List of Excipients in Branded Drug HYDROCHLOROTHIAZIDE

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Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Actavis Pharma Inc	HYDROCHLOROTHIAZIDE	hydrochlorothiazide	0591-0347	D&C RED NO. 28
Actavis Pharma Inc	HYDROCHLOROTHIAZIDE	hydrochlorothiazide	0591-0347	D&C YELLOW NO. 10
Actavis Pharma Inc	HYDROCHLOROTHIAZIDE	hydrochlorothiazide	0591-0347	FD&C BLUE NO. 1
Actavis Pharma Inc	HYDROCHLOROTHIAZIDE	hydrochlorothiazide	0591-0347	FD&C BLUE NO. 2

Generic Drugs Containing HYDROCHLOROTHIAZIDE

Company	Ingredient	NDC	Excipient
Actavis Pharma Inc	hydrochlorothiazide	0228-2820	CALCIUM STEARATE
Actavis Pharma Inc	hydrochlorothiazide	0228-2820	FD&C YELLOW NO. 6
Actavis Pharma Inc	hydrochlorothiazide	0228-2820	LACTOSE MONOHYDRATE
Actavis Pharma Inc	hydrochlorothiazide	0228-2820	SODIUM LAURYL SULFATE

What are the Most Frequently-Used Excipients in HYDROCHLOROTHIAZIDE?

# Of NDCs	Excipient
1	AKA3
20	ALCOHOL
5	ALUMINUM OXIDE
19	AMMONIA

Hydrochlorothiazide Excipient Strategy and Commercial Opportunities

Last updated: September 30, 2026

Hydrochlorothiazide (HCTZ) is an established, low-cost generic diuretic with limited standalone patent value and substantial formulation opportunity. Commercial differentiation depends on excipient performance, dosage-form convenience, fixed-dose combinations, supply reliability, and market-specific regulatory execution rather than molecule-level exclusivity.

HCTZ is approved for hypertension and edema and is marketed mainly as an immediate-release oral tablet, both alone and in combination with antihypertensive agents. The active ingredient has no meaningful remaining primary patent barrier in the United States. The strongest opportunities are pediatric and geriatric dosage forms, low-dose content uniformity, combination products, preservative-free liquids, and robust global supply platforms.

What patents protect hydrochlorothiazide products?

Hydrochlorothiazide has no commercially significant active composition-of-matter patent estate. Its original patent protection expired decades ago, and generic manufacturers compete primarily through abbreviated new drug applications, manufacturing scale, price, and product quality.

What is the Orange Book status of hydrochlorothiazide?

FDA-approved HCTZ products are listed in the Orange Book through multiple approved applications and combination products. The Orange Book identifies approved drug products, therapeutic equivalence evaluations, patent information where applicable, and exclusivity data. HCTZ products generally have no current regulatory exclusivity that prevents ANDA competition [1].

Exclusivity or patent category	HCTZ commercial position
Composition-of-matter patent	Expired
Basic formulation patent	No meaningful active estate generally associated with standalone HCTZ
New chemical entity exclusivity	Expired
Orphan exclusivity	Not applicable
Biologic exclusivity	Not applicable
Pediatric exclusivity	Not generally associated with current standalone HCTZ products
ANDA pathway	Available for qualifying products
Paragraph IV risk	Generally low for standalone HCTZ; relevant only if an applicant targets an active listed patent for a specific product

A Paragraph IV certification is unlikely to create a major barrier for conventional HCTZ tablets because the molecule and basic dosage form are long established. Risk can arise in a branded combination, a recently approved liquid, a novel delivery system, or a product with active formulation or method-of-use claims.

When does hydrochlorothiazide lose exclusivity?

Hydrochlorothiazide lost practical market exclusivity long before the modern generic market. It is now a mature generic active pharmaceutical ingredient with extensive regulatory precedent.

The principal commercial protection has shifted from patent exclusivity to execution:

1. Reliable API procurement.
2. Low-cost tablet manufacturing.
3. Consistent dissolution and content uniformity.
4. FDA-compliant stability data.
5. Differentiated dosage forms.
6. Combination-product development.
7. Supply continuity during shortages.

FDA labeling identifies HCTZ as an orally active thiazide diuretic. It is used alone or with other antihypertensive drugs, and its therapeutic role is established in hypertension and edema management [2].

How many patents cover hydrochlorothiazide formulations?

The number of historical HCTZ-related patents is substantial, but the relevant question is whether enforceable claims remain for a target product. For conventional immediate-release HCTZ tablets, the active patent barrier is effectively absent.

Potentially relevant patent categories include:

Patent category	Commercial relevance
HCTZ compound patents	Expired
Tablet formulation patents	Mostly expired or commercially weak for conventional products
Modified-release systems	Could be relevant if a new product is developed and patented
Liquid formulations	May support patents or regulatory exclusivity if technically novel
Fixed-dose combinations	Claims may cover composition, ratio, process, or use
Manufacturing processes	Can protect a specific process but rarely prevents all generic entry
Polymorph or particle-size claims	Potentially relevant if they produce a measurable performance advantage
Taste-masking systems	Relevant for pediatric or orally disintegrating products
Method-of-use claims	May matter for specific indications or dosing regimens

A company seeking defensible protection would need to claim a measurable technical result, such as improved suspension stability, dissolution under defined conditions, reduced dose variability, enhanced palatability, or improved compatibility with another active ingredient.

What excipients are used in hydrochlorothiazide tablets?

Conventional HCTZ tablets typically use a compact excipient system designed for low-dose uniformity, mechanical strength, rapid disintegration, and acceptable dissolution.

Common excipient classes include:

Excipient class	Typical function in HCTZ products
Lactose or microcrystalline cellulose	Diluent and compression support
Pregelatinized starch or maize starch	Binder and disintegrant
Povidone	Wet or dry binder
Croscarmellose sodium or sodium starch glycolate	Superdisintegrant
Colloidal silicon dioxide	Glidant
Magnesium stearate or sodium stearyl fumarate	Lubricant
Film-coating polymers	Appearance, swallowability, protection, and product identification
Titanium dioxide or iron oxides	Opacity and color, subject to jurisdictional requirements
Sweeteners and flavors	Palatability in liquid and chewable products
Suspending agents	Physical stability in oral suspensions

The excipient choice must support HCTZ content uniformity because the drug is commonly dosed at 12.5 mg, 25 mg, or 50 mg. Low-dose tablets are especially sensitive to segregation, poor powder flow, over-lubrication, and nonuniform API distribution.

What excipient strategy is best for hydrochlorothiazide tablets?

The strongest baseline strategy is a direct-compression or dry-granulation platform using a robust diluent-disintegrant system and a controlled lubrication process.

Direct compression

Direct compression can reduce processing steps, equipment requirements, and manufacturing cost. It is suitable when the API and excipients provide adequate flow, blend uniformity, and compactability.

Key development controls include:

• API particle-size distribution.
• Blend segregation during transfer.
• Sampling-plan sensitivity.
• Tablet weight variation.
• Compression-force range.
• Disintegration time.
• Dissolution after accelerated stability.
• Magnesium stearate mixing time.

Direct compression is commercially attractive for high-volume generic tablets, but it requires strong control of low-dose blend uniformity.

Wet granulation

Wet granulation can improve flow, reduce segregation, and increase tablet robustness. It may be preferable when HCTZ has poor flow or when a combination product contains APIs with incompatible compression behavior.

The main disadvantages are higher manufacturing cost, increased process complexity, and potential stability concerns from water exposure. Aqueous granulation should be evaluated against API and excipient stability data rather than selected as a default process.

Dry granulation

Roller compaction can improve flow without introducing water. It is useful for moisture-sensitive combinations or products requiring high-throughput manufacture. Excessive compaction can reduce tablet porosity and slow disintegration, so ribbon density and milling conditions require tight control.

What formulations are protected by hydrochlorothiazide excipient patents?

The most commercially defensible future formulations would combine HCTZ with a differentiated delivery or stability attribute. Conventional tablet claims are difficult to defend because prior art is extensive.

Potential formulation concepts include:

Pediatric oral liquids

HCTZ is used in pediatric and neonatal settings in some clinical contexts, but liquid availability and compounding practices vary by market. A ready-to-use suspension could reduce extemporaneous compounding and improve dose flexibility.

Excipient priorities include:

• Uniform suspension through the labeled shelf life.
• Low sedimentation and easy redispersion.
• Accurate dosing from oral syringes.
• Palatable taste.
• Microbial control.
• Low sugar or sugar-free composition.
• Compatibility with enteral feeding tubes.
• Minimal sorption to common dosing devices.

A liquid product would need a clear regulatory strategy because FDA-approved labeling, concentration, stability, preservative system, and device performance determine its commercial value.

Orally disintegrating tablets

An orally disintegrating HCTZ product could target patients with dysphagia, older adults, and care settings where water access is limited. The formulation challenge is balancing rapid disintegration with acceptable taste and low tablet friability.

Potential excipient tools include porous mannitol, crospovidone, low-substituted hydroxypropyl cellulose, flavor systems, and taste-masking coatings.

Chewable tablets

Chewable HCTZ may support pediatric dosing, but bitterness and dose accuracy are major barriers. A taste-masked multiparticulate system or polymer-coated API could have greater value than a simple compressed chewable tablet.

Fixed-dose combinations

HCTZ is already combined with agents such as losartan, valsartan, lisinopril, irbesartan, and triamterene. Combination products provide greater commercial opportunity than standalone HCTZ because they can improve adherence and reduce pill burden.

Excipient development must address:

• Different dose strengths.
• API compatibility.
• Dissolution of each component.
• Moisture sensitivity.
• Segregation caused by different particle sizes or densities.
• Separate release requirements.
• Stability-indicating analytical methods.

How does hydrochlorothiazide compare with other thiazide diuretics?

HCTZ competes with chlorthalidone and indapamide in hypertension, while also appearing in a large number of fixed-dose combinations.

Attribute	Hydrochlorothiazide	Chlorthalidone	Indapamide
Market maturity	Very high	High	High
Generic availability	Extensive	Extensive	Extensive
Typical commercial role	Standalone and combination products	Standalone hypertension therapy	Standalone hypertension therapy
Excipient opportunity	Liquids, ODTs, combinations	Similar, but lower product breadth	Similar, with formulation differentiation
Patent leverage	Minimal	Minimal for conventional products	Minimal for conventional products
Main competitive advantage	Physician familiarity, combination breadth, low cost	Longer duration of action	Low-dose efficacy and differentiated clinical positioning

HCTZ remains commercially relevant because it is embedded in established combination products and treatment protocols. Its low unit price limits standalone margin, but high prescription volume can support efficient manufacturing and private-label supply.

What generic entry risks exist for hydrochlorothiazide?

Generic entry risk is high because the product is mature, technically familiar, and inexpensive to manufacture. A new entrant should expect price competition in conventional 12.5 mg, 25 mg, and 50 mg tablets.

Risk is lower for products with:

• An approved pediatric indication.
• A ready-to-use liquid.
• A device-linked dosing system.
• A validated tube-feeding profile.
• A differentiated ODT or chewable format.
• A stable, low-cost fixed-dose combination.
• A documented shortage-resilience advantage.

The primary barriers are regulatory and operational rather than patent-based. They include bioequivalence where required, dissolution comparability, stability, facility compliance, API qualification, extractables and leachables for liquids, and supply-chain continuity.

What is the FDA regulatory status of hydrochlorothiazide?

HCTZ is an FDA-approved small-molecule drug. Generic products generally proceed through the ANDA pathway when they demonstrate pharmaceutical equivalence and bioequivalence to a reference-listed drug. Combination products may require additional comparative studies and product-specific regulatory analysis.

A reformulated HCTZ product may require a 505(b)(2) application when it relies in part on FDA findings for an approved product but introduces a new dosage form, route, formulation, concentration, or clinical use. The 505(b)(2) route may be relevant for:

• Ready-to-use oral suspensions.
• Novel pediatric concentrations.
• ODT products.
• New combination ratios.
• Modified-release products.
• Device-supported administration.

The pathway depends on the product’s formulation, reference product, labeling, and level of reliance on existing FDA findings [3].

Which companies are challenging hydrochlorothiazide products?

Competition is fragmented among generic manufacturers, contract development and manufacturing organizations, and suppliers of fixed-dose antihypertensive products. Major generic companies have historically marketed HCTZ alone or in combination with other cardiovascular agents.

Because HCTZ has no meaningful standalone patent moat, competitive positioning typically depends on:

• Cost of goods.
• Manufacturing location.
• API security.
• Approved strength portfolio.
• Supply reliability.
• Wholesaler and payer contracting.
• Private-label relationships.
• Combination-product breadth.

A company entering the market should avoid relying on a single low-margin tablet presentation. A portfolio approach is more defensible: conventional tablets for volume, a liquid or ODT for differentiation, and one or more fixed-dose combinations for margin and customer retention.

What licensing deals could create value around hydrochlorothiazide?

The most credible licensing opportunities are formulation and commercial, not molecule licensing. Potential transactions include:

1. Licensing a ready-to-use pediatric suspension.
2. Out-licensing an ODT or taste-masked platform.
3. Supplying HCTZ as part of a fixed-dose cardiovascular portfolio.
4. Contract manufacturing for hospital and institutional channels.
5. Regional licensing of approved combination products.
6. Co-development of low-cost products for emerging markets.
7. Licensing an excipient or device system that improves dosing accuracy.

A standalone HCTZ API license is unlikely to command material value unless it includes an integrated supply agreement, regulatory dossier, protected manufacturing process, or access to a differentiated finished product.

How strong is the hydrochlorothiazide patent estate?

The conventional HCTZ patent estate is weak. Patent strength is higher only where a sponsor develops a genuinely differentiated product with claims tied to measurable performance.

A stronger patent package could include:

• Composition claims covering a stable suspension.
• Use claims for a defined pediatric population.
• Device claims for dose administration.
• Process claims for improved content uniformity.
• Combination claims covering a novel ratio or release profile.
• Packaging claims linked to moisture or light protection.
• Formulation claims supported by comparative dissolution or stability data.

Patent value would still depend on claim breadth, freedom to operate, written-description support, enablement, and the ability to show commercial importance. A narrow excipient claim that can be designed around may offer little practical protection.

What revenue exposure exists in hydrochlorothiazide?

Standalone HCTZ has limited revenue potential because reimbursement and retail prices are low. Revenue exposure is more significant in combination products and institutional supply contracts.

The main commercial drivers are:

Revenue driver	Impact
High prescription volume	Supports scale but increases price pressure
Combination products	Improves retention and product value
Pediatric and geriatric formulations	Supports differentiation
Hospital supply contracts	Creates recurring volume
Shortage-resistant supply	Can improve procurement position
Global-market registrations	Expands volume but increases regulatory cost
Private-label manufacturing	Supports capacity utilization

For investors and licensors, the relevant metric is not HCTZ unit price alone. It is the combined value of the product portfolio, including other APIs, regulatory approvals, manufacturing utilization, and customer contracts.

What manufacturing and geographic barriers affect HCTZ?

Geographic patent barriers are limited for the active ingredient and standard tablet. Country-specific requirements remain important for registration, excipient acceptability, labeling, pharmacopoeial compliance, and local GMP inspections.

Manufacturing risks include:

• API concentration and blend uniformity.
• Nitrosamine and elemental impurity controls where applicable.
• Supplier qualification.
• Particle-size changes between API lots.
• Dissolution shifts caused by lubricant or granulation changes.
• Stability differences across climatic zones.
• Excipients that are accepted in one jurisdiction but restricted or less preferred in another.
• Limited backup capacity for low-margin products.

A global HCTZ strategy should use a platform formulation where possible, while allowing country-specific coating colors, packaging, excipient substitutions, and concentration requirements.

Key Takeaways

• HCTZ has no meaningful remaining standalone patent exclusivity.
• Conventional tablets are highly exposed to generic price competition.
• Excipient strategy should prioritize low-dose uniformity, fast disintegration, dissolution consistency, and manufacturing efficiency.
• Pediatric liquids, ODTs, chewables, and tube-compatible suspensions offer the clearest formulation opportunities.
• Fixed-dose combinations are commercially stronger than standalone HCTZ.
• A 505(b)(2) pathway may be relevant for novel dosage forms and concentrations.
• Patent value is limited unless claims cover a measurable technical advantage.
• Commercial value is driven by volume, supply reliability, combination-product breadth, and regulatory execution.
• Biosimilar risk is not applicable because HCTZ is a small-molecule drug, not a biologic.
• Licensing opportunities are concentrated in differentiated formulations, regional commercialization, and contract supply.

FAQs

Does hydrochlorothiazide have biosimilar competition?

No. HCTZ is a chemically synthesized small molecule. Competitors enter through generic drug pathways, principally ANDAs, rather than the biosimilar pathway.

Can an HCTZ oral suspension receive patent protection?

Yes. A suspension may support formulation, stability, device, process, or use claims if the claims are novel, non-obvious, enabled, and supported by comparative technical data. A routine suspension with conventional excipients is less likely to produce strong protection.

Is hydrochlorothiazide suitable for an orally disintegrating tablet?

Yes, but taste masking, low tablet strength, friability, dose uniformity, and rapid disintegration must be controlled. The commercial opportunity is greater where the product targets dysphagia, geriatric care, or pediatric administration.

Does HCTZ require a Paragraph IV certification?

Only when an ANDA applicant is addressing an active patent listed for the relevant reference product. Conventional standalone HCTZ products generally have limited active patent exposure, but each target product must be assessed against current FDA Orange Book listings.

What is the best commercial entry strategy for HCTZ?

A portfolio strategy is stronger than a conventional tablet launch alone. The most defensible approach combines a low-cost immediate-release tablet with a differentiated liquid, ODT, or fixed-dose combination and a reliable multi-region supply chain.

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/orange-book-data-files

2. U.S. Food and Drug Administration. (2023). Hydrochlorothiazide prescribing information. DailyMed. https://dailymed.nlm.nih.gov/

3. U.S. Food and Drug Administration. (2024). Applications covered by section 505(b)(2). https://www.fda.gov/drugs/development-approval-process-drugs/section-505b2-applications

4. U.S. Food and Drug Administration. (2024). Inactive Ingredient Database. https://www.accessdata.fda.gov/scripts/cder/iig/index.cfm

5. United States Pharmacopeial Convention. (2024). United States Pharmacopeia and National Formulary. USP.