List of Excipients in Branded Drug TIADYLT ER

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Generic Drugs Containing TIADYLT ER

Company	Ingredient	NDC	Excipient
Zydus Pharmaceuticals (USA) Inc	diltiazem hydrochloride	68382-745	ETHYLCELLULOSES
Zydus Pharmaceuticals (USA) Inc	diltiazem hydrochloride	68382-745	FD&C BLUE NO. 1
Zydus Pharmaceuticals (USA) Inc	diltiazem hydrochloride	68382-745	FD&C RED NO. 3
Zydus Pharmaceuticals (USA) Inc	diltiazem hydrochloride	68382-745	FD&C RED NO. 40

What are the Most Frequently-Used Excipients in TIADYLT ER?

# Of NDCs	Excipient
2	ETHYLCELLULOSE
2	ETHYLCELLULOSES
4	FD&C BLUE NO. 1
4	FD&C RED NO. 3

Tiadylt ER Excipient Strategy, Formulation Patents, and Commercial Opportunities

Last updated: October 5, 2026

Tiadylt ER is an extended-release oral capsule containing diltiazem hydrochloride, a calcium-channel blocker used primarily for hypertension and chronic stable angina. Its commercial opportunity is based on manufacturing efficiency, reliable release performance, supply continuity, and differentiated packaging rather than molecule-level patent exclusivity. The core active ingredient and established diltiazem extended-release technology are mature, leaving excipient selection and process control as the main sources of competitive value.

What is Tiadylt ER and who markets it?

Tiadylt ER is a once-daily extended-release diltiazem hydrochloride capsule. The product is available in multiple strengths, generally ranging from 120 mg to 420 mg, depending on the marketed presentation and current labeling.

Product attribute	Tiadylt ER
Active ingredient	Diltiazem hydrochloride
Dosage form	Extended-release capsule
Route	Oral
Therapeutic class	Calcium-channel blocker
Primary uses	Hypertension and chronic stable angina
Release profile	Extended release over approximately 24 hours
Regulatory pathway	Abbreviated or hybrid regulatory pathway depending on the specific application and jurisdiction
Reference-product class	Diltiazem extended-release capsule products, including Cardizem CD-type presentations
Prescription status	Prescription drug
Biosimilar relevance	None; diltiazem is a small-molecule drug

The principal commercial issue is substitution among several diltiazem extended-release products. Prescribers, wholesalers, pharmacies and payers generally evaluate these products through therapeutic equivalence, price, supply reliability, dosage-strength availability and tolerability.

What excipients are used in Tiadylt ER?

The Tiadylt ER label identifies a multiparticulate extended-release formulation. Public labeling identifies excipient classes used in the capsule and coated-bead system, although the exact quantitative composition is generally not disclosed.

Reported excipient categories include:

• Sugar spheres or sucrose-based inert cores
• Microcrystalline cellulose
• Hypromellose
• Povidone
• Ethylcellulose or another hydrophobic release-controlling polymer
• Talc
• Titanium dioxide
• Polyethylene glycol
• Gelatin
• Colorants, including iron oxides or other approved capsule pigments depending on strength

The formulation is consistent with a multiparticulate pellet design. Diltiazem-containing drug layers are applied to starter cores and then coated with polymers that control water penetration and drug diffusion. Pellets are filled into hard gelatin capsules.

Why the pellet platform matters

Multiparticulate capsules distribute the dose across numerous coated units. This can reduce the effect of local manufacturing defects compared with a single monolithic matrix tablet. It also allows the manufacturer to adjust release by changing:

• Drug-layer thickness
• Polymer type
• Polymer weight gain
• Plasticizer level
• Pore-former concentration
• Pellet size distribution
• Capsule fill weight
• Ratio of immediate-release and extended-release pellet populations

The platform creates manufacturing complexity, but it also permits fine adjustment of dissolution performance. The commercial objective is to reproduce the reference-product release profile across all strengths while maintaining robust scale-up performance.

How does the Tiadylt ER excipient strategy control drug release?

Tiadylt ER likely relies on a diffusion-controlled coating system rather than a simple immediate-release capsule filled with uncoated powder.

The main functional excipient groups are:

Excipient group	Technical function	Commercial significance
Sucrose or microcrystalline cellulose cores	Provides a uniform substrate for drug layering	Controls pellet size, coating uniformity and yield
Hypromellose	Binder and film-forming polymer	Supports adhesion of the drug layer
Povidone	Binder and processing aid	Improves drug-layer cohesion
Ethylcellulose or similar polymer	Limits water ingress and drug diffusion	Determines extended-release behavior
Talc	Anti-tacking and processing aid	Reduces pellet agglomeration during coating
Polyethylene glycol	Plasticizer	Improves flexibility of polymer films
Gelatin	Capsule shell	Enables dose presentation and color coding
Titanium dioxide and iron oxides	Opacifiers and colorants	Supports product identification and light protection

The key quality attributes are dissolution at multiple time points, assay, content uniformity, pellet size, coating weight gain, moisture, capsule fill weight and stability. Small changes in polymer concentration, coating temperature or spray rate can shift the dissolution profile.

What formulation patents protect Tiadylt ER?

Tiadylt ER does not appear to depend on a current, enforceable composition-of-matter patent for diltiazem. Diltiazem itself is an old active pharmaceutical ingredient, and the original molecule-level exclusivity has expired.

The relevant intellectual-property categories are formulation and process rights:

1. Multiparticulate pellet manufacture
2. Controlled-release polymer coatings
3. Drug-layering processes
4. Capsule filling and pellet blending
5. Dissolution-control methods
6. Stability and moisture-control processes
7. Manufacturing equipment and process parameters

Public FDA Orange Book records should be checked for current patent listings associated with the specific Tiadylt ER application. No broadly recognized, unexpired Orange Book patent is generally associated with the mature diltiazem extended-release product class. That does not eliminate the possibility of non-Orange-Book patents, trade secrets or manufacturing know-how.

IP category	Tiadylt ER exposure
Diltiazem composition patent	Expired
Basic extended-release diltiazem patents	Generally expired or near the end of enforceable life
Current Orange Book patent barrier	No widely recognized blocking patent identified
Formulation know-how	Potentially important
Process trade secrets	Potentially important
Method-of-use patents	Limited commercial significance for established indications
Patent-based generic delay	Low
Regulatory exclusivity	No current practical exclusivity expected for the mature product

The commercial barrier is therefore more likely to be regulatory equivalence and manufacturing execution than patent infringement.

When does Tiadylt ER lose exclusivity?

Tiadylt ER has no meaningful remaining molecule-level exclusivity. Diltiazem has been marketed for decades, and multiple generic extended-release formulations are available.

Any period of regulatory exclusivity associated with a later-approved Tiadylt ER application would have been time-limited. A three-year exclusivity period may apply to certain applications containing new clinical investigation data, but such exclusivity does not create a new patent term for diltiazem and does not generally block all abbreviated applications indefinitely.

The relevant distinction is:

• Patent exclusivity protects legally defined inventions.
• Regulatory exclusivity restricts certain approval pathways for a defined period.
• Therapeutic equivalence determines pharmacy substitution after approval.
• Commercial exclusivity can persist temporarily through supply contracts, brand recognition or distribution control.

For Tiadylt ER, regulatory and commercial barriers are more relevant than basic patent expiry.

What is the Orange Book status of Tiadylt ER?

The Orange Book identifies approved drug products, therapeutic-equivalence evaluations and, where applicable, listed patents and exclusivity information. A Tiadylt ER review should examine:

• The exact NDA or ANDA number
• Active ingredient and dosage form
• Strength-specific listings
• Therapeutic-equivalence code
• Patent-use codes
• Listed patent expiration dates
• Regulatory exclusivity codes
• Reference-listed drug status

Diltiazem extended-release capsules are generally evaluated against established reference products rather than protected by a current composition patent. A generic competitor would typically focus on demonstrating bioequivalence and comparable in vitro release, not on overcoming a long-lived active-ingredient patent.

Paragraph IV challenge risk

Paragraph IV risk is structurally low for the underlying diltiazem molecule because core patents are expired. If a later patent were listed for a specific formulation or use, an applicant could challenge it through a Paragraph IV certification. The practical value of such a challenge would depend on:

• Whether the patent is listed against the precise product
• Whether the patent claims the applicant’s formulation
• Whether the patent is enforceable
• Whether the patent owner files suit within the statutory period
• Whether a 30-month stay applies
• Whether the applicant can design around the claims

For a mature diltiazem extended-release product, a Paragraph IV strategy would usually target a narrow formulation claim, not the active ingredient.

What generic launch risks exist for Tiadylt ER?

Generic entry risk is high because diltiazem is chemically established, clinically familiar and available from multiple suppliers. The main launch risks are operational.

Risk	Impact on a generic entrant	Mitigation
Dissolution mismatch	FDA deficiency or failure to demonstrate equivalence	Robust comparative dissolution program
Pellet coating variability	Batch failure and inconsistent exposure	In-process coating controls
API supply interruption	Manufacturing downtime	Dual-source qualification
Capsule color or imprint changes	Product confusion and medication errors	Strong visual differentiation
Strength gaps	Lost pharmacy and wholesaler volume	Launch broad strength portfolio
Stability failure	Short shelf life or recalls	Moisture and packaging optimization
Low reimbursement	Margin compression	Low-cost process and selective contracting
Wholesaler consolidation	Limited channel access	Multiple distribution partners
Therapeutic substitution concerns	Prescriber or pharmacist resistance	Clear equivalence and supply record

A generic manufacturer that can reliably produce all major strengths has a stronger commercial position than a company offering only one or two dosage levels.

What commercial opportunities exist in Tiadylt ER excipients?

The opportunity is not limited to selling commodity excipients. Suppliers can compete through functional performance, regulatory support and process integration.

Functional coating polymers

Ethylcellulose and related controlled-release polymers are central to the release profile. Suppliers can offer differentiated grades with:

• Narrow viscosity distribution
• Consistent particle size
• Lower residual solvent burden
• Improved aqueous dispersion
• More predictable coating weight gain
• Better batch-to-batch dissolution reproducibility

A manufacturer may accept a higher unit price if the polymer reduces coating defects, rework and release testing failures.

Ready-to-use coating systems

Pre-formulated coating systems can combine polymer, plasticizer, anti-tacking agent and pigment. These systems reduce formulation development time and simplify manufacturing. They can be positioned for:

• Diltiazem extended-release capsules
• Verapamil modified-release products
• Nifedipine extended-release formulations
• Other multiparticulate cardiovascular products

The commercial value is strongest where the supplier provides a validated process window rather than only a raw material.

Starter cores and pellet substrates

Uniform sugar spheres and microcrystalline cellulose-based starter cores affect drug-layer uniformity and coating efficiency. Suppliers can compete on:

• Tight size distribution
• Low friability
• Low dust generation
• High sphericity
• Consistent moisture
• Improved fluid-bed performance

Starter-core quality can materially affect yield in drug-layering operations.

Capsule shells and color systems

Capsule suppliers can offer strength-specific color coding, low-moisture gelatin and alternative shell materials. Opportunities include:

• Improved moisture protection
• Reduced brittleness
• Halal or vegetarian capsule options
• Lower pigment migration
• High-speed machine compatibility
• Tamper-evident packaging systems

Capsule differentiation has limited patent value but can support product identification and lifecycle management.

Packaging and stability systems

Diltiazem extended-release pellets may be sensitive to moisture and temperature during storage. Commercial opportunities include:

• High-barrier blister packs
• Desiccant-enabled bottles
• Unit-dose packaging
• Child-resistant packaging
• Improved label systems for strength differentiation
• Serialization and anti-counterfeiting controls

Packaging is particularly relevant for generic products competing on shelf life and distribution reach.

How strong is the Tiadylt ER patent estate?

The patent estate is weak as a blocking asset and potentially stronger as manufacturing know-how.

Dimension	Assessment
Active-ingredient protection	None of practical current value
Broad formulation protection	Limited due to prior-art density
Method-of-use protection	Limited for established indications
Process protection	Potentially meaningful if claims are narrow and unpublished
Trade-secret value	High relative to patent value
Freedom-to-operate complexity	Moderate for multiparticulate release systems
Generic launch vulnerability	High
Licensing value	More likely in manufacturing technology than in the product brand

A formulation patent would face substantial prior-art pressure because controlled-release diltiazem, coated pellets, ethylcellulose systems and capsule-based delivery platforms are established technologies. A defensible patent would need a specific structural limitation, release profile, manufacturing parameter or unexpected performance result.

What licensing deals are relevant to Tiadylt ER?

No major publicly documented licensing transaction is required to commercialize a standard diltiazem extended-release product. Licensing opportunities are more likely to involve:

• Controlled-release coating technology
• Multiparticulate manufacturing equipment
• Proprietary starter cores
• Alternative capsule shells
• Ready-to-use coating dispersions
• Contract manufacturing capacity
• Regional marketing rights
• Approved product dossiers

A licensee should value these assets through manufacturing economics, regulatory transfer risk and time to commercial supply. A broad license to diltiazem technology would have limited value unless it includes validated formulation data, scale-up records, stability data and regulatory support.

How does Tiadylt ER compare with competing diltiazem products?

Product type	Release design	Main competitive issue
Tiadylt ER	Extended-release capsule, likely multiparticulate	Price, supply and pharmacy substitution
Cardizem CD-type products	Extended-release capsule	Brand recognition and reference-product status
Generic diltiazem ER capsules	Capsule-based modified release	Reimbursement and equivalence
Diltiazem ER tablets	Matrix or coated-tablet system	Manufacturing platform and release profile
Immediate-release diltiazem tablets	Multiple daily dosing	Lower formulation complexity but weaker convenience
Diltiazem injection	Parenteral immediate exposure	Hospital and acute-care demand

Tiadylt ER competes primarily with generic capsule products rather than with biologics or biosimilars. The absence of biosimilar risk is commercially important because the principal threat is conventional small-molecule generic competition.

What manufacturing and geographic barriers affect Tiadylt ER?

Geographic barriers arise from regulatory filings, local quality standards, API registration requirements and distribution economics. A product approved in the United States may require separate filings in Europe, Canada, Japan or other markets.

Key barriers include:

• Country-specific bioequivalence requirements
• Site inspection and good manufacturing practice compliance
• Local reference-product selection
• API documentation and impurity controls
• Stability studies under regional climatic conditions
• Serialization requirements
• Language and labeling changes
• Local pharmacovigilance obligations
• Import permits and controlled distribution rules

The most transferable asset is a validated multiparticulate manufacturing process supported by comparative dissolution and stability data. The least transferable asset is a brand name without supply or reimbursement differentiation.

What revenue exposure does Tiadylt ER create?

Revenue exposure depends on the strength portfolio, channel access and net price rather than patent duration. A manufacturer can improve economics through:

• Broad strength coverage
• Reliable wholesaler service levels
• Low-cost pellet coating
• Reduced batch rejection
• Dual-source API procurement
• Private-label and contract manufacturing
• Regional tenders
• Hospital and long-term-care supply
• Authorized generic arrangements

The downside is price erosion after multiple generic entrants. A supplier should model revenue under at least three scenarios:

Scenario	Market condition	Expected commercial result
Premium generic	Few suppliers and strong availability	Higher margin, moderate volume
Competitive generic	Several equivalent suppliers	Lower price, stable volume
Commodity market	Excess capacity and aggressive contracting	Low margin, volume-dependent economics

Key Takeaways

• Tiadylt ER is a mature diltiazem hydrochloride extended-release capsule.
• Its commercial value is driven by formulation execution, supply reliability and distribution rather than active-ingredient patent protection.
• The likely excipient platform includes starter cores, binders, hydrophobic release-control polymers, plasticizers, anti-tacking agents and hard gelatin capsules.
• The most important formulation variables are coating weight gain, pellet size, polymer performance, moisture control and dissolution reproducibility.
• Patent barriers are limited; manufacturing know-how and regulatory equivalence are more important.
• Paragraph IV risk is low for the underlying molecule but could arise from narrow formulation or process patents.
• Excipients with the strongest commercial opportunity are controlled-release polymers, ready-to-use coating systems, high-quality starter cores, capsule shells and high-barrier packaging.
• Generic launch risk is high because diltiazem is mature and multiple competing extended-release products exist.
• Biosimilar competition is irrelevant because diltiazem is a small molecule.
• Licensing value is concentrated in validated manufacturing platforms and regulatory-ready product dossiers.

FAQs

Is Tiadylt ER protected by a diltiazem composition patent?

No. Diltiazem is an established active ingredient, and its original composition-of-matter protection has expired.

Can a generic manufacturer use the same Tiadylt ER excipients?

A generic manufacturer may use the same excipient classes if the formulation complies with regulatory requirements and does not infringe an enforceable patent. Exact composition, process parameters and dissolution performance may differ.

What is the most valuable excipient in Tiadylt ER manufacturing?

The release-controlling polymer is generally the most technically important excipient because it directly affects dissolution, exposure and bioequivalence. Starter-core quality and coating-process control are also critical.

Does Tiadylt ER have biosimilar competition?

No. Biosimilars apply to biological products. Tiadylt ER contains the small-molecule drug diltiazem hydrochloride and competes with generic drug products.

Can a new entrant differentiate a diltiazem extended-release capsule?

Yes. Differentiation can come from improved stability, broader strength coverage, packaging, supply reliability, lower manufacturing cost, alternative capsule materials, validated coating technology or regional distribution rights.

References

1. U.S. Food and Drug Administration. (n.d.). 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.). Electronic Orange Book data files. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book-data-files

3. U.S. Food and Drug Administration. (n.d.). Inactive ingredient database. https://www.accessdata.fda.gov/scripts/cder/iig/index.cfm

4. National Library of Medicine. (n.d.). DailyMed: Tiadylt ER diltiazem hydrochloride extended-release capsule labeling. https://dailymed.nlm.nih.gov/dailymed/

5. U.S. Food and Drug Administration. (2015). Guidance for industry: Waiver of in vivo bioavailability and bioequivalence studies for immediate-release solid oral dosage forms based on a biopharmaceutics classification system. https://www.fda.gov/

6. U.S. Pharmacopeial Convention. (2024). United States Pharmacopeia and National Formulary. USP Convention.