List of Excipients in Branded Drug FELOPDIPINE

Generic Drugs Containing FELOPDIPINE

Company	Ingredient	NDC	Excipient
A-S Medication Solutions	felodipine	50090-7206	ANHYDROUS LACTOSE
A-S Medication Solutions	felodipine	50090-7206	BUTYLATED HYDROXYANISOLE
A-S Medication Solutions	felodipine	50090-7206	BUTYLATED HYDROXYTOLUENE
A-S Medication Solutions	felodipine	50090-7206	CELLULOSE, MICROCRYSTALLINE

What are the Most Frequently-Used Excipients in FELOPDIPINE?

# Of NDCs	Excipient
1	ANHYDROUS LACTOSE
1	BUTYLATED HYDROXYANISOLE
1	BUTYLATED HYDROXYTOLUENE
1	CELLULOSE, MICROCRYSTALLINE

Felodipine Excipient Strategy and Commercial Opportunities

Last updated: August 26, 2026

Felodipine is an established dihydropyridine calcium-channel blocker with high generic competition and no meaningful remaining originator exclusivity barrier. The commercial opportunity is in improving extended-release performance, reducing tablet size, strengthening food-effect control, and developing differentiated formulations for patients who have difficulty swallowing. Excipient selection must address felodipine’s very low aqueous solubility, lipophilicity, light sensitivity, and dependence on controlled release for once-daily dosing.

What is felodipine and how is it currently formulated?

Felodipine is a dihydropyridine calcium-channel blocker approved for hypertension. The marketed reference product, Plendil, is an extended-release tablet administered once daily. Felodipine is practically insoluble in water and is metabolized primarily by CYP3A4, creating potential exposure changes with strong CYP3A4 inhibitors and inducers [1,2].

Attribute	Felodipine
Therapeutic class	Dihydropyridine calcium-channel blocker
Primary indication	Hypertension
Reference product	Plendil extended-release tablets
Common strengths	2.5 mg, 5 mg, 10 mg
Dosage form	Extended-release tablet
Administration	Once daily; tablets should generally be swallowed whole
Solubility profile	Very low aqueous solubility
Metabolism	Predominantly CYP3A4
BCS-relevant issue	Solubility-limited absorption
Main development challenge	Reproducible extended release with controlled food effect

The reference formulation uses a hydrophilic matrix approach. Public labeling identifies excipient classes including microcrystalline cellulose, lactose, hypromellose, colloidal silicon dioxide and coating components. Exact excipient composition differs among manufacturers and strengths [1,3].

Felodipine is commercially important as a generic product but is not an attractive target for a conventional new chemical entity program. Its value is concentrated in formulation engineering, manufacturing efficiency and differentiated delivery.

What excipient properties are most important for felodipine?

The highest-value excipient functions are solubilization, wetting, matrix formation, release-rate control, powder-flow improvement and photoprotection.

Solubilization and wetting

Felodipine’s poor water solubility can produce dissolution-rate limitations, especially at the lower pH conditions of the gastrointestinal tract. Candidate excipient systems include:

• Poloxamers for wetting and micellar solubilization.
• Sodium lauryl sulfate at low concentrations to improve wetting.
• Macrogols or polyethylene glycols in solid-dispersion systems.
• Hydroxypropyl-beta-cyclodextrin or sulfobutyl ether-beta-cyclodextrin for complexation.
• Soluplus, copovidone or hydroxypropyl cellulose for amorphous solid dispersions.
• Lipid excipients such as medium-chain triglycerides, oleic acid derivatives or glyceryl esters for lipid-based delivery.

Surfactant use must be controlled. Excessive surfactant can accelerate drug release from a hydrophilic matrix, increase tablet sensitivity to agitation and create gastrointestinal tolerability issues.

Hydrophilic matrix formation

Hypromellose remains the most practical platform for a generic extended-release tablet. High-viscosity grades can create a hydrated gel layer that slows water penetration and drug diffusion. Low- to medium-viscosity grades can support faster release and smaller tablets.

Other matrix polymers include:

• Polyethylene oxide for stronger gel formation.
• Hydroxypropyl cellulose for erosion and diffusion control.
• Carbomers for pH-sensitive or high-viscosity matrices.
• Ethylcellulose for water-insoluble diffusion barriers.
• Ammonio methacrylate copolymers for membrane-controlled systems.

A mixed polymer system can reduce sensitivity to compression force and tablet geometry. A hydrophilic-hydrophobic matrix may produce a more stable release profile across fed and fasted conditions than a single-polymer system.

Dilution and compressibility

Felodipine doses are low, so the formulation contains a large proportion of excipients. The diluent therefore affects tablet size, content uniformity and manufacturing cost.

Useful diluent options include:

• Microcrystalline cellulose for compactibility and tablet strength.
• Lactose monohydrate for cost-effective volume and flow.
• Mannitol where a lower-lactose or more patient-oriented positioning is desired.
• Dibasic calcium phosphate for robust compression, although it may complicate dissolution control.
• Spray-dried lactose or co-processed excipients for direct compression.

Low-dose content uniformity is a critical quality attribute. A formulation with poor API distribution can fail assay uniformity even when the total blend assay is acceptable. Ordered mixing, geometric dilution, wet granulation or carrier-based deposition may be preferable to simple direct blending.

Which formulation technologies offer the strongest commercial opportunity?

The most credible opportunities are improved extended-release tablets, amorphous solid dispersions and multiparticulate systems.

Improved extended-release matrix tablets

A next-generation generic can use a lower tablet mass, more reproducible release and reduced food sensitivity. The formulation strategy would combine:

1. A wetting or solubilizing excipient.
2. A high-viscosity hydrophilic polymer.
3. A compressible filler.
4. A pH modifier if justified by dissolution data.
5. A protective film coat.

The target profile is once-daily release with minimal dose dumping, limited alcohol sensitivity and comparable pharmacokinetics to the reference product.

The main commercial advantage is manufacturing robustness rather than clinical superiority. A formulation that tolerates normal variation in granule moisture, compression force and coating weight can reduce batch failures and cost of goods.

Amorphous solid dispersions

Amorphous solid dispersions can improve apparent solubility and dissolution rate. Suitable carriers include copovidone, Soluplus, hypromellose acetate succinate and hydroxypropyl cellulose.

The principal risks are physical aging, recrystallization and moisture-driven phase separation. Stabilizers and packaging must be selected together. Aluminum-aluminum blister packaging or high-barrier bottles with desiccant may be necessary, especially if the dispersion has a high amorphous fraction.

A solid dispersion is most commercially attractive when it supports one of the following outcomes:

• A materially smaller tablet.
• A lower excipient burden.
• More consistent exposure at low dose.
• A differentiated oral suspension or sprinkle product.
• A platform that can support multiple strengths.

Multiparticulate and sprinkle formulations

Coated pellets, mini-tablets and granules can provide more consistent gastrointestinal distribution and flexible dose administration. They may be suitable for patients unable to swallow conventional extended-release tablets.

The formulation would require:

• Drug-loaded inert cores or granules.
• A release-controlling polymer coat.
• An overcoat that limits friability and moisture uptake.
• A suitable capsule, sachet or sprinkle presentation.

This approach can create a stronger product profile than a standard tablet, but manufacturing and bioequivalence requirements are more complex. Labeling must prevent crushing or chewing if the release-controlling structure would be damaged.

Liquid and nanosuspension products

An oral liquid could address swallowing difficulties, but felodipine’s low solubility makes a conventional aqueous solution difficult. A nanosuspension, self-emulsifying system or reconstitutable powder may be more feasible.

The commercial value is likely to be limited to defined patient segments because pediatric hypertension is a smaller market than adult hypertension. The product would also face challenges involving dose uniformity, physical stability, preservative selection and administration-device accuracy.

What excipient combinations are technically attractive?

Development objective	Excipient strategy	Main benefit	Main risk
Standard generic ER tablet	Hypromellose plus microcrystalline cellulose and lactose	Low cost and established manufacturing	Food-effect and dissolution variability
Smaller tablet	Solubilizer or amorphous dispersion carrier plus high-functionality filler	Lower tablet mass	Recrystallization or accelerated release
Robust release control	Hypromellose plus ethylcellulose or polyethylene oxide	Reduced sensitivity to agitation	More complex process development
Sprinkle product	Drug-layered pellets plus polymer membrane coat	Swallowing flexibility	Dose-dumping and coating uniformity
Oral liquid alternative	Nanosuspension or self-emulsifying system	Administration to dysphagic patients	Physical instability and device requirements
Lower-lactose positioning	Mannitol or microcrystalline cellulose-based system	Broader excipient acceptability	Larger tablet or weaker compaction
Photostable product	Opaque film coat plus high-barrier packaging	Protects light-sensitive API	Added coating and packaging cost

What formulation patents could protect a felodipine product?

A new felodipine product would have a stronger patent position if claims were directed to a specific, non-obvious combination rather than to routine excipient substitution.

Potential claim areas include:

• A defined amorphous felodipine solid dispersion.
• A specified polymer-to-drug ratio.
• A controlled-release matrix with a narrow dissolution profile.
• A multiparticulate dosage form with defined coating weight gain.
• A formulation with reduced fed-to-fasted pharmacokinetic variation.
• A formulation resistant to alcohol-induced dose dumping.
• A specific manufacturing process that preserves amorphous content.
• A stable nanosuspension or self-emulsifying formulation.
• A low-dose blend process that achieves a defined content-uniformity range.
• A packaging system that maintains chemical and physical stability.

A patent based only on replacing one conventional filler with another would usually have limited strength. Stronger protection would link composition, process and measurable performance characteristics.

When does felodipine lose exclusivity?

Felodipine has already lost original small-molecule exclusivity. Plendil was approved in the United States in 1991, and generic extended-release felodipine products have been marketed for many years [1,4].

Exclusivity category	Felodipine status
New chemical entity exclusivity	Expired
Original compound patent protection	Expired
Reference-product market exclusivity	Expired
Generic competition	Established
Biosimilar pathway	Not applicable
Commercial protection available today	Formulation, process, device, packaging or brand differentiation

The relevant regulatory pathway is an abbreviated new drug application, not a biosimilar application. Felodipine is a small molecule, so competitors generally pursue ANDA approval with comparative bioequivalence and pharmaceutical equivalence requirements.

What is the Orange Book status of felodipine?

The FDA Orange Book historically lists Plendil and approved generic felodipine extended-release products. The core product is subject to ordinary generic substitution, subject to state pharmacy law and product-specific substitution rules [4].

The commercial implications are direct:

• An applicant does not need to overcome an active NCE exclusivity period.
• Paragraph IV litigation is less likely to concern the original active ingredient.
• Any litigation risk would normally arise from later-listed formulation, method-of-use or manufacturing patents.
• A differentiated formulation may pursue 505(b)(2) or ANDA-related strategies depending on how closely it tracks the reference product.

Which companies are challenging felodipine exclusivity?

Generic competition has already established the practical loss of felodipine exclusivity. The competitive set has included multiple generic manufacturers and suppliers of extended-release tablets. The market is characterized by price competition, contract manufacturing and pharmacy-channel substitution rather than active challenges to a commercially significant originator patent estate.

No biosimilar competition exists because felodipine is not a biologic. Generic entry risk is high for any conventional felodipine tablet without meaningful formulation differentiation.

What patent litigation affects felodipine?

The principal historical barrier, if any, would have involved patents associated with Plendil or its controlled-release formulation. Those protections are no longer a material barrier to routine generic entry. Current commercial risk is more likely to involve:

• ANDA patent certifications for later formulation patents.
• Trade-secret disputes over manufacturing processes.
• Ownership disputes involving solid-dispersion or multiparticulate technology.
• Contract-manufacturing and supply agreements.
• Patent thickets created by a new 505(b)(2) product.

A new formulation developer should avoid relying on a broad claim that covers only “felodipine plus a controlled-release polymer.” Freedom-to-operate analysis should focus on claim construction, priority dates, prosecution history and the jurisdiction in which the product will launch.

What manufacturing and intellectual-property barriers exist?

The main technical barrier is achieving bioequivalent exposure while controlling dissolution across manufacturing scale. Critical process variables include:

• API particle-size distribution.
• Blend homogeneity at low drug load.
• Granulation endpoint and residual moisture.
• Polymer hydration and viscosity.
• Compression force and tablet porosity.
• Coating weight gain.
• Packaging moisture ingress.
• Long-term crystallinity or recrystallization.

The main intellectual-property barrier is likely to be formulation specificity. A product can be commercially differentiated through a narrow combination of excipients, release kinetics and administration format. That combination may support composition, process and method-of-use claims, although enforceability depends on prior art and claim breadth.

How strong is the felodipine patent estate?

The legacy felodipine patent estate is weak as a barrier to standard generic tablets because the foundational exclusivity has expired. A new product-specific estate could be moderate if it demonstrates a measurable performance advantage.

Patent strategy	Likely strength
Conventional hypromellose ER tablet	Low
Specific polymer ratio with validated release advantage	Moderate
Amorphous dispersion with stability data	Moderate to strong
Multiparticulate system with defined coating architecture	Moderate to strong
Manufacturing process tied to product quality	Moderate
Packaging-only claims	Narrow but useful
New therapeutic indication without clinical differentiation	Limited
Routine excipient substitution	Low

Patent value will depend on whether the formulation produces an unexpected result, such as lower food-effect variability, improved stability or resistance to dose dumping.

What licensing deals could support a felodipine product?

The most relevant licensing opportunities involve enabling technologies rather than the felodipine molecule itself. Potential deal categories include:

• Amorphous solid-dispersion platforms.
• Nanocrystal or nanosuspension technology.
• Multiparticulate coating systems.
• Co-processed direct-compression excipients.
• High-barrier blister and desiccant packaging.
• Oral-dose delivery devices.
• Contract development and manufacturing partnerships.

A license is most defensible when the technology reduces development time or creates regulatory differentiation. Licensing a basic filler, lubricant or conventional matrix polymer would rarely provide a durable commercial advantage.

What revenue exposure and launch scenarios exist?

Felodipine revenue exposure is concentrated in generic pricing and supply reliability. A conventional 2.5 mg, 5 mg or 10 mg extended-release tablet would likely face rapid price erosion after entry unless supported by manufacturing scale or a supply agreement.

Launch scenario comparison

Scenario	Product	Market position	Revenue potential
Conventional ANDA	Standard ER tablet	Commodity generic	Low to moderate
High-reliability generic	Robust ER tablet with low failure rate	Preferred supplier or authorized channel	Moderate
505(b)(2) formulation	Smaller tablet or lower food-effect product	Differentiated prescription product	Moderate to high
Sprinkle or mini-tablet	Dysphagia-focused delivery	Niche specialty product	Moderate
Nanosuspension or liquid	Flexible administration	Narrow patient segment	Low to moderate
Platform product	Felodipine plus transferable delivery technology	Portfolio or licensing asset	Potentially high if platform applies broadly

The strongest commercial case is a differentiated extended-release product that can justify a premium through reduced tablet burden, better administration flexibility or improved pharmacokinetic consistency.

Key Takeaways

• Felodipine is an established generic small molecule with expired original exclusivity.
• The primary formulation problem is low aqueous solubility combined with the need for reproducible once-daily release.
• Hypromellose matrix tablets remain the lowest-risk development route.
• Solid dispersions, multiparticulates and sprinkle products offer greater differentiation but increase regulatory and manufacturing complexity.
• Routine excipient substitution has weak patent value.
• Stronger patent opportunities involve defined excipient ratios, release profiles, manufacturing processes and stability outcomes.
• Biosimilar risk is irrelevant; generic substitution risk is high.
• The best commercial opportunity is a differentiated 505(b)(2) or high-reliability generic formulation, not a conventional commodity tablet.
• Packaging and process control are central to maintaining felodipine stability and release performance.

FAQs

Is felodipine suitable for an amorphous solid-dispersion formulation?

Yes. Its low aqueous solubility makes it a candidate for polymer-based amorphous solid dispersions, but recrystallization and moisture sensitivity require long-term physical-stability controls.

Which excipient is best for felodipine extended release?

Hypromellose is the most established starting polymer for an extended-release matrix. The optimum grade and concentration depend on tablet geometry, drug loading, dissolution targets and food-effect performance.

Can felodipine be developed as a pediatric oral liquid?

Yes, but a conventional aqueous solution is technically difficult because of poor solubility. A nanosuspension, self-emulsifying system or reconstitutable formulation would be more practical.

Does felodipine have biosimilar competition?

No. Felodipine is a chemically synthesized small molecule. Competition occurs through generic ANDA products, not biosimilars.

What is the most defensible patent strategy for a new felodipine product?

The strongest strategy would combine composition claims with process and performance claims covering a specific release architecture, improved stability, reduced food effect or flexible administration format.

References

1. U.S. Food and Drug Administration. (2019). Plendil (felodipine) extended-release tablets: Prescribing information. FDA.

2. National Center for Biotechnology Information. (2024). Felodipine compound summary. PubChem. https://pubchem.ncbi.nlm.nih.gov/

3. DailyMed. (2024). Felodipine extended-release tablets: Product labeling. U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/

4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm