List of Excipients in Branded Drug LISINOPRIL AND HYDROCHLOROTHIAZIDE

Generic Drugs Containing LISINOPRIL AND HYDROCHLOROTHIAZIDE

Company	Ingredient	NDC	Excipient
Eon Labs Inc	lisinopril and hydrochlorothiazide	0185-7100	ANHYDROUS DIBASIC CALCIUM PHOSPHATE
Eon Labs Inc	lisinopril and hydrochlorothiazide	0185-7100	CROSPOVIDONE
Eon Labs Inc	lisinopril and hydrochlorothiazide	0185-7100	FERRIC OXIDE RED
Eon Labs Inc	lisinopril and hydrochlorothiazide	0185-7100	FERRIC OXIDE YELLOW
Eon Labs Inc	lisinopril and hydrochlorothiazide	0185-7100	MAGNESIUM STEARATE

What are the Most Frequently-Used Excipients in LISINOPRIL AND HYDROCHLOROTHIAZIDE?

# Of NDCs	Excipient
1	ALUMINA
23	ALUMINUM OXIDE
77	ANHYDROUS DIBASIC CALCIUM PHOSPHATE
1	ANHYDROUS LACTOSE
6	CALCIUM PHOSPHATE, DIBASIC, ANHYDROUS

Lisinopril and Hydrochlorothiazide Excipient Strategy and Commercial Opportunities

Last updated: August 14, 2026

Lisinopril/hydrochlorothiazide is a mature immediate-release fixed-dose combination with limited composition-of-matter protection and substantial generic competition. Commercial value is concentrated in manufacturing efficiency, bioequivalence execution, differentiated excipient selection, supply reliability, and market access rather than in new-chemical-entity exclusivity.

The principal formulation opportunity is a robust, low-cost tablet platform that supports multiple strengths, avoids unnecessary excipient complexity, controls moisture exposure, and meets dissolution requirements for both active ingredients. Potential differentiation includes lactose-free or low-allergen formulations, reduced tablet burden, improved handling of lisinopril’s moisture sensitivity, and regional products aligned with local excipient preferences.

What is the commercial status of lisinopril/hydrochlorothiazide?

Lisinopril/hydrochlorothiazide combines an angiotensin-converting enzyme inhibitor with a thiazide diuretic. It is used for hypertension when monotherapy with either component does not provide adequate blood-pressure control.

The original branded product, Zestoretic, was developed by Merck. The product is now commercially dominated by generic manufacturers. FDA-approved strengths have historically included:

Strength	Lisinopril	Hydrochlorothiazide	Typical commercial role
Low dose	10 mg	12.5 mg	Initial combination or lower-intensity therapy
Intermediate dose	20 mg	12.5 mg	Common maintenance strength
High diuretic dose	20 mg	25 mg	Patients requiring greater diuretic effect

Product availability varies by manufacturer and market. The FDA-approved label for Zestoretic identifies these strengths and describes the product as an oral tablet fixed-dose combination (FDA, 2016).

The market is mature, price-sensitive, and generally substitutable. Competitive advantage depends on product availability, wholesale acquisition cost, payer contracts, manufacturing yield, and the ability to avoid supply interruptions.

What excipients are used in lisinopril/hydrochlorothiazide tablets?

The branded product label identifies excipients including calcium phosphate, mannitol, iron oxide, magnesium stearate, starch, and talc, although exact composition can vary by strength and manufacturer (FDA, 2016).

Generic formulations may use different excipient systems if they meet quality, safety, dissolution, stability, and bioequivalence requirements. Common excipient categories include:

Excipient function	Candidate materials	Formulation purpose
Diluent	Mannitol, microcrystalline cellulose, calcium phosphate, lactose	Controls tablet weight and compressibility
Binder	Povidone, pregelatinized starch, hydroxypropyl cellulose	Improves granule and tablet strength
Disintegrant	Crospovidone, croscarmellose sodium, sodium starch glycolate	Promotes tablet breakup and dissolution
Lubricant	Magnesium stearate, sodium stearyl fumarate	Reduces ejection force and sticking
Glidant	Colloidal silicon dioxide, talc	Improves powder flow
Colorant	Iron oxides, approved lakes	Supports strength identification and brand differentiation
Film coating	Hypromellose, polyethylene glycol, titanium dioxide, iron oxides	Improves handling, appearance, and swallowability

The formulation must account for the different physical and chemical properties of the two active pharmaceutical ingredients. Lisinopril is a polar, water-soluble compound that can create blend-uniformity and moisture-management challenges. Hydrochlorothiazide has lower aqueous solubility and can control dissolution performance. The formulation therefore requires a balanced approach to disintegration, wetting, particle-size distribution, and compression.

Which excipient strategy is most suitable for generic development?

A direct-compression platform is commercially attractive when both active ingredients have suitable particle characteristics and the blend can achieve acceptable content uniformity. It reduces unit operations and can lower cost, but it requires tight control of segregation, density differences, and low-dose hydrochlorothiazide distribution.

Wet granulation can improve blend uniformity and tablet robustness. It also introduces additional processing variables, including granulation endpoint, drying temperature, residual moisture, and granule-size distribution. For lisinopril/hydrochlorothiazide, a granulation process may be preferable where direct compression produces dissolution or content-uniformity failures.

A practical development strategy is:

1. Screen direct compression with mannitol, microcrystalline cellulose, or calcium phosphate.
2. Compare crospovidone and croscarmellose sodium for rapid disintegration.
3. Evaluate low-level magnesium stearate or sodium stearyl fumarate to limit over-lubrication.
4. Assess moisture-protective packaging early.
5. Use separate preblends or engineered granules if hydrochlorothiazide segregation occurs.
6. Confirm discriminatory dissolution methods for both active ingredients.

Excipient selection should be driven by the critical quality attributes of the final product rather than by matching the branded product’s inactive ingredients. FDA permits formulation differences in ANDA products when the product meets applicable regulatory requirements and demonstrates pharmaceutical equivalence and bioequivalence.

What formulation patents could protect lisinopril/hydrochlorothiazide?

New composition-of-matter protection is not the primary opportunity for this product. Lisinopril and hydrochlorothiazide are longstanding active ingredients, and the original branded combination has been subject to generic competition for many years.

Potential formulation patent themes include:

• Specific excipient ratios.
• Moisture-stabilized lisinopril compositions.
• Improved dissolution systems for hydrochlorothiazide.
• Granulation methods that reduce segregation.
• Film-coating systems that improve stability.
• Multilayer tablets or segregated active-containing regions.
• Orally disintegrating or modified-release dosage forms.
• Packaging systems that reduce hydrolysis or moisture uptake.
• Process controls linked to content uniformity or dissolution.

These claims face a high obviousness risk because the active ingredients, tablet dosage form, and major excipient classes are well known. A commercially meaningful patent should be tied to a measurable technical effect, such as a demonstrated stability improvement, a difficult-to-reproduce dissolution profile, or a manufacturing advantage that is not predictable from routine formulation work.

The strongest protection would usually combine composition claims with process and product-by-process claims. Broad claims covering ordinary tablets with conventional excipients are more vulnerable to invalidity challenges.

When does lisinopril/hydrochlorothiazide lose exclusivity?

The product has already passed its primary small-molecule exclusivity period. There is no biosimilar pathway because lisinopril/hydrochlorothiazide is a small-molecule drug, not a biologic.

Current market entry is generally governed by:

• ANDA approval under section 505(j) of the Federal Food, Drug, and Cosmetic Act.
• Patent certifications under section 505(j)(2)(A)(vii).
• Any remaining Orange Book-listed patents.
• State substitution rules and therapeutic-equivalence designations.
• Manufacturer-specific supply and distribution agreements.

Because the product is mature, commercial entry risk is more likely to involve regulatory deficiencies, manufacturing capacity, supply-chain interruptions, or pricing pressure than a fundamental exclusivity barrier.

What is the Orange Book status of lisinopril/hydrochlorothiazide?

The FDA Orange Book is the controlling source for current patent listings, exclusivity information, and therapeutic-equivalence evaluations. Historical brand patents and expired exclusivity should not be treated as current barriers without checking the current Orange Book entry and associated FDA approval records (FDA, n.d.-a).

For a prospective entrant, the required review should cover:

Review item	Commercial relevance
Reference listed drug	Establishes the ANDA reference product
Active ingredient and strength	Determines product-specific bioequivalence scope
Dosage form	Confirms tablet or other approved presentation
Patent listing status	Determines certification and launch timing
Exclusivity status	Identifies any remaining regulatory block
Therapeutic equivalence code	Affects pharmacy substitution and market access
Discontinued-product status	Can affect reference-product strategy

No biosimilar litigation framework applies. A generic applicant would use the ANDA pathway rather than a 351(k) application.

Which companies are challenging or competing with the branded product?

Competition comes primarily from generic manufacturers, including large U.S. and international suppliers with established antihypertensive portfolios. The relevant competitive set includes:

• Lisinopril/hydrochlorothiazide fixed-dose tablets.
• Separate lisinopril and hydrochlorothiazide prescriptions.
• Other ACE inhibitor/thiazide combinations, such as enalapril/hydrochlorothiazide.
• Angiotensin receptor blocker/thiazide products, such as losartan/hydrochlorothiazide.
• Calcium-channel-blocker combinations.
• Single-agent lisinopril and hydrochlorothiazide products.

The strongest commercial competitors are manufacturers with FDA-approved products, reliable active-ingredient sourcing, multiple tablet strengths, and established wholesaler relationships. A new entrant with no cost advantage would face limited pricing power.

What are the main commercial opportunities?

Low-cost multi-strength platform

The most direct opportunity is a single formulation platform supporting 10/12.5 mg, 20/12.5 mg, and 20/25 mg strengths. Common excipients across strengths can reduce procurement complexity and validation costs.

A shared platform should preserve:

• Similar compression behavior.
• Predictable dissolution across strengths.
• Simple color-coding.
• Common packaging components.
• Consistent analytical methods.

Lactose-free and excipient-sensitive products

A lactose-free product can address patients with lactose intolerance, excipient preferences, or institutional procurement requirements. This is a modest differentiation strategy, not a major clinical advantage. The commercial benefit depends on whether the product can maintain cost parity and obtain broad formulary coverage.

Moisture-protective packaging

Packaging can provide a practical product advantage where the formulation is sensitive to humidity. Options include high-barrier blister packs, desiccant-containing bottles, and optimized induction seals. Packaging claims alone are unlikely to create durable exclusivity, but they can improve shelf life, reduce complaints, and support distribution into humid markets.

Global-market excipient localization

Different markets impose different expectations on excipient acceptability, labeling, colorants, and allergen declarations. A manufacturer can develop region-specific versions using the same active-product platform while changing colorants, coating systems, or lactose content.

Contract manufacturing and private-label supply

Lisinopril/hydrochlorothiazide is suitable for contract manufacturing because the product has standardized strengths and predictable demand. Opportunities include:

• Private-label pharmacy products.
• Government tenders.
• Hospital and institutional supply.
• Regional distributor brands.
• Dual-source supply agreements.
• Portfolio bundling with lisinopril, hydrochlorothiazide, and other cardiovascular products.

What generic launch risks exist?

The primary risks are commercial and operational.

Risk	Impact
Price compression	Reduces gross margin after multiple generic entrants
Failure to demonstrate bioequivalence	Delays ANDA approval
Dissolution mismatch	Can trigger reformulation or additional regulatory work
Content-uniformity failure	Particularly relevant to low-dose hydrochlorothiazide
API supply disruption	Can interrupt product availability
Moisture-related degradation	Reduces shelf life or causes stability failures
Tablet sticking or capping	Raises manufacturing scrap
Excessive excipient complexity	Increases sourcing and regulatory burden
Weak wholesaler access	Limits prescription volume
Tender concentration	Creates dependency on a small number of contracts

Lisinopril/hydrochlorothiazide has limited tolerance for high-cost manufacturing. A formulation that requires multiple granulation steps, specialized equipment, or expensive excipients may not be commercially viable unless it produces a clear regulatory or supply advantage.

How strong is the patent estate for lisinopril/hydrochlorothiazide?

The legacy patent estate is commercially weak for a new entrant because the active ingredients and conventional immediate-release combination are mature. Any remaining value would likely reside in narrow formulation, process, packaging, or delivery-system claims rather than broad protection of the basic combination.

Patent strength should be assessed against five factors:

1. Claim breadth.
2. Remaining patent term.
3. Demonstrated technical effect.
4. Design-around feasibility.
5. Likelihood of Paragraph IV challenge.

A patent covering a conventional tablet with common excipients is vulnerable to an obviousness challenge. A patent linked to an unexpected stability or dissolution result has greater defensive value, but its commercial reach may be narrower.

What patent litigation and Paragraph IV exposure should be expected?

A new ANDA applicant must evaluate current Orange Book listings and certify against each applicable patent. A Paragraph IV certification alleges that a listed patent is invalid, unenforceable, or would not be infringed. The reference-product sponsor may file litigation, potentially triggering a 30-month stay under the Hatch-Waxman framework, subject to statutory conditions (FDA, n.d.-b).

For this mature combination, expected litigation exposure is generally lower than for recently launched branded drugs. The risk increases if a new branded product obtains approval for:

• A novel controlled-release profile.
• A patented multilayer tablet.
• A new indication.
• A proprietary dose ratio.
• A clinically differentiated delivery system.

A conventional generic immediate-release product is more likely to face ordinary ANDA review and commercial price competition than extensive patent litigation.

Are there licensing opportunities?

Licensing opportunities are more likely to involve manufacturing, regional commercialization, or product portfolios than core intellectual property.

Potential structures include:

• Territory-specific commercialization licenses.
• Contract manufacturing agreements.
• Authorized-generic arrangements.
• Co-marketing of cardiovascular products.
• Technology licenses for moisture-control packaging.
• Supply agreements for preformulated granules or coated tablets.

A license based only on the right to sell a standard lisinopril/hydrochlorothiazide tablet would have limited negotiating value unless it includes regulatory approvals, established market access, or protected geographic rights.

How does lisinopril/hydrochlorothiazide compare with newer antihypertensive combinations?

Product category	Patent strength	Price environment	Formulation opportunity
Lisinopril/hydrochlorothiazide	Low for basic combination	Highly competitive	Cost, stability, excipient differentiation
Losartan/hydrochlorothiazide	Generally mature	Competitive	Broad generic portfolio and global supply
Enalapril/hydrochlorothiazide	Mature	Competitive	Limited, mostly manufacturing-based
ARB/calcium-channel-blocker products	Varies by product	Higher for newer products	More opportunity in fixed-dose delivery
Branded triple antihypertensive products	Product-dependent	Potentially higher	Combination-device and adherence strategies

Lisinopril/hydrochlorothiazide has a lower commercial ceiling than newer branded combinations but also has lower development risk. The product can fit a high-volume, low-margin strategy where manufacturing scale and reliable supply are more important than premium pricing.

What FDA and quality requirements apply to excipient development?

FDA expects the finished product to meet applicable identity, strength, quality, purity, and performance requirements. Excipient changes can affect bioequivalence, dissolution, stability, content uniformity, and manufacturing controls.

Relevant development frameworks include:

• FDA ANDA product-specific guidance, where available.
• FDA Inactive Ingredient Database.
• USP-NF monographs.
• ICH Q8 for pharmaceutical development.
• ICH Q9 for quality-risk management.
• ICH Q10 for pharmaceutical quality systems.
• FDA process validation guidance.

The formulation team should establish critical material attributes for both active ingredients and excipients. Key variables include particle size, bulk density, moisture content, lubricant level, granule size, compression force, and coating weight gain.

Key Takeaways

• Lisinopril/hydrochlorothiazide is a mature generic fixed-dose combination with limited exclusivity value.
• The strongest commercial strategy is a low-cost, multi-strength immediate-release tablet platform.
• Excipient selection should focus on content uniformity, dissolution, moisture control, compressibility, and supply continuity.
• Mannitol, calcium phosphate, microcrystalline cellulose, starch, crospovidone, croscarmellose sodium, and magnesium stearate are commercially relevant formulation options.
• Lactose-free formulations and moisture-protective packaging offer practical but limited differentiation.
• Patent opportunities are narrow and should rely on demonstrable technical effects rather than conventional excipient combinations.
• Biosimilar risk does not apply; generic entry proceeds through the ANDA pathway.
• Paragraph IV litigation risk is generally lower than for recently approved branded products, but current Orange Book listings must control the legal analysis.
• Licensing value is most likely to arise from manufacturing capacity, geographic access, regulatory approvals, or supply agreements.
• Revenue exposure should be modeled using volume, price erosion, gross margin, wholesaler access, and supply reliability rather than brand-level exclusivity.

FAQs

Can lisinopril/hydrochlorothiazide be developed as an orally disintegrating tablet?

Yes, but the commercial rationale is limited unless the product demonstrates a meaningful swallowing or adherence benefit. The formulation must address taste, moisture sensitivity, mechanical strength, and rapid dissolution for both active ingredients.

Is a lactose-free lisinopril/hydrochlorothiazide tablet commercially valuable?

It can provide modest differentiation for excipient-sensitive patients and selected institutional customers. Its value depends on maintaining comparable cost, tablet performance, and market access.

Can a new excipient combination obtain a patent for this drug?

Yes, if the claims define a novel and non-obvious composition or process supported by a measurable technical effect. Conventional use of known fillers, binders, disintegrants, and lubricants is unlikely to provide strong protection.

What is the main bioequivalence challenge for this combination?

The key challenges are demonstrating comparable dissolution and consistent exposure for both lisinopril and hydrochlorothiazide while controlling blend uniformity, especially where hydrochlorothiazide is present at the lower dose.

Is separate co-packaging of lisinopril and hydrochlorothiazide a stronger commercial opportunity?

Usually not for cost-sensitive generic markets. A fixed-dose tablet reduces pill burden and can simplify dispensing. Separate products may be useful where dose flexibility, titration, or procurement requirements outweigh adherence benefits.

References

1. U.S. Food and Drug Administration. (2016). Zestoretic: Lisinopril and hydrochlorothiazide tablets prescribing information.
2. U.S. Food and Drug Administration. (n.d.-a). Approved drug products with therapeutic equivalence evaluations, Orange Book.
3. U.S. Food and Drug Administration. (n.d.-b). Hatch-Waxman amendments and abbreviated new drug applications.
4. U.S. Food and Drug Administration. (n.d.-c). Inactive ingredient database.
5. International Council for Harmonisation. (2009). ICH Q8(R2): Pharmaceutical development.
6. International Council for Harmonisation. (2005). ICH Q9: Quality risk management.
7. International Council for Harmonisation. (2008). ICH Q10: Pharmaceutical quality system.
8. United States Pharmacopeial Convention. (2024). United States Pharmacopeia and National Formulary.