Drugs in ATC Class C08DA

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Drugs in ATC Class: C08DA - Phenylalkylamine derivatives

Tradename	Generic Name
TARKA	trandolapril; verapamil hydrochloride
TRANDOLAPRIL AND VERAPAMIL HYDROCHLORIDE	trandolapril; verapamil hydrochloride
VERAPAMIL HYDROCHLORIDE	verapamil hydrochloride
VERELAN	verapamil hydrochloride

ATC C08DA Phenylalkylamine Derivatives: Market Dynamics and Patent Landscape

Last updated: August 1, 2026

ATC class C08DA covers phenylalkylamine calcium-channel blockers with direct cardiac effects. Verapamil is the principal commercial product; gallopamil has limited or no meaningful current market presence in major regulated markets. The class is dominated by generic immediate-release and extended-release verapamil, with little remaining composition-of-matter protection and limited biosimilar relevance. Commercial value is concentrated in formulation, delivery, manufacturing, and market-specific regulatory rights rather than in active-ingredient patents.

What drugs are included in ATC class C08DA?

ATC C08DA is the phenylalkylamine-derivative subgroup of calcium-channel blockers. The class is narrower than the broader C08 cardiovascular medicines category.

ATC code	Active ingredient	Principal use	Current commercial position
C08DA01	Verapamil	Hypertension, angina, supraventricular tachyarrhythmias, migraine-related and other off-label uses	Widely genericized
C08DA02	Gallopamil	Calcium-channel blockade and antianginal use	Limited commercial availability
Related but outside C08DA	Fendiline and other calcium-channel blockers	Cardiovascular use	Not part of the phenylalkylamine subgroup

Verapamil is a small-molecule L-type calcium-channel blocker with additional effects on atrioventricular-node conduction. It is marketed in immediate-release tablets, sustained-release tablets, extended-release capsules, and injectable formulations. Product availability differs by country.

The ATC classification does not determine patent scope. Patent rights attach to a specific active ingredient, salt, polymorph, formulation, dosage regimen, manufacturing process, or method of use.

What is the FDA regulatory status of verapamil?

Verapamil has long-standing FDA approval in multiple dosage forms. The principal regulatory pathways are abbreviated new drug applications for generic products and older full new drug applications for branded formulations.

Product type	FDA status	Regulatory competition
Immediate-release verapamil tablets	Approved generic products	High
Sustained-release tablets	Approved generic products	High, but supplier count varies by strength
Extended-release capsules or tablets	Approved generic products in selected presentations	Moderate to high
Intravenous verapamil	Generic injectable products	Moderate
Brand extended-release products	Product-specific NDA approvals	Limited or discontinued depending on product

The FDA’s Orange Book identifies approved drug products and any patents or regulatory exclusivity submitted for listed reference products. For mature verapamil products, Orange Book-listed patents are generally not the principal commercial barrier. The relevant question is whether a specific extended-release product has residual formulation or delivery-system rights, not whether verapamil itself remains patented.[1]

What patents protect phenylalkylamine derivatives?

The original verapamil active-ingredient patent estate is expired in the United States and other major markets. Patent protection for current products is more likely to involve:

1. Extended-release dosage forms.
2. Controlled-release matrices.
3. Multiparticulate or pellet delivery systems.
4. Capsule or tablet coating technology.
5. Specific dosing schedules.
6. Manufacturing processes and impurity controls.
7. Combination products.
8. Narrow method-of-use claims.

Historical patents covering verapamil’s chemical structure and early pharmaceutical compositions no longer provide meaningful exclusion against ordinary generic verapamil products. Later patents may have protected particular release profiles or product architectures, but their value depends on claim construction and whether the generic product practices the claimed release mechanism.

Are active-ingredient patents still relevant?

For verapamil, generally no in the United States. The active ingredient has been commercially available for decades, and generic manufacturers can source or manufacture verapamil hydrochloride without confronting an unexpired compound patent in the major markets.

Gallopamil has a smaller commercial footprint. Its patent position is also mature, but the practical barrier to entry is more likely market size, regulatory economics, manufacturing availability, and clinical demand than enforceable composition-of-matter protection.

When did verapamil lose exclusivity?

Verapamil lost practical exclusivity decades ago. The timing differs by jurisdiction because approval dates, patent terms, supplementary protection certificates, data-exclusivity periods, and national filing histories vary.

Milestone	Commercial implication
Original verapamil compound and early formulation patents	Expired in major markets
Initial FDA approval of branded verapamil products	Followed by generic competition
ANDA approvals	Established broad generic substitution
Later extended-release products	Created narrower formulation-specific opportunities
Current market	Primarily generic and tender-driven

The United States does not have a single “verapamil patent expiration date” applicable to every product. Immediate-release tablets, extended-release tablets, capsules, and injectable products entered through different regulatory histories. Patent and exclusivity status must be assessed by reference product and dosage form in the current Orange Book.[1]

How many patents cover C08DA drugs?

No single patent count applies to ATC C08DA. ATC codes classify medicines therapeutically; they do not define a patent family or a searchable legal category.

A practical patent search should separate:

Patent category	Verapamil relevance	Current risk
Compound patents	Historical	Very low
Salt and crystalline-form patents	Limited	Low
Immediate-release composition patents	Historical	Very low
Extended-release formulations	Material for selected products	Low to moderate
Drug-delivery systems	Product-specific	Moderate where claims remain active
Method-of-use patents	Narrow and jurisdiction-specific	Low to moderate
Manufacturing patents	Supplier-specific	Moderate in regulated supply chains
Combination patents	Limited	Depends on product
Gallopamil-specific patents	Historical and limited	Low

Patent family counts can be inflated by continuation applications, national-stage filings, divisionals, and expired members. A useful freedom-to-operate analysis should count live, enforceable claim sets rather than raw publication numbers.

What formulations are protected by verapamil patents?

The strongest historical formulation opportunities involved sustained or controlled release. These products were developed to reduce dosing frequency and moderate plasma concentration changes.

Potentially relevant formulation features include:

• Hydrophilic or hydrophobic matrix systems.
• Coated pellets or granules.
• Osmotic or diffusion-controlled release.
• Multiparticulate capsules.
• Extended-release tablets.
• Specific dissolution profiles.
• Release over a defined period.
• Dose-proportional release behavior.
• Protection from dose dumping.
• Food-effect control.

A formulation patent is commercially meaningful only if the claims require a technical feature that a generic competitor cannot readily avoid. Claims limited to a target dissolution profile may create design-around risk if the competitor uses a different matrix, coating, particle architecture, or manufacturing process.

The commercial value of these patents has declined as formulation technologies became routine and as major verapamil brands faced generic competition. Remaining rights may still affect a particular product launch, but they are unlikely to recreate product-level exclusivity for the entire C08DA class.

Are there Paragraph IV challenges involving verapamil?

Paragraph IV litigation is associated with an ANDA applicant asserting that an Orange Book-listed patent is invalid, unenforceable, or not infringed. Mature verapamil products have historically been exposed to this type of challenge where branded extended-release products carried listed formulation patents.

Current risk is concentrated in product-specific extended-release listings. Immediate-release verapamil presents a lower Paragraph IV barrier because the relevant active ingredient and basic dosage form are long genericized.

Product segment	Paragraph IV exposure	Likely outcome profile
Immediate-release tablets	Low	Generic entry already established
Sustained-release tablets	Low to moderate	Depends on listed patents and dosage strength
Extended-release capsules	Moderate	Formulation and release-profile analysis required
Injectable products	Low to moderate	Manufacturing and supply qualification may matter more
New combination or repurposed products	Potentially higher	Depends on new-use claims

A patent challenge can still generate a 30-month stay if statutory requirements are met, but the commercial impact is usually limited for a mature product with multiple generic suppliers. The first ANDA filer may obtain 180-day exclusivity where the statutory conditions apply, although the value of that exclusivity depends on market size and the number of competing approvals.

What is the Orange Book status of verapamil?

The Orange Book status is product-specific rather than class-wide. It should be reviewed by searching each reference listed drug, dosage form, strength, and route.

The relevant Orange Book fields include:

• Reference listed drug designation.
• Approved dosage form and strength.
• Patent listing.
• Patent-use code.
• Regulatory exclusivity.
• First generic approval history.
• Therapeutic-equivalence rating.
• Discontinued or withdrawn status.

For mature verapamil products, the central Orange Book issue is whether any unexpired patents remain listed against a particular extended-release product. A generic applicant may avoid a listed method-of-use patent through a section viii statement if the proposed label omits the patented use. Formulation patents generally require a Paragraph IV certification if they are listed and relevant to the proposed product.[1]

What patent litigation affects phenylalkylamine derivatives?

The class has limited current litigation intensity compared with newer cardiovascular products. Historical disputes have generally involved:

• Validity of sustained-release formulation claims.
• Infringement by generic tablets or capsules.
• Patent-listing eligibility.
• Method-of-use carve-outs.
• ANDA filing procedures.
• Product-specific release characteristics.

There is no class-wide litigation mechanism. A dispute involving one verapamil extended-release brand does not automatically affect immediate-release tablets, injectable verapamil, or gallopamil.

Litigation exposure should be ranked by product:

1. Branded extended-release products with listed patents.
2. Products relying on proprietary release profiles.
3. Products with limited generic substitution.
4. Injectable presentations requiring specialized manufacturing.
5. Standard immediate-release tablets.

Which companies are challenging or competing with C08DA products?

Competition is fragmented. Verapamil is supplied by generic manufacturers, hospital injectable suppliers, and regional pharmaceutical companies. The identity of active suppliers changes by country, dosage form, and procurement contract.

The competitive landscape has four segments:

Segment	Competitive basis
Generic oral tablets	Price, regulatory approval, wholesaler access
Extended-release products	Bioequivalence, formulation performance, substitution status
Injectable verapamil	Sterile manufacturing, reliability, hospital contracts
Regional brands	Distribution, physician familiarity, national reimbursement

Large multinational generic companies may maintain approvals without continuous commercial supply. Smaller companies often compete through specific strengths, niche markets, or contract manufacturing. A list of approved applicants is not equivalent to a list of active commercial suppliers.

What are the market dynamics for C08DA drugs?

Verapamil is a mature, low-growth market. Demand is driven by established clinical use rather than new diagnosis expansion.

Key market characteristics include:

• High generic penetration.
• Low average selling prices for standard oral forms.
• Price competition among multiple suppliers.
• Stable demand in cardiology and hospital channels.
• Product-specific shortages when sterile or extended-release supply is disrupted.
• Limited investment in new verapamil indications.
• Modest commercial value for expired oral formulations.
• Greater relative value in reliable manufacturing and distribution.

Brand revenue exposure is concentrated in residual branded extended-release products and regional markets where generic substitution is incomplete. Public companies generally do not report C08DA revenue as a separate segment. Verapamil sales are usually aggregated into broader cardiovascular or generic-pharmaceutical revenue disclosures.

Revenue risk for an incumbent brand is highest where:

• The product has few approved substitutes.
• The dosage form is difficult to reproduce.
• Reimbursement favors the branded product.
• The product has a narrow therapeutic or hospital-use niche.
• Supply interruptions affect competing generics.

What generic launch scenarios exist for verapamil?

Immediate-release generic launch

This is the lowest-risk scenario from a patent perspective. The entrant typically relies on an ANDA demonstrating bioequivalence to the reference product. Commercial success depends on approval timing, manufacturing cost, wholesaler access, and supply reliability.

Extended-release generic launch

This scenario has greater technical and legal complexity. The applicant must match the reference product’s release characteristics and may need to address formulation patents. Design-around strategies can include different excipients, matrix systems, coating methods, or release-control mechanisms.

Injectable generic launch

The active ingredient is not the main barrier. Sterile manufacturing, container-closure systems, stability, extractables, and regulatory inspection history can determine entry speed and commercial viability.

Gallopamil re-entry

A gallopamil launch would face limited compound-patent risk but substantial commercial risk. The applicant would need to justify demand, secure a reliable active pharmaceutical ingredient source, and establish a viable regulatory and reimbursement position.

Is there biosimilar risk for ATC C08DA drugs?

There is no conventional biosimilar risk. Verapamil and gallopamil are chemically synthesized small molecules, not biologics. The applicable competitors are generic products, not biosimilars.

This distinction affects:

• Regulatory pathway.
• Bioequivalence requirements.
• Interchangeability analysis.
• Manufacturing economics.
• Patent litigation strategy.
• Substitution at the pharmacy level.

The relevant U.S. pathway is generally an ANDA under section 505(j) of the Federal Food, Drug, and Cosmetic Act, not a 351(k) biosimilar application.[2]

How strong is the patent estate for phenylalkylamine derivatives?

The class-level patent estate is weak because the principal active ingredient is old and genericized. Product-level patent strength varies.

Factor	Assessment
Compound protection	Exhausted
Basic oral dosage-form protection	Exhausted or commercially ineffective
Extended-release formulation protection	Product-specific and potentially meaningful
Method-of-use protection	Narrow, often avoidable through labeling
Manufacturing protection	Possible, but rarely blocks all supply
Geographic exclusivity	Uneven across countries
Litigation leverage	Limited for standard products
Commercial durability	Dependent on formulation and supply execution

The strongest remaining barrier is usually regulatory and technical rather than chemical. A supplier that controls a difficult-to-reproduce release system, qualified sterile process, or dependable API source may retain commercial advantage even without broad patent protection.

How does C08DA compare with newer cardiovascular drug classes?

Attribute	C08DA phenylalkylamines	Newer cardiovascular classes
Principal product	Verapamil	Often multiple patented agents
Compound-patent status	Generally expired	Frequently active during launch period
Generic competition	Extensive	Limited before loss of exclusivity
Biosimilar exposure	None	Relevant only for biologic products
Formulation value	Moderate for extended release	Can be high for modified delivery
Price erosion	Substantial	Lower before generic entry
Litigation intensity	Low to moderate	Often high around launch
Market growth	Mature	May be driven by new indications

C08DA products compete less through patent-backed differentiation and more through price, availability, clinical familiarity, and dosage-form performance.

What geographic patent coverage applies to C08DA products?

Patent protection is country-specific. The practical status is generally similar across major markets for verapamil’s core chemistry, but formulation and use patents may differ.

Region	Core verapamil patent posture	Main entry issue
United States	Core rights expired; product-specific Orange Book review required	Formulation patents and ANDA timing
European Union	Core rights expired	National validation and local product status
Japan	Mature generic market	Local approval and formulation requirements
China	Core chemistry mature	Local patent filings, registration, and procurement
India	Generic supply base	Process, formulation, and local enforcement
Latin America	Broad generic availability	National registration and reimbursement
Emerging markets	Variable	Supply, registration, and local manufacturing

A global launch assessment must review live patent families, national phase status, supplementary protection certificates, local regulatory exclusivities, and government procurement rules. A U.S. Orange Book clearance does not establish freedom to operate in Europe, China, India, or Latin America.

What manufacturing and intellectual-property barriers remain?

The primary barriers are operational:

• GMP-compliant API sourcing.
• Control of impurities and degradation products.
• Reproducible extended-release performance.
• Bioequivalence under fed and fasted conditions.
• Sterile injectable manufacturing.
• Stability across climatic zones.
• Qualified packaging components.
• Pharmacovigilance and supply continuity.
• Local registration and tender qualification.

Process patents can affect a specific API route, but they rarely prevent all entry if alternative synthesis routes are available. Formulation know-how may be more valuable than a narrow patent because it affects approval reliability, batch consistency, and product performance.

Key Takeaways

• ATC C08DA is centered on verapamil, with gallopamil as a limited secondary product.
• Verapamil’s core compound protection is expired in major markets.
• The remaining patent risk is concentrated in extended-release formulations, delivery systems, manufacturing processes, and narrow methods of use.
• FDA Orange Book analysis must be performed by reference product, dosage form, strength, and route.
• Paragraph IV risk is materially higher for selected extended-release products than for immediate-release tablets.
• C08DA products face generic competition, not biosimilar competition.
• Market value is low for standard oral products and relatively higher for reliable injectable supply and technically differentiated extended-release formulations.
• Geographic freedom to operate cannot be inferred from U.S. patent status.
• Manufacturing reliability, bioequivalence, procurement access, and supply continuity are often more important than residual patent protection.

FAQs About C08DA Phenylalkylamine Derivatives

What is the main drug in ATC C08DA?

Verapamil is the principal drug in ATC C08DA. It is used for hypertension, angina, and supraventricular tachyarrhythmias.

Is verapamil still patent protected?

The original verapamil compound protection has expired in major markets. Specific extended-release formulations or methods of use may have had later patent rights, subject to current national status.

Can a generic manufacturer launch immediate-release verapamil?

Yes, subject to applicable regulatory approval, quality requirements, and any product-specific unexpired rights. Immediate-release verapamil is a mature generic market.

Does verapamil have biosimilars?

No. Verapamil is a chemically synthesized small molecule. Competing products are regulated as generics rather than biosimilars.

What is the biggest commercial risk in launching a verapamil generic?

For ordinary tablets, the largest risks are price competition, limited market size, and supply economics. For extended-release or injectable products, formulation performance, sterile manufacturing, bioequivalence, and reliable supply are more significant.

References

1. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
2. U.S. Food and Drug Administration. (2024). Abbreviated new drug application (ANDA) process.
3. World Health Organization Collaborating Centre for Drug Statistics Methodology. (2024). ATC/DDD index: C08DA phenylalkylamine derivatives.
4. U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drugs.