List of Excipients in Branded Drug ESTAZOLAM

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Generic Drugs Containing ESTAZOLAM

Company	Ingredient	NDC	Excipient
Actavis Pharma Inc	estazolam	0591-0744	CELLULOSE, MICROCRYSTALLINE
Actavis Pharma Inc	estazolam	0591-0744	DOCUSATE SODIUM
Actavis Pharma Inc	estazolam	0591-0744	LACTOSE MONOHYDRATE
Actavis Pharma Inc	estazolam	0591-0744	MAGNESIUM STEARATE
Actavis Pharma Inc	estazolam	0591-0744	SODIUM BENZOATE
Actavis Pharma Inc	estazolam	0591-0744	SODIUM STARCH GLYCOLATE TYPE A POTATO
Actavis Pharma Inc	estazolam	0591-0744	STEARIC ACID

What are the Most Frequently-Used Excipients in ESTAZOLAM?

# Of NDCs	Excipient
1	ALUMINUM OXIDE
1	ANHYDROUS LACTOSE
2	CELLULOSE, MICROCRYSTALLINE
2	DOCUSATE SODIUM
1	FD&C RED NO. 40
6	LACTOSE MONOHYDRATE
3	MAGNESIUM STEARATE

Estazolam Excipient Strategy and Commercial Opportunities

Last updated: September 1, 2026

Estazolam is an established benzodiazepine hypnotic with limited remaining molecule-level exclusivity and a mature generic market. Commercial opportunity is therefore concentrated in formulation execution: reliable low-dose content uniformity, rapid tablet disintegration, improved swallowability, differentiated packaging, and geographic supply coverage. The principal constraints are controlled-substance regulation, generic price pressure, dependence and withdrawal warnings, and the limited clinical value of incremental formulation changes.

What is estazolam and how is it regulated?

Estazolam is an oral benzodiazepine indicated for the short-term management of insomnia characterized by difficulty falling asleep, frequent nighttime awakenings, or early-morning awakening. U.S. tablets are generally available in 1 mg and 2 mg strengths. The drug acts through the benzodiazepine site on the GABA-A receptor complex and produces sedative, hypnotic, anxiolytic, muscle-relaxant, and anticonvulsant effects [1].

The FDA-approved product is a tablet administered at bedtime. The U.S. prescribing information recommends 1 mg for many patients, with 2 mg considered when clinically appropriate. Elderly and debilitated patients generally require lower exposure because of increased sensitivity and slower clearance [1].

Estazolam is a Schedule IV controlled substance under the U.S. Controlled Substances Act. The regulatory status affects manufacturing controls, distribution, inventory management, prescribing, refills, serialization, and diversion monitoring [2].

FDA regulatory status

Attribute	Estazolam
Active ingredient	Estazolam
Drug class	Benzodiazepine hypnotic
Dosage form	Immediate-release oral tablet
Common strengths	1 mg and 2 mg
Original U.S. product	ProSom
FDA pathway for generics	Abbreviated New Drug Application
Controlled-substance schedule	Schedule IV
Primary indication	Short-term treatment of insomnia
Key safety issues	CNS depression, impairment, dependence, withdrawal, complex sleep behaviors
Biosimilar pathway	Not applicable

The FDA labeling includes boxed-warning language for benzodiazepine risks, including abuse, misuse, addiction, physical dependence, and withdrawal reactions. Co-administration with opioids can result in profound sedation, respiratory depression, coma, and death [1].

What excipients are used in estazolam tablets?

Public product labeling identifies conventional tablet excipients, but the exact composition can vary by manufacturer, strength, market, and manufacturing site. Commercially relevant estazolam excipient systems normally use a direct-compression or wet-granulation platform built around a diluent, disintegrant, lubricant, and, where needed, a glidant.

Typical candidate excipient classes include:

Functional role	Candidate excipients	Commercial purpose
Diluent	Lactose monohydrate, microcrystalline cellulose, mannitol, dibasic calcium phosphate	Tablet mass, compressibility, dose uniformity
Disintegrant	Croscarmellose sodium, crospovidone, sodium starch glycolate	Rapid breakup after administration
Binder	Povidone, pregelatinized starch, hydroxypropyl cellulose	Granule and tablet strength
Lubricant	Magnesium stearate, sodium stearyl fumarate	Ejection from tablet tooling
Glidant	Colloidal silicon dioxide	Powder flow and die filling
Flavor or mouthfeel modifier	Mannitol, selected polyols	Swallowability and patient acceptability
Colorant	Approved pigments or lakes	Strength differentiation and identification
Film coating	Hypromellose, polyethylene glycol, titanium dioxide or approved alternatives	Appearance, handling, swallowing, light protection

The innovator and generic labels should be reviewed separately because an excipient listed for one manufacturer is not necessarily present in another product. DailyMed provides current manufacturer-specific labeling, including inactive ingredients and strength-specific formulation details [3].

Which excipient properties matter most for estazolam?

The critical formulation issue is the low active dose relative to total tablet mass. A 1 mg tablet requires strong control of blend homogeneity, segregation, sampling, and compression behavior. Small changes in particle size, density, moisture, or lubrication can affect content uniformity and dissolution.

A robust excipient strategy should prioritize:

1. Uniform distribution of estazolam throughout the blend or granulate.
2. Rapid and reproducible disintegration.
3. Adequate mechanical strength without excessive compression force.
4. Low friability during packaging and distribution.
5. Consistent dissolution across 1 mg and 2 mg strengths.
6. Compatibility with high-throughput tablet manufacturing.
7. Color or imprint differentiation that reduces dispensing errors.

Estazolam is administered at low doses, making dose proportionality and manufacturing scale-up more important than maximizing tablet loading. A formulation with a larger but more uniform tablet may have stronger commercial and quality advantages than a smaller tablet with marginal blend performance.

What formulation patents could protect estazolam products?

The original estazolam molecule is old, and core compound protection is not expected to provide a meaningful current U.S. exclusivity barrier. Commercially relevant protection would instead need to focus on a specific formulation, manufacturing process, delivery system, or use.

Potential patentable areas include:

• Rapid-disintegration tablets with defined dissolution performance.
• Orally disintegrating tablets or sublingual delivery systems.
• Taste-masked multiparticulates.
• Modified-release or biphasic bedtime formulations.
• Abuse-deterrent dosage forms.
• Improved solid-state forms or particle-size specifications.
• Coated particles that control release or reduce direct contact with the active ingredient.
• Manufacturing processes that improve content uniformity at the 1 mg strength.
• Packaging systems that reduce moisture or light exposure.
• Combination products, although these would raise substantial clinical and regulatory issues.

A formulation patent must claim a technically meaningful composition or process, not merely the use of a common excipient with estazolam. Broad claims covering lactose, microcrystalline cellulose, magnesium stearate, or standard film coating would face substantial novelty and obviousness risk because these excipients are routine in oral solid dosage forms.

How strong is the current estazolam patent estate?

The current estazolam patent estate is likely weak at the active-ingredient level because the drug was approved decades ago and generic products are established. A sponsor seeking differentiated protection would need a narrow, data-supported formulation claim.

The strongest potential claims would tie the excipient system to measurable performance, such as:

• A specified disintegration time at defined compression conditions.
• A dissolution profile that reduces food or dose-related variability.
• Improved content uniformity at commercial scale.
• A stability advantage under accelerated conditions.
• A clinically meaningful pharmacokinetic profile for modified release.
• Reduced abuse potential supported by laboratory and clinical data.

Any patent analysis should review the current FDA Orange Book, USPTO Patent Center, WIPO PATENTSCOPE, and national patent registers. The Orange Book is the principal U.S. source for patents and regulatory exclusivity associated with approved drug products [4].

When does estazolam lose exclusivity?

Estazolam’s original regulatory exclusivity has expired. Generic competition is therefore permitted in the United States, subject to FDA approval requirements and controlled-substance manufacturing and distribution obligations.

The practical exclusivity position is:

Protection category	Current commercial relevance
Original compound patent	Expected to be expired
Original FDA marketing exclusivity	Expired
U.S. generic entry	Permitted through approved ANDAs
Orange Book-listed formulation patent	Must be verified in the current edition
Method-of-use exclusivity	No broad current exclusivity expected
Biosimilar exclusivity	Not applicable
New formulation exclusivity	Possible only for a newly approved product meeting statutory requirements

A new estazolam formulation could potentially qualify for regulatory exclusivity if it contains a clinically distinct formulation or delivery system and receives approval under an appropriate pathway. The commercial value would depend on whether the product delivers a benefit that physicians, pharmacies, payers, and patients recognize as superior to low-cost immediate-release tablets.

Are there Paragraph IV challenges to estazolam?

Paragraph IV litigation is most relevant when an ANDA applicant certifies that a listed patent is invalid, unenforceable, or not infringed. Because estazolam is an old genericized product, the probability of active high-value Paragraph IV litigation is lower than for recently approved products.

The applicable review points are:

• Whether any estazolam patents appear in the current Orange Book.
• Whether any listed patent has an unexpired term.
• Whether an ANDA applicant has filed a Paragraph IV certification.
• Whether the reference-listed drug has an active 30-month litigation stay.
• Whether a settlement agreement has been filed with the Federal Trade Commission.

No broad, current Paragraph IV risk should be assumed without checking the current Orange Book and FDA approval records. Patent litigation involving an old immediate-release estazolam tablet would generally require a specific unexpired patent claim directed to formulation, process, or use.

What formulation opportunities exist for estazolam?

Immediate-release tablets

This is the lowest-risk development route. A sponsor can use a conventional ANDA strategy if the product matches the reference listed drug in dosage form, strength, route, and performance. The commercial challenge is price competition.

Value-adding opportunities include:

• Better tablet hardness and lower friability.
• More reliable 1 mg content uniformity.
• Smaller tablet dimensions.
• Improved debossing and strength color coding.
• Moisture-resistant blister packaging.
• Consistent dissolution across manufacturing sites.
• Lactose-free or low-allergen positioning where commercially relevant.

These changes may improve manufacturing economics but may not justify a premium price unless they solve a visible pharmacy or patient problem.

Orally disintegrating tablets

An orally disintegrating estazolam tablet could target patients who have difficulty swallowing conventional tablets. The principal development risks include taste, dose uniformity, tablet friability, packaging moisture protection, and the potential for unintended rapid exposure.

A sponsor would need to establish that the product meets the FDA definition and performance expectations for an orally disintegrating tablet. If the dosage form changes material pharmacokinetic or safety characteristics, a 505(b)(2) pathway may be more appropriate than an ANDA [5].

Modified-release formulations

Modified release could extend sleep maintenance while reducing early-morning residual effects. This is scientifically attractive but commercially difficult. The product would require pharmacokinetic and clinical evidence addressing:

• Time to onset.
• Overnight exposure.
• Next-day psychomotor impairment.
• Elderly pharmacokinetics.
• Food effects.
• Dose titration.
• Accumulation and withdrawal.
• Comparative efficacy against immediate-release estazolam.

The risk-benefit profile of prolonging benzodiazepine exposure is a central barrier. A modified-release product would likely require a new clinical and regulatory strategy rather than a simple generic substitution.

Abuse-deterrent formulations

An abuse-deterrent estazolam product could use physical or chemical barriers, but the commercial case is uncertain. Benzodiazepines are misused orally, in combination with opioids, and through other routes. An abuse-deterrent claim would require evidence under FDA guidance and would not eliminate the risk of addiction, dependence, overdose, or co-use with other depressants [6].

The formulation could be protected through patents covering matrix composition, particle coating, resistance to crushing, or extraction behavior. Development costs would be high relative to the size of the estazolam market.

What manufacturing and IP barriers affect estazolam?

The active ingredient is commercially mature, so the main manufacturing barriers are operational rather than fundamental discovery barriers.

API and analytical controls

Important controls include:

• API identity, assay, impurities, and residual solvents.
• Particle-size distribution.
• Polymorphic or solid-state characterization.
• Blend uniformity at low dose.
• Dissolution and degradation-product monitoring.
• Segregation during transfer and compression.
• Cleaning validation for a potent controlled substance.

A supplier with validated low-dose blending and robust analytical methods can reduce batch failures and improve supply reliability. API source qualification is important because controlled-substance manufacturing requires additional chain-of-custody and inventory controls.

Packaging and distribution

Blister packaging can reduce tablet loss, improve unit-dose control, and limit moisture exposure. Bottles may be lower cost but create greater exposure to handling, counting, and diversion risks. Child-resistant packaging and label differentiation are routine but commercially important.

A branded generic could compete through pharmacy-friendly packaging, reliable fill rates, and consistent supply rather than through a major clinical claim.

Which companies are positioned to challenge estazolam products?

The competitive field consists primarily of generic manufacturers and contract development and manufacturing organizations with capabilities in controlled-substance oral solid dosage forms. The relevant competitive factors are:

• FDA-approved manufacturing capacity.
• Access to qualified estazolam API.
• ANDA status.
• Controlled-substance quotas and distribution licenses.
• Retail, institutional, and mail-order distribution.
• Ability to support multiple strengths.
• Product liability and pharmacovigilance systems.
• Supply continuity during manufacturing disruptions.

A current company-by-company ranking requires live FDA approval, shortage, and commercial data. Product listings in Drugs@FDA, DailyMed, and the FDA Orange Book provide the most reliable regulatory baseline [3,4,7].

What licensing deals could create value?

Licensing opportunities are more likely to involve formulation technology or geographic commercialization than the estazolam molecule itself.

Potential structures include:

Opportunity	Likely deal logic
Regional generic license	Local registration and distribution in markets with limited supply
Formulation license	ODT, modified release, or taste-masked technology
API supply agreement	Qualified source with controlled-substance capability
Manufacturing license	Transfer to a site with spare tablet capacity
Hospital or institutional supply	Contracted supply for insomnia treatment settings
Co-branded generic	Packaging, distribution, and pharmacy-channel differentiation

A license based only on rights to ordinary immediate-release estazolam tablets is unlikely to command significant value unless it includes a regulated market with limited competition or a reliable API and manufacturing platform.

What generic launch risks exist for estazolam?

Generic launch risk is moderate from a regulatory perspective and high from a commercial perspective.

The principal risks are:

1. A crowded market with limited price differentiation.
2. Low prescription growth for benzodiazepine hypnotics.
3. Controlled-substance compliance costs.
4. Safety scrutiny involving dependence, misuse, falls, and next-day impairment.
5. Payer substitution toward other hypnotics.
6. Physician preference for nonbenzodiazepine sleep products or behavioral therapy.
7. Limited willingness to pay for conventional excipient changes.
8. Potential product liability exposure.
9. API supply interruptions.
10. Inventory restrictions and quota management.

Revenue exposure is difficult to quantify without current prescription, net-sales, and market-share data. The opportunity should be modeled using product-level prescription volume, average selling price, expected generic erosion, channel mix, and the number of approved competitors.

How does estazolam compare with competing insomnia drugs?

Product class	Examples	Formulation opportunity	Commercial pressure
Benzodiazepine hypnotics	Estazolam, temazepam, triazolam	ODT, modified release, packaging	Safety and dependence concerns
Nonbenzodiazepine hypnotics	Zolpidem, zaleplon, eszopiclone	Immediate and modified release	Larger generic competition
Melatonin receptor agonist	Ramelteon	Extended release, combination approaches	Lower abuse potential
Orexin antagonists	Suvorexant, lemborexant, daridorexant	New dosage forms and combinations	Higher branded price, newer patents
Sedating antidepressants	Doxepin and others	Low-dose controlled release	Off-label and payer substitution
OTC sleep products	Diphenhydramine, doxylamine	Gummies, liquids, combination products	Consumer availability

Estazolam’s potential advantage is established hypnotic efficacy and conventional tablet manufacturing. Its disadvantages are controlled-substance status, dependence risk, next-day impairment concerns, and limited differentiation from other generic sedative-hypnotics.

Key Takeaways

• Estazolam is a mature, genericized benzodiazepine hypnotic with expired original exclusivity.
• The strongest commercial opportunities are excipient and manufacturing improvements, not new molecule protection.
• Low-dose content uniformity is the central technical issue, especially for 1 mg tablets.
• Immediate-release generic development is the lowest-risk pathway but faces severe price competition.
• Orally disintegrating and modified-release products could create differentiation but may require a 505(b)(2) strategy and new clinical evidence.
• Abuse-deterrent development has high technical and regulatory cost relative to the likely market size.
• Current Orange Book listings, ANDA approvals, patent records, and commercial data must determine live litigation and revenue exposure.
• Geographic licensing, API supply, controlled-substance manufacturing, and reliable distribution may offer more value than ordinary formulation patents.

FAQs

Can lactose-free estazolam tablets create a meaningful market advantage?

They can address lactose intolerance or formulation preferences, but the commercial advantage is likely limited unless the product has clear labeling, reliable supply, and distribution access. Lactose-free status alone would not normally support substantial premium pricing.

Could an estazolam liquid formulation be commercially viable?

A liquid could help patients who cannot swallow tablets, but it would create stability, dosing accuracy, taste, packaging, and controlled-substance diversion issues. It would likely require a formulation-specific regulatory strategy rather than a routine tablet ANDA.

Is an estazolam combination with melatonin patentable?

A combination could be patentable only if it satisfies novelty, non-obviousness, enablement, and other statutory requirements. Clinical evidence would likely be necessary to establish that the combination provides a meaningful therapeutic benefit over either component alone.

Would an estazolam transdermal patch have commercial value?

A patch could provide sustained exposure, but it would face permeability, dose delivery, adhesion, residual impairment, abuse, and clinical-development barriers. The prolonged exposure profile may create safety concerns inconsistent with the intended short-term hypnotic use.

Can a generic manufacturer claim a premium for improved packaging?

A premium is possible in institutional or controlled-distribution channels if packaging reduces dispensing errors, improves unit-dose handling, or supports diversion controls. In retail generics, packaging improvements alone rarely overcome payer-driven price competition.

References

1. U.S. Food and Drug Administration. (2023). Estazolam tablets: U.S. prescribing information. FDA-approved labeling.

2. U.S. Drug Enforcement Administration. (2024). Controlled substance schedules. U.S. Department of Justice.

3. National Library of Medicine. (2024). DailyMed: Estazolam product labeling. U.S. National Library of Medicine.

4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

5. U.S. Food and Drug Administration. (2022). ANDA submissions: Content and format of abbreviated new drug applications. FDA.

6. U.S. Food and Drug Administration. (2015). Assessment of abuse deterrence of opioid analgesics: Guidance for industry. FDA.

7. U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drug database. FDA.