Relevant dipyridamole tablet products are treated as mature products, and generic competition has existed for many years. Orange Book status should be evaluated by product identifier because discontinued brand listings, approved generic products, and combination products can appear under separate entries.[3]

The key regulatory conclusion is straightforward:

• No meaningful new-drug exclusivity remains for dipyridamole.
• No biosimilar pathway applies because dipyridamole is a synthetic small molecule.
• Generic entry is already established for oral dipyridamole.
• New commercial value must come from formulation, delivery, combination, manufacturing, or market-access differentiation.

When does Persantine lose patent exclusivity?

Dipyridamole is an old small molecule whose original composition-of-matter protection expired decades ago. The current commercial question is not whether Persantine has surviving molecule patents. It is whether a new formulation or combination can obtain enforceable, commercially relevant protection.

IP category	Persantine position	Commercial implication
Dipyridamole composition of matter	Expired	No molecule-level barrier to generic entry
Immediate-release tablet	Mature and exposed	Price competition is structurally high
Extended-release dipyridamole	Product-specific patents may have existed or may remain relevant for particular products	Protection depends on claim scope and remaining term
Aspirin plus ER dipyridamole	Separate combination-product estate	Potential method, formulation, and dosage-form claims
Injectable dipyridamole	Mature product category	Manufacturing quality and supply reliability matter more than molecule IP
New excipient system	Potentially patentable	Requires unexpected technical effect and defensible claims
New indication	Potential method-of-use protection	Risk depends on clinical differentiation and label adoption

A new excipient patent cannot recreate expired compound exclusivity. It can protect a specific composition, process, release profile, or use, but the claims must be sufficiently narrow to avoid covering only routine formulation work.

What excipient properties matter most for dipyridamole?

Dipyridamole has formulation characteristics that support targeted excipient development. It has poor aqueous solubility, pH-dependent dissolution behavior, and absorption that can vary with formulation and gastrointestinal conditions.[4] The active ingredient is a weak base with low solubility near neutral pH. These properties create opportunities for solubilization, wetting, particle-size control, precipitation management, and release-rate design.

The primary excipient objectives are:

1. Improve dissolution in the upper gastrointestinal tract.
2. Maintain supersaturation long enough to support absorption.
3. Control precipitation after the dosage form reaches intestinal fluid.
4. Reduce food-related and patient-related variability.
5. Improve taste and redispersibility in liquid products.
6. Protect the drug from moisture and physical instability.
7. Support reliable manufacturing at low dose loading.

Which excipient technologies are suitable for dipyridamole?

Formulation challenge	Candidate excipient strategy	Commercial rationale
Low aqueous solubility	Surfactants, cosolvents, polymeric solubilizers, amorphous solid dispersions	Higher dissolution and potential exposure
Precipitation after dilution	HPMC, PVP, copovidone, Soluplus-type polymers, cellulose derivatives	Maintains supersaturation
Poor wetting	Polysorbates, sodium lauryl sulfate, poloxamers	Improves tablet dispersion and dissolution
Powder-flow limitations	Colloidal silicon dioxide, granulation binders, co-processed excipients	Improves content uniformity and throughput
Bitter or persistent taste	Ion-exchange resins, lipid coating, polymeric taste masking	Enables pediatric and geriatric products
Moisture sensitivity	Blister packaging, desiccant systems, moisture-barrier film coatings	Improves shelf life
Variable release	Hydrophilic matrix polymers, lipid matrices, multiparticulates	Enables once- or twice-daily dosing
Injection acidity or irritation	Buffered vehicle and controlled pH system	Supports tolerability and container compatibility

The best commercial strategy is unlikely to rely on a single generic excipient. A defensible product would combine a defined particle or solid-state form with an excipient system that produces a measurable pharmacokinetic or patient-use advantage.

What formulations are protected by the strongest commercial opportunity?

Modified-release oral tablets or capsules

Immediate-release dipyridamole is commercially vulnerable because the dosage form is familiar, generic, and inexpensive. A modified-release product could reduce dosing frequency or smooth exposure. The closest commercial precedent is extended-release dipyridamole combined with aspirin in Aggrenox and its generic equivalents.[5]

A standalone extended-release dipyridamole product could target patients who require dipyridamole but do not require aspirin or who have aspirin intolerance. Potential technologies include:

• Hydrophilic matrix tablets
• Multiparticulate pellets in capsules
• Osmotic delivery systems
• Coated granules with staged release
• Amorphous solid dispersion combined with controlled-release coating

The commercial hurdle is clinical positioning. A new release profile must produce a useful dosing or tolerability benefit, not merely a different dissolution curve.

Pediatric oral liquid

A ready-to-use or reconstitutable dipyridamole suspension is a practical opportunity. Pediatric dosing may be needed in selected cardiovascular settings, including patients with prosthetic valves or specialized thrombosis-management requirements. Existing tablet products are poorly suited to weight-based dosing.

A successful liquid would need:

• Accurate low-volume dosing
• Taste masking
• Physical stability during shelf life
• Rapid redispersion
• Preservative compatibility
• Low viscosity for oral syringes
• Packaging that limits dosing error
• Flexible concentration, such as 5 mg/mL or another clinically useful strength

Potential taste-masking systems include ion-exchange resin complexes, polymer-coated particles, lipid barriers, and multiparticulate suspensions. The excipient patent should focus on the combination of particle size, coating thickness, release behavior, and suspension stability rather than claiming a generic sweetener system.

Low-dose geriatric formulation

Older patients may have difficulty swallowing conventional tablets. Commercial options include:

• Orally disintegrating tablets
• Mini-tablets
• Sprinkle capsules
• Powder sachets
• Smaller tablets with high content uniformity

An orally disintegrating formulation must balance rapid disintegration against the poor solubility of dipyridamole. Superdisintegrants alone will not solve the dissolution problem. A practical design could use micronized or nanostructured dipyridamole with a wetting agent and a precipitation-inhibiting polymer.

Combination products

Dipyridamole-aspirin remains the most commercially established differentiated formulation. A new combination opportunity would need a clear advantage over existing extended-release products, such as:

• Lower gastrointestinal burden
• Reduced pill burden
• More consistent dipyridamole exposure
• Alternative aspirin release location
• Improved adherence packaging
• A dose ratio for a defined patient subgroup

Combination-product patents may cover composition, release timing, capsule architecture, and methods of preventing platelet aggregation. The regulatory strategy would depend on whether the product is an abbreviated new drug application, a 505(b)(2) application, or another applicable pathway.[6]

How strong is the dipyridamole patent estate?

The legacy dipyridamole estate is weak for blocking purposes but potentially useful as prior art for designing around. The stronger opportunity is a new formulation estate with multiple claim layers.

Recommended patent layers

Claim layer	Example subject matter	Strength
Composition	Dipyridamole, polymer, surfactant, and precipitation inhibitor in defined ratios	Moderate if supported by unexpected performance
Solid state	Amorphous dispersion, crystalline form, particle-size distribution	Moderate to strong if reproducible and clinically relevant
Dosage form	Matrix tablet, coated pellet, capsule, suspension, ODT	Moderate
Performance	Dissolution profile, supersaturation duration, food-effect reduction	Stronger if linked to in vivo results
Process	Spray drying, hot-melt extrusion, wet granulation, coating process	Moderate
Packaging	Moisture-control or dose-delivery system	Usually narrow
Method of use	Reduced dosing frequency, improved adherence, selected patient population	Potentially strong but clinically dependent

A patent application built only around common excipients, routine concentrations, and ordinary tablet manufacture would face obviousness risk. The strongest evidence would include comparative data against marketed dipyridamole tablets and aspirin/extended-release dipyridamole products.

What generic entry risks exist for a new Persantine formulation?

A new formulation faces several generic-entry scenarios.

Scenario 1: Immediate-release tablet competition

This is the highest-risk segment. Multiple generic manufacturers can compete on price, and excipient changes are often possible without a meaningful clinical distinction. A new immediate-release tablet should compete through manufacturing cost, supply reliability, packaging, or a niche geographic market rather than premium pricing.

Scenario 2: Modified-release product

Risk is lower if the product has a validated release mechanism and product-specific patents. Generic applicants may file Paragraph IV certifications against listed patents if the product is approved with Orange Book-listed formulation or method patents.[3][7]

The key litigation questions would include:

• Whether the asserted claims cover the generic’s release architecture
• Whether the claims require a specific excipient ratio
• Whether dissolution similarity can be achieved through design-around
• Whether the listed patents claim an approved method of use
• Whether a 30-month stay is available under the applicable filing and listing circumstances

Scenario 3: Pediatric liquid

Generic risk is moderate. A competitor could copy the clinical concentration while changing the suspending agent, flavor system, preservative, or packaging. Patent claims should cover the specific taste-masking mechanism and stability profile, not only the active ingredient concentration.

Scenario 4: Combination product

Generic risk depends on the patent estate and regulatory designation. A combination product may face separate challenges to aspirin release, dipyridamole release, capsule construction, and methods of use. Product-specific litigation can extend the commercial period, but settlement terms and authorized-generic arrangements may materially reduce the value of the patents.

What FDA regulatory pathway best supports commercial differentiation?

A generic immediate-release product would generally use the ANDA pathway. A materially different dosage form, release profile, or excipient system may require a 505(b)(2) application if the applicant relies partly on FDA findings for a listed drug but cannot demonstrate full sameness to the reference product.[6]

Product concept	Likely pathway	Main development burden
Conventional dipyridamole tablet	ANDA	Bioequivalence, CMC, comparative dissolution
New strength of established tablet	ANDA or 505(b)(2), depending on facts	Dose proportionality and bioequivalence
New extended-release dipyridamole	505(b)(2) or ANDA to an ER reference	PK, food effect, release characterization
Pediatric suspension	505(b)(2) or ANDA if a suitable reference exists	Dose uniformity, stability, taste, PK
Dipyridamole-aspirin combination	ANDA or 505(b)(2)	Component-specific release and bioequivalence
New injectable formulation	505(b)(2) or ANDA	Sterility, container closure, impurities, compatibility

The excipient strategy must be designed with the regulatory pathway from the start. A formulation that creates a meaningful pharmacokinetic difference may support a 505(b)(2) product but may not qualify for a straightforward ANDA.

What manufacturing and IP barriers affect dipyridamole products?

The largest practical barriers are not the synthesis of dipyridamole. They are formulation reproducibility, dissolution control, low-dose content uniformity, and scale-up.

Manufacturing barriers

• Maintaining uniform drug distribution at low tablet strengths
• Controlling polymorphic or amorphous material during processing
• Preventing recrystallization in solid dispersions
• Managing residual solvent in spray-dried systems
• Controlling coating weight and release kinetics
• Maintaining suspension particle size during storage
• Preventing adsorption to plastic packaging
• Establishing impurity limits and degradation pathways
• Qualifying reliable sources for pharmaceutical-grade polymers and surfactants

A manufacturing patent can be commercially useful where the process produces a measurable quality advantage, such as tighter dissolution variability or improved amorphous-state stability. Process claims should be supported by scale-up data rather than laboratory-only examples.

Which companies are challenging Persantine exclusivity?

Generic manufacturers have already challenged and displaced the legacy Persantine market through approved dipyridamole products. The competitive field includes established generic companies, contract manufacturers, and specialty developers of hospital injectables or cardiovascular formulations.

The more relevant competitive comparison is between product strategies rather than individual legacy challengers:

Competitor type	Primary advantage	Threat to new product
Low-cost tablet generic	Manufacturing scale	High for immediate-release tablets
Generic aspirin/ER dipyridamole supplier	Existing bioequivalence and market access	High for combination products
Hospital injectable supplier	Sterile manufacturing and contracts	High for injection products
Specialty formulation company	Delivery-system expertise	Moderate to high for ER and pediatric products
Regional pharmaceutical manufacturer	Local registration and distribution	High in price-sensitive markets

What licensing deals could create value?

The most attractive licensing targets would involve enabling technology rather than the Persantine brand itself.

Potential deal structures include:

• In-license of a dipyridamole amorphous dispersion platform
• Co-development of a pediatric suspension
• Regional commercialization rights for an extended-release product
• Supply agreement for a validated dipyridamole intermediate or solid form
• Technology transfer for sterile injectable manufacturing
• Combination-product rights involving aspirin and modified-release dipyridamole

A license should require freedom-to-operate analysis in the United States, European Union, Japan, China, and major emerging markets. Dipyridamole’s molecule-level freedom to operate is broad, but new formulation claims can vary sharply by jurisdiction.

How does Persantine compare with competing antiplatelet products?

Product	Main differentiation	Excipient opportunity	Generic risk
Dipyridamole immediate-release	Mature oral tablet	Limited	Very high
Aspirin	Low-cost antiplatelet	Gastroprotection and modified release	Very high
Aspirin/ER dipyridamole	Combination and extended release	Release synchronization and tolerability	High
Clopidogrel	Once-daily P2Y12 inhibition	Solid-state and stability systems	High
Ticagrelor	Reversible P2Y12 inhibition	Solubility and taste masking	Moderate to high, depending on market
Injectable dipyridamole	Diagnostic vasodilator use	Sterility, compatibility, ready-to-use presentation	Moderate

Dipyridamole’s commercial weakness is low price and established generic competition. Its development advantage is formulation flexibility: poor solubility, release control, liquid-dose needs, and combination use create several technically distinct product concepts.

What is the commercial opportunity for a new Persantine formulation?

The strongest opportunity ranking is:

1. Pediatric or geriatric oral liquid with clinically useful dosing accuracy.
2. Standalone extended-release dipyridamole for patients who do not need aspirin.
3. Improved aspirin/extended-release dipyridamole combination with adherence or tolerability benefits.
4. Ready-to-use hospital injection with improved packaging and supply reliability.
5. Low-cost immediate-release tablet for underserved or fragmented markets.

The weakest opportunity is another conventional 25 mg, 50 mg, or 75 mg immediate-release tablet without a manufacturing or distribution advantage.

Key Takeaways

• Persantine’s original molecule exclusivity has expired, and the immediate-release tablet market is highly exposed to generic competition.
• Dipyridamole’s low solubility and pH-dependent dissolution create genuine formulation opportunities.
• The best excipient strategies combine solubilization with precipitation control, taste masking, or release modulation.
• A pediatric suspension, geriatric dosage form, or standalone extended-release product offers greater commercial potential than a standard tablet.
• New patents should claim defined compositions, performance characteristics, solid-state properties, and manufacturing processes.
• A new formulation may require a 505(b)(2) pathway rather than an ANDA if it materially changes release, exposure, or dosage form.
• No biosimilar risk exists because dipyridamole is a synthetic small molecule.
• Generic entry and Paragraph IV risk are highest for products with narrow formulation claims that competitors can design around.
• Geographic value will depend on registration status, local generic density, excipient supply, and hospital or specialty-pharmacy channels.
• Licensing value is more likely to reside in delivery technology and manufacturing capability than in the Persantine brand.

FAQs

Can a new excipient patent extend Persantine exclusivity?

It cannot extend expired molecule protection. It can protect a separate formulation, process, or use if the claims are novel, nonobvious, enabled, and commercially linked to the approved product.

Is dipyridamole suitable for an amorphous solid dispersion?

Yes. Its poor water solubility makes it a logical candidate for polymer-based amorphous dispersions, provided the formulation controls recrystallization, residual solvent, moisture uptake, and long-term physical stability.

Would a dipyridamole oral suspension require new clinical studies?

The requirement depends on the reference product, formulation differences, proposed indication, and regulatory pathway. A 505(b)(2) product may require comparative pharmacokinetic or clinical data beyond a conventional ANDA.

Can a pediatric dipyridamole liquid receive new patent protection?

Yes. Protection may cover the concentration, taste-masking system, suspension architecture, preservative system, dosing device, stability profile, or a defined manufacturing process.

Is dipyridamole injection a stronger commercial opportunity than oral Persantine?

It can be stronger in markets where sterile supply reliability and diagnostic imaging contracts support pricing. The opportunity depends on hospital procurement, existing injectable suppliers, manufacturing compliance, and the ability to offer a differentiated ready-to-use presentation.

References

1. U.S. Food and Drug Administration. (n.d.). Persantine (dipyridamole) prescribing information. DailyMed.

2. U.S. Food and Drug Administration. (n.d.). Dipyridamole injection prescribing information. DailyMed.

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

4. Dressman, J. B., Amidon, G. L., Reppas, C., & Shah, V. P. (1998). Dissolution testing as a prognostic tool for oral drug absorption: Immediate release dosage forms. Pharmaceutical Research, 15(1), 11-22.

5. U.S. Food and Drug Administration. (n.d.). Aggrenox (aspirin and extended-release dipyridamole) prescribing information. DailyMed.

6. U.S. Food and Drug Administration. (2023). Applications covered by Section 505(b)(2). FDA.

7. U.S. Food and Drug Administration. (2024). ANDA submissions: Amendments and reviews under the Hatch-Waxman framework. FDA.