List of Excipients in Branded Drug ISORDIL

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Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Bausch Health US LLC	ISORDIL	isosorbide dinitrate	0187-0152	FD&C RED NO. 40
Bausch Health US LLC	ISORDIL	isosorbide dinitrate	0187-0152	LACTOSE
Bausch Health US LLC	ISORDIL	isosorbide dinitrate	0187-0152	MAGNESIUM STEARATE

Isordil Excipient Strategy and Commercial Opportunities for Isosorbide Dinitrate

Last updated: September 6, 2026

Isordil is the legacy brand for isosorbide dinitrate, an organic nitrate used for angina pectoris. Its active-ingredient patent barriers are largely historical. Current commercial opportunities center on low-cost generic supply, sublingual performance, improved stability, differentiated dosage forms, hospital and long-term-care channels, and excipient systems that support rapid drug release without compromising nitrate stability.

The most attractive formulation targets are sublingual tablets, immediate-release oral tablets, orally disintegrating tablets, and potentially unit-dose products for adherence-sensitive patients. Biosimilar risk does not apply because isosorbide dinitrate is a small-molecule drug, not a biologic.

What is Isordil and how is isosorbide dinitrate marketed?

Isordil contains isosorbide dinitrate, commonly abbreviated ISDN. The product has historically been marketed in oral and sublingual tablet strengths, including 5 mg, 10 mg and 20 mg presentations. Generic isosorbide dinitrate products are available in the United States and other markets.

Attribute	Isordil and isosorbide dinitrate
Active ingredient	Isosorbide dinitrate
Therapeutic class	Organic nitrate; antianginal
Main indication	Prevention or treatment of angina associated with coronary artery disease
Dosage forms	Sublingual and oral immediate-release tablets
Regulatory category	Prescription small-molecule drug
U.S. reference product	Isordil legacy brand products
Generic pathway	Abbreviated New Drug Application, or ANDA
Biosimilar exposure	None
Key formulation issue	Rapid dissolution and dose uniformity with adequate chemical and physical stability
Commercial status	Mature generic market with limited brand-driven pricing power

Isosorbide dinitrate is subject to nitrate tolerance. Product regimens generally require a daily nitrate-free interval, which affects prescribing, adherence and packaging strategy. The drug is also metabolized to isosorbide-2-mononitrate and isosorbide-5-mononitrate, which have their own commercial products and therapeutic positioning.

What excipients are used in Isordil and generic isosorbide dinitrate tablets?

The exact excipient composition varies by manufacturer, dosage form, strength and market. Historical Isordil and generic tablet formulations have used conventional excipients such as lactose, starch, cellulose derivatives, povidone, colloidal silicon dioxide, talc and magnesium stearate. The excipient system must be confirmed against the current manufacturer label and product-specific regulatory filing.

A typical immediate-release tablet platform may include:

Excipient function	Candidate materials	Relevance to isosorbide dinitrate
Diluent	Lactose, microcrystalline cellulose, mannitol, dibasic calcium phosphate	Controls tablet size, compressibility and mouthfeel
Binder	Povidone, pregelatinized starch, hydroxypropyl cellulose	Supports granule strength and content uniformity
Disintegrant	Crospovidone, croscarmellose sodium, sodium starch glycolate	Promotes rapid tablet breakup
Lubricant	Magnesium stearate, sodium stearyl fumarate	Controls ejection force and manufacturing throughput
Glidant	Colloidal silicon dioxide	Improves powder flow and dose uniformity
Sweetener or flavor	Sucralose, saccharin sodium, aspartame, mint flavor	Relevant to sublingual and orally disintegrating products
Film coating	Hypromellose, polyethylene glycol, titanium dioxide, colorants	Improves handling, identification and light protection
Moisture-control excipient	Selected high-density or low-moisture grades	May reduce degradation risk during storage

Lactose-based systems can provide acceptable manufacturability at low drug load, but lactose, water activity and processing conditions must be evaluated together. Microcrystalline cellulose and mannitol can support direct compression and improve patient acceptability, particularly in orally disintegrating tablets.

What excipient strategy best supports sublingual Isordil products?

The highest-value formulation objective is rapid and reproducible drug release in the oral cavity. A sublingual formulation should disintegrate quickly, avoid excessive friability and minimize unpleasant taste without creating a barrier to dissolution.

A practical sublingual excipient strategy includes:

1. A directly compressible diluent such as mannitol or microcrystalline cellulose.
2. A fast-acting disintegrant such as crospovidone or croscarmellose sodium.
3. A low-level binder that preserves rapid disintegration.
4. A lubricant system that does not create excessive hydrophobicity.
5. A taste-masking approach that does not delay drug liberation.
6. Packaging that controls moisture and light exposure.

Mannitol is commercially attractive because it provides a cooling mouthfeel and is compatible with orally disintegrating platforms. Its use can improve patient acceptance but may increase tablet friability if the formulation is not optimized. Microcrystalline cellulose improves compactability but can create a less pleasant mouthfeel at higher concentrations.

Crospovidone often supports rapid capillary-driven water uptake. Croscarmellose sodium provides swelling-based disintegration. The selection should be based on dissolution and disintegration data rather than excipient convention.

Magnesium stearate requires particular control. Excessive concentration or over-lubrication can reduce wettability and slow dissolution. Sodium stearyl fumarate may provide an alternative where faster wetting or reduced hydrophobicity is needed.

What formulation patents could protect improved Isordil products?

An ordinary isosorbide dinitrate tablet is unlikely to support a strong modern patent position solely because it uses a conventional filler, binder or lubricant. A defensible patent position would more likely require a technically differentiated formulation or manufacturing process.

Potential claim categories include:

Potential claim area	Commercial relevance	Patent strength
Fast-disintegrating sublingual tablet	Supports rapid administration and differentiation from standard tablets	Moderate if supported by unexpected performance
Taste-masked dosage form	Improves adherence and patient acceptance	Moderate; dependent on masking technology
Moisture- or light-stabilized formulation	Extends shelf life and reduces degradation	Moderate to strong if stability improvement is demonstrated
Specific particle-size distribution	Can improve content uniformity and dissolution	Low to moderate unless linked to unexpected results
Spray-dried or co-processed excipient system	May improve flow, compression or disintegration	Moderate
Orally disintegrating tablet	Supports patient convenience	Low to moderate unless the formulation solves a specific technical problem
Unit-dose blister package	Reduces handling and may support stability	Low unless packaging produces a measurable stability benefit
Modified-release product	Changes exposure profile and dosing frequency	Potentially strong, but clinical and regulatory requirements increase

Method-of-use patents could cover specific dosing schedules, nitrate-free intervals, patient populations or combination regimens. Their commercial value would depend on physician adoption, labeling support and enforceability. A formulation patent that covers only an excipient substitution would generally face a greater obviousness challenge than a patent tied to unexpected dissolution, stability or bioavailability results.

When did Isordil lose exclusivity?

Isordil is a mature product. The principal commercial barriers associated with the original brand have expired or ceased to be commercially significant. Generic isosorbide dinitrate products have been marketed for many years, and the market is not dependent on a current brand patent monopoly.

The practical exclusivity position is:

Exclusivity category	Current commercial assessment
Original active-ingredient patent	Expired or commercially irrelevant
Basic oral tablet formulation	No meaningful current barrier
Sublingual tablet technology	Legacy protection does not prevent established generic competition
New formulation patents	Possible for a newly developed product, subject to novelty and obviousness
Orphan exclusivity	Not applicable
Pediatric exclusivity	No current commercial significance identified
Regulatory exclusivity	No active new-drug exclusivity expected for the mature product
Biosimilar exclusivity	Not applicable

The Orange Book is the relevant U.S. source for listed patents, therapeutic-equivalence ratings and reference-product information. For a discontinued legacy brand, the commercial analysis should distinguish historical approval records from currently marketed reference products. The absence of a meaningful current patent barrier shifts value toward manufacturing economics, supply reliability and dosage-form differentiation.[1]

What is the Orange Book status of Isordil?

Isordil is associated with legacy FDA approval records rather than an active innovative-drug franchise. Current generic applicants typically rely on the applicable reference product and demonstrate pharmaceutical equivalence, bioequivalence and manufacturing compliance through an ANDA.

For an isosorbide dinitrate product, the relevant Orange Book diligence includes:

• Whether the reference listed drug remains actively marketed.
• Whether the proposed dosage form matches the reference product.
• Whether any listed patent or exclusivity entry remains active.
• Whether the product has an AB therapeutic-equivalence rating.
• Whether the applicant must submit a Paragraph IV certification.
• Whether the product is eligible for an abbreviated pathway or requires a different regulatory submission.

A new sublingual, orally disintegrating or modified-release presentation may not qualify as a straightforward copy of an existing reference product. The regulatory pathway could require additional clinical, pharmacokinetic or local-performance evidence depending on the dosage form and labeling.

Are Paragraph IV challenges relevant to Isordil?

Paragraph IV litigation is unlikely to be a central risk for conventional generic isosorbide dinitrate because the original brand-related protection is legacy protection. Paragraph IV risk becomes relevant if a company develops a newly patented formulation, delivery system, packaging configuration or method of use.

Potential Paragraph IV scenarios include:

Scenario	Likely consequence
Generic challenges a listed formulation patent	Patent litigation and possible 30-month stay
Generic uses a formulation outside the patent claims	Lower litigation exposure, but claim construction remains important
New branded ODT receives formulation patents	Later ANDA entrants may certify against those patents
Patent owner relies on method-of-use claims	Label carve-out strategy may become important
Patent is not listed in the Orange Book	Paragraph IV certification may not be available for that patent

For a new differentiated Isordil product, patent listing strategy would require claims that cover the approved product and meet Orange Book listing requirements. Manufacturing know-how, supplier agreements and trade secrets may be more practical than patents for protecting a low-margin generic product.

What manufacturing and excipient barriers affect isosorbide dinitrate?

Manufacturing barriers are moderate rather than high. The active ingredient is a small molecule with established tablet-processing history, but low-dose products create content-uniformity challenges. The formulation must distribute a relatively small amount of active ingredient evenly through the blend.

Key process risks include:

• Segregation during blending or transfer.
• Over-lubrication and slowed dissolution.
• Tablet capping or lamination at high compression force.
• Poor sublingual mouthfeel.
• Moisture-related stability changes.
• Light exposure during processing and packaging.
• Inconsistent particle-size distribution.
• Loss of assay uniformity at low strengths.

A high-value manufacturing platform would use a controlled premix or granulation process, validated blend uniformity and low-shear handling. Direct compression can reduce cost and processing steps, but it requires reliable powder flow and compressibility. Wet granulation may improve uniformity but introduces water and drying controls that may increase process complexity.

Supplier qualification is commercially important. A generic manufacturer may obtain a modest advantage through access to consistent direct-compression mannitol, low-moisture cellulose, specialized disintegrants or co-processed excipients. Those advantages are rarely absolute barriers, but they can reduce batch failure and improve scale-up performance.

What commercial opportunities exist for Isordil excipient innovation?

The strongest opportunities are in product differentiation rather than active-ingredient exclusivity.

Sublingual and orally disintegrating tablets

A rapidly disintegrating tablet could target patients who need administration without water or who have difficulty swallowing. The product would require robust control of disintegration, dissolution, friability, taste and dose uniformity.

Unit-dose and adherence packaging

Calendar blister packs and unit-dose pouches could align with nitrate-free dosing schedules. Packaging can also limit exposure to moisture and light. The commercial value is greater in long-term-care, hospital discharge and chronic-care settings than in a purely commodity pharmacy channel.

Low-cost hospital and institutional supply

Isosorbide dinitrate remains relevant to hospitals, clinics and long-term-care facilities. Institutional buyers value predictable supply, stable pricing, barcoded unit doses and low dispensing complexity. A manufacturer with reliable supply and multiple strengths may gain share even without a patented formulation.

Global-market reformulation

In emerging markets, smaller tablets, simplified packaging and heat- and humidity-resilient formulations may create opportunities. Regulatory requirements, reference-product availability and local pharmacopoeial standards vary by jurisdiction. A formulation designed for high humidity and broad temperature excursions may have practical value even without premium pricing.

Combination and co-pack strategies

Isosorbide dinitrate has potential for co-packaging with complementary cardiovascular therapies, subject to prescribing, labeling and regulatory constraints. A co-pack is generally easier to commercialize than a fixed-dose combination because it does not change the approved active-ingredient formulation. The strategy can support adherence and channel positioning but is unlikely to generate strong patent exclusivity by itself.

How does Isordil compare with nitroglycerin and isosorbide mononitrate?

Isordil competes with nitroglycerin and isosorbide mononitrate, but the products have different dosage and positioning characteristics.

Product	Main commercial role	Formulation opportunity	Competitive constraint
Isosorbide dinitrate	Sublingual relief and oral angina management	Fast-disintegrating tablet, taste masking, unit dose	Mature generic pricing
Nitroglycerin	Rapid relief of acute angina; tablets, sprays and patches	Spray delivery, stability packaging, convenient dosing	Strong physician familiarity and multiple dosage forms
Isosorbide mononitrate	Chronic prophylaxis, often once- or twice-daily	Extended-release and adherence-focused products	More convenient dosing and established generic competition

Isosorbide mononitrate may have an adherence advantage because dosing can be simpler. Isosorbide dinitrate can remain competitive where rapid sublingual administration, lower acquisition cost or established institutional protocols matter.

What licensing opportunities exist for Isordil excipients and delivery systems?

Publicly identifiable licensing value is more likely to arise from enabling technologies than from the Isordil brand itself. Relevant licensing targets include:

• Co-processed excipient systems for direct compression.
• Taste-masking technologies compatible with rapid dissolution.
• Orally disintegrating tablet platforms.
• Moisture- and light-barrier blister packaging.
• Low-dose content-uniformity manufacturing processes.
• Digital adherence packaging for cardiovascular medicines.

A licensee would need to assess whether the technology creates measurable advantages in stability, dissolution, manufacturing yield or patient acceptance. A generic product with a higher excipient cost requires a clear commercial return. For a mature drug, the preferred structure may be a nonexclusive technology license, contract manufacturing arrangement or supply agreement rather than acquisition of a standalone patent estate.

No current blockbuster-scale licensing franchise is associated with Isordil. The commercial case is operational and formulation-based.

What revenue exposure and generic launch risks exist?

Revenue exposure is concentrated in generic volume rather than branded price premium. Product-level Isordil revenue is not a reliable indicator of market size because sales may be reported within broader cardiovascular portfolios, discontinued-brand categories or generic business units.

Generic launch risks include:

1. Low market price and limited gross margin.
2. Multiple approved suppliers.
3. Pharmacy substitution and wholesaler purchasing power.
4. Periodic shortages caused by active-ingredient or packaging disruptions.
5. Low clinical differentiation among standard tablets.
6. Limited return on expensive clinical development.
7. Regulatory complexity for new dosage forms.
8. Potential cannibalization between oral and sublingual presentations.

A differentiated product can improve economics if it wins institutional contracts, supports a branded-generic price premium or reduces manufacturing costs. An excipient change alone is unlikely to support a durable premium unless it produces a validated clinical, stability or usability benefit.

How strong is the Isordil patent estate?

The legacy Isordil patent estate is weak as a current commercial barrier. The active ingredient and conventional tablet technology are mature, genericized and widely understood.

Patent dimension	Assessment
Active ingredient	Weak current protection
Conventional tablet composition	Weak
Sublingual dosage form	Limited protection absent a novel technical feature
Taste masking	Potentially protectable
Stability-enhanced formulation	Potentially protectable with supporting data
Modified release	Potentially stronger, but requires more development
Manufacturing process	Better protected as trade secret unless patent claims capture a non-obvious process
Packaging	Usually modest patent strength
Method of use	Dependent on approved labeling and claim scope

The strongest defensible strategy would combine a narrow formulation patent with manufacturing know-how, regulatory exclusivity where available, trademarks and supply-chain control.

Key Takeaways

• Isordil is the legacy brand for isosorbide dinitrate, a mature genericized organic nitrate.
• Current value is concentrated in formulation execution, manufacturing reliability and distribution rather than legacy active-ingredient patents.
• Mannitol, microcrystalline cellulose, crospovidone and carefully controlled lubrication are credible platforms for sublingual or orally disintegrating tablets.
• The most defensible new patent claims would target measurable improvements in dissolution, stability, taste masking, dose uniformity or modified release.
• Biosimilar risk does not apply.
• Paragraph IV risk is limited for legacy Isordil but could arise against newly patented formulations.
• The strongest commercial opportunities are fast-disintegrating tablets, adherence packaging, institutional supply and heat- or humidity-resilient products.
• Generic launch economics are constrained by substitution, low pricing and established competitors.
• A successful strategy should combine excipient optimization with packaging, process control and channel-specific commercialization.

FAQs

Can lactose be used in an isosorbide dinitrate tablet?

Yes. Lactose is a conventional tablet diluent, but the formulation must meet requirements for blend uniformity, stability, dissolution and compatibility with the selected manufacturing process.

Is Isordil suitable for an orally disintegrating tablet?

Yes, technically. The main development issues are taste, friability, dose uniformity, rapid disintegration and preservation of drug release after exposure to saliva.

Does Isordil have biosimilar competition?

No. Isosorbide dinitrate is a small-molecule active ingredient. Competition proceeds through generic-drug pathways rather than the biosimilar pathway.

Could a new Isordil formulation receive market exclusivity?

A new formulation may qualify for patent protection and, depending on the regulatory pathway, certain regulatory protections. Conventional excipient substitution alone is unlikely to create strong exclusivity.

Which excipient is best for rapid sublingual disintegration?

No single excipient is universally best. Mannitol can improve mouthfeel, while crospovidone or croscarmellose sodium can support rapid disintegration. Performance depends on the complete formulation, compression conditions and lubricant level.

References

1. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book

2. U.S. Food and Drug Administration. (n.d.). Isosorbide dinitrate drug labels and approval information. Drugs@FDA. https://www.accessdata.fda.gov/scripts/cder/daf/

3. National Library of Medicine. (n.d.). DailyMed: Isosorbide dinitrate tablet labeling. https://dailymed.nlm.nih.gov/dailymed/

4. United States Pharmacopeial Convention. (2024). United States Pharmacopeia and National Formulary, USP 47-NF 42. U.S. Pharmacopeial Convention.

5. U.S. Food and Drug Administration. (2018). Quality considerations for chewable tablets: Guidance for industry. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/quality-considerations-chewable-tablets-guidance-industry