List of Excipients in Branded Drug BUSPIRONE HYDROCHLORIDE

Generic Drugs Containing BUSPIRONE HYDROCHLORIDE

Company	Ingredient	NDC	Excipient
Teva Pharmaceuticals USA Inc	buspirone hydrochloride	0093-0053	ANHYDROUS LACTOSE
Teva Pharmaceuticals USA Inc	buspirone hydrochloride	0093-0053	CELLULOSE, MICROCRYSTALLINE
Teva Pharmaceuticals USA Inc	buspirone hydrochloride	0093-0053	MAGNESIUM STEARATE
Teva Pharmaceuticals USA Inc	buspirone hydrochloride	0093-0053	SILICON DIOXIDE

What are the Most Frequently-Used Excipients in BUSPIRONE HYDROCHLORIDE?

# Of NDCs	Excipient
157	ANHYDROUS LACTOSE
1	CARBOXYMETHYLCELLULOSE
256	CELLULOSE, MICROCRYSTALLINE
1	COLLOIDAL SILICON DIOXIDE

Buspirone Hydrochloride Excipient Strategy and Commercial Opportunities

Last updated: August 4, 2026

Buspirone hydrochloride is a mature, multisource anxiolytic with limited composition-of-matter protection and no biosimilar pathway. Commercial value is concentrated in differentiated oral formulations, dose-flexible products, adherence improvements, pediatric or geriatric presentations, and supply-chain reliability rather than in conventional generic tablets.

The strongest near-term strategy is a low-risk immediate-release tablet platform using a robust, low-cost excipient system. Higher-value opportunities include orally disintegrating tablets, sprinkle or multiparticulate products, and modified-release systems, although each requires clinical, bioequivalence, and food-effect development.

What is buspirone hydrochloride and how is it regulated?

Buspirone hydrochloride is the hydrochloride salt of buspirone, an azaspirodecanedione anxiolytic approved for the management of anxiety disorders. In the United States, it is marketed primarily as an immediate-release oral tablet in strengths including 5 mg, 7.5 mg, 10 mg, 15 mg, and 30 mg, with some strengths supplied as scored tablets or designed for dose splitting.[1]

Buspirone differs from benzodiazepines because it is not a controlled substance under the U.S. Controlled Substances Act and does not have the same sedative, muscle-relaxant, or dependence profile associated with benzodiazepines. Its clinical effect is delayed compared with acute sedative anxiolytics, which limits substitution in rapid-onset indications.

Attribute	Buspirone hydrochloride
Therapeutic class	Azaspirodecanedione anxiolytic
Primary dosage form	Immediate-release oral tablet
U.S. regulatory pathway	Abbreviated New Drug Application for generic products
Controlled-substance status	Not scheduled under the U.S. Controlled Substances Act
Common strengths	5, 7.5, 10, 15, and 30 mg
Administration	Usually divided into two or three daily doses
Primary metabolism	CYP3A4
Key formulation issue	Food effect and extensive first-pass metabolism
Biosimilar relevance	None; buspirone is a small molecule
Patent position	Core product protection is expired; current value is formulation- and execution-driven

The FDA label states that buspirone should be taken consistently with respect to food because food can increase systemic exposure.[1] This requirement is important for formulation design, labeling, bioequivalence, and patient adherence.

What excipients are used in buspirone hydrochloride tablets?

Commercial immediate-release buspirone tablets generally use conventional solid-dose excipients. Product-specific formulations vary by manufacturer, and the DailyMed label should be used to verify the current inactive-ingredient list for each marketed product.[2]

Typical excipient functions include:

Functional role	Suitable excipient families	Commercial rationale
Diluent	Lactose monohydrate, microcrystalline cellulose, dibasic calcium phosphate, mannitol	Controls tablet weight, compressibility, and cost
Binder	Povidone, copovidone, pregelatinized starch, hydroxypropyl cellulose	Improves granule and tablet strength
Disintegrant	Croscarmellose sodium, crospovidone, sodium starch glycolate	Supports rapid tablet breakup
Lubricant	Magnesium stearate, sodium stearyl fumarate	Reduces ejection force and tooling adhesion
Glidant	Colloidal silicon dioxide, talc	Improves powder flow
Film former	Hypromellose, polyvinyl alcohol	Provides identification, protection, and swallowability
Opacifier or colorant	Titanium dioxide, iron oxides, approved FD&C colors	Supports product differentiation and dose identification
Taste modifier	Sucralose, acesulfame potassium, flavor systems	Relevant to orally disintegrating or chewable formats

A conventional formulation should prioritize rapid and reproducible disintegration, low tablet weight, acceptable hardness, and chemical stability. Buspirone tablets are taken repeatedly each day, so tablet size, score performance, and visual strength differentiation have commercial importance.

Which excipient strategy is strongest for generic buspirone tablets?

The lowest-risk strategy is a direct-compression or dry-granulation platform with a neutral diluent, a high-efficiency disintegrant, and a low-level lubricant.

Recommended immediate-release platform

A practical development concept would use:

• Microcrystalline cellulose or a lactose-cellulose blend as the principal filler.
• Crospovidone or croscarmellose sodium as the primary disintegrant.
• Colloidal silicon dioxide to improve flow where needed.
• Magnesium stearate or sodium stearyl fumarate at the minimum level needed for manufacturability.
• Hypromellose or polyvinyl alcohol for film coating.
• A color-coding system that clearly separates 5 mg, 7.5 mg, 10 mg, 15 mg, and 30 mg strengths.

The selection should be driven by dissolution and tablet robustness rather than by excipient novelty. A generic product does not normally obtain meaningful market exclusivity merely by using a different conventional excipient.

Lactose versus microcrystalline cellulose

Lactose can reduce cost and provide good compaction in wet-granulated or direct-compression systems. Microcrystalline cellulose generally provides stronger compaction and faster wicking but can increase tablet bulk and create variability when moisture conditions change.

A lactose-cellulose hybrid can balance:

• Tablet hardness.
• Disintegration time.
• Powder flow.
• Compression speed.
• Tablet size.
• Supply availability.

The manufacturer should evaluate lactose intolerance labeling, aldehyde-related compatibility concerns, moisture exposure, and the API's impurity profile before selecting lactose as the primary diluent.

Crospovidone versus croscarmellose sodium

Crospovidone often provides rapid disintegration through wicking and remains useful in low-dose immediate-release tablets. Croscarmellose sodium provides strong swelling and can perform well at low concentrations, but excessive levels can affect tablet integrity or create variability after prolonged storage.

The final choice should be based on:

1. Dissolution across pH conditions.
2. Stability under accelerated humidity.
3. Tablet friability.
4. Compression-speed performance.
5. Sensitivity to lubricant concentration.
6. Release after score-line splitting.

What formulation patents could protect buspirone products?

Current commercial protection is unlikely to come from the original buspirone molecule. Original composition-of-matter and early product patents are expired or no longer commercially relevant in the U.S. market. The FDA Orange Book remains the primary source for checking current listed patents and regulatory exclusivities for approved products.[3]

Potentially protectable subject matter includes:

• Orally disintegrating buspirone tablets.
• Taste-masked buspirone particles.
• Multiparticulate capsules or sachets.
• Modified-release systems.
• Specific polymer matrices.
• Improved stability systems.
• Low-moisture formulations.
• Coated particles that control dissolution.
• Combination products with another anxiolytic or antidepressant.
• Defined methods of treating a patient subgroup.
• Manufacturing processes that produce a specific impurity profile or dissolution profile.

A formulation patent is stronger when it links the excipient system to a measurable technical result, such as a defined dissolution profile, improved chemical stability, reduced food effect, reduced dose variability, or improved bioavailability. A patent claiming only a broad list of conventional excipients is vulnerable to enablement, written-description, obviousness, and freedom-to-operate challenges.

When does buspirone hydrochloride lose exclusivity?

Buspirone hydrochloride has already lost conventional U.S. market exclusivity. Generic competition is established, and multiple manufacturers have marketed buspirone tablets through ANDAs.

Exclusivity category	Current position
Original molecule patent	Expired
New chemical entity exclusivity	Expired
Standard generic entry	Already available
Pediatric exclusivity	No current commercial significance for the mature product
Orphan exclusivity	Not applicable to the conventional anxiety indication
Biosimilar exclusivity	Not applicable
Potential new exclusivity	Possible only through a qualifying new formulation, method, or combination

A new buspirone product could obtain three-year FDA exclusivity for certain qualifying clinical investigations supporting a change in an approved product, but a reformulation does not automatically receive exclusivity. A new formulation also does not automatically receive patent protection.

What is the Orange Book status of buspirone hydrochloride?

The Orange Book identifies FDA-approved products, therapeutic-equivalence information, listed patents, and regulatory exclusivity data.[3] For a mature generic such as buspirone hydrochloride tablets, the relevant commercial conclusion is that the market is primarily an ANDA market rather than a market protected by active originator exclusivity.

The company should review:

• The reference listed drug designation.
• Therapeutic-equivalence codes.
• Any patent or exclusivity entries associated with the reference product.
• Strength-specific approval status.
• Manufacturing sites and applicant ownership.
• Discontinued or withdrawn products.
• Current FDA approval status for each intended strength.

An applicant should not assume that a patent-free market eliminates all risk. A new product can still encounter formulation patents, trademark issues, manufacturing patents, supplier restrictions, or litigation involving a differentiated dosage form.

Are Paragraph IV challenges relevant to buspirone?

Paragraph IV litigation is unlikely to be the central issue for conventional buspirone tablets because generic entry is already established. A Paragraph IV strategy becomes relevant if a company seeks to challenge a later-listed patent covering a reformulated buspirone product.

Potential Paragraph IV targets could include patents covering:

• Extended-release delivery.
• Orally disintegrating dosage forms.
• Taste-masked compositions.
• Specific particle-size distributions.
• Food-effect reduction.
• Combination therapy.
• A defined patient population or dosing regimen.

For a conventional ANDA, the main certification analysis remains Paragraph I, II, III, or IV depending on the Orange Book record and the status of listed patents. A Section viii statement could be relevant where a method-of-use patent is listed but the applicant intends to omit the protected indication from labeling.

What are the best commercial formulation opportunities for buspirone?

Orally disintegrating tablets

An orally disintegrating tablet could address patients who have difficulty swallowing conventional tablets. The principal technical risks are bitterness, friability, moisture sensitivity, and dose uniformity.

Useful excipient systems may include:

• Mannitol for mouthfeel and cooling sensation.
• Crospovidone for rapid breakup.
• Low-substituted hydroxypropyl cellulose for porosity.
• Colloidal silicon dioxide for flow.
• Sucralose or acesulfame potassium for sweetness.
• Flavor and taste-masking technologies.
• Moisture-protective blister packaging.

The product would need a clear clinical and commercial reason to exist because generic tablets are inexpensive and widely available.

Sprinkle or multiparticulate formulation

A sprinkle product could improve administration for patients who cannot swallow tablets. Multiparticulates can also support taste masking and flexible dosing.

The main risks are:

• Dose uniformity across a capsule or sachet.
• Stability of coated particles.
• Food interaction.
• Labeling regarding chewing or crushing.
• Manufacturing complexity.
• Higher cost than standard tablets.

Modified-release buspirone

Modified release could reduce the burden of twice- or three-times-daily administration. The opportunity is technically attractive but commercially uncertain because the product would need to demonstrate a meaningful pharmacokinetic or adherence benefit.

Buspirone's extensive first-pass metabolism and CYP3A4 dependence complicate release-rate design. A modified-release formulation could alter peak concentration, exposure, metabolite formation, and food sensitivity. It would require a full development program rather than a simple formulation substitution.

Pediatric or geriatric presentations

A low-dose liquid, dispersible tablet, or mini-tablet could target patients requiring flexible titration. The clinical and regulatory case depends on the intended indication, age group, dosing evidence, palatability, preservative strategy, and device accuracy.

Key excipient issues include:

• Preservative selection.
• Microbial control.
• Sedimentation and redispersibility.
• Sweetener and flavor acceptability.
• Alcohol and propylene glycol content.
• Container-closure compatibility.
• Dose-measuring-device accuracy.

Combination products

Buspirone combinations with antidepressants or other psychiatric medicines could improve convenience, but the regulatory and clinical burden is high. A fixed-dose combination would need evidence that the combination is appropriate for the target population and that each active ingredient contributes to the claimed effect.

How strong is the buspirone patent estate?

The conventional buspirone tablet patent estate is weak from a market-exclusivity perspective because the molecule and long-established immediate-release product are genericized. The stronger opportunities are narrow formulation claims tied to objective performance characteristics.

Patent category	Relative strength
Original buspirone molecule	Low; expired
Conventional immediate-release tablet	Low
Broad excipient combination	Low to moderate
Taste-masked ODT	Moderate if technically specific
Multiparticulate delivery	Moderate
Modified release	Moderate to high if clinically differentiated
Manufacturing impurity control	Moderate if difficult to reproduce
Method of use	Variable and indication-dependent
Packaging-only claims	Generally low

A formulation patent should be supported by comparative data against a conventional buspirone tablet. Useful evidence includes dissolution, pharmacokinetics, food-effect testing, stability, tablet performance, taste scores, and patient-use data.

What manufacturing and IP barriers affect buspirone products?

Buspirone is not generally viewed as a high-barrier active ingredient. The main barriers are executional:

• Reliable API sourcing.
• Control of polymorphic or solid-state properties.
• Impurity and degradant control.
• Consistent low-dose content uniformity.
• Compression performance.
• Moisture protection.
• Strength-specific tooling.
• Bioequivalence under fed and fasted conditions.
• Control of CYP3A4-related drug-interaction labeling.
• Supplier qualification for critical excipients.

The manufacturer should protect the product through a layered IP strategy covering composition, process, particle engineering, packaging, and clinically relevant performance. Trade secrets may be more valuable than patents for granulation parameters, coating conditions, blend order, compression settings, and impurity-control procedures.

Which companies are competing in buspirone hydrochloride?

Competition is primarily among generic pharmaceutical companies and contract manufacturers. The market is characterized by:

• Multiple ANDA holders.
• Price competition in standard strengths.
• Limited differentiation in conventional tablets.
• Periodic supply opportunities when manufacturers withdraw or experience shortages.
• Retail, mail-order, Medicaid, and institutional purchasing pressure.
• Low switching costs for pharmacies and payers.

A company entering the standard tablet market needs either a cost advantage, dependable supply, a preferred wholesaler position, or a differentiated dosage form. A second conventional generic without a supply or contracting advantage is unlikely to generate durable pricing power.

What is the revenue exposure and commercial outlook?

Publicly available sources do not provide a single reliable, product-level revenue figure for all buspirone hydrochloride manufacturers. Commercial exposure is best assessed through prescription volume, average selling price, payer mix, channel concentration, product availability, and strength-level market share.

The standard tablet opportunity is defensive rather than high-growth. Revenue can still be attractive where a manufacturer has:

• Low-cost domestic or regional production.
• Strong API supply.
• Multiple approved strengths.
• High service levels.
• Stable pharmacy and institutional contracts.
• A shortage-driven entry window.
• A differentiated ODT, liquid, or sprinkle product.

A differentiated product can command better pricing, but development and regulatory costs rise sharply. The optimal strategy is usually to establish a reliable immediate-release platform first, then evaluate a specialty formulation only if market research confirms an unmet administration or adherence problem.

How does buspirone compare with competing anxiolytic products?

Product category	Buspirone	Benzodiazepines	SSRIs or SNRIs
Controlled-substance issue	Generally no	Often yes	No
Onset	Delayed	Rapid	Delayed
Dependence concern	Lower than benzodiazepines	Material	Generally low
Dosing frequency	Often divided daily	Varies	Often once daily
Generic competition	High	High	High
Formulation opportunity	ODT, liquid, modified release	Abuse-deterrent and extended release	Extended release and combination products
Main commercial weakness	Delayed effect and limited differentiation	Dependence and safety concerns	Delayed onset and adverse-effect management

Buspirone's commercial position depends on its noncontrolled status and suitability for longer-term therapy. Those advantages do not automatically create pricing power because generic competition is extensive.

What generic launch scenarios exist for buspirone?

Scenario 1: Conventional tablet launch

This is the fastest and lowest-risk route. The product uses established excipients, conventional packaging, and standard ANDA development. Success depends on cost, supply continuity, and channel access.

Scenario 2: Full-strength portfolio launch

Launching 5 mg, 7.5 mg, 10 mg, 15 mg, and 30 mg strengths improves prescribing and pharmacy substitution coverage. The trade-off is higher tooling, stability, validation, and inventory complexity.

Scenario 3: ODT or liquid launch

This targets swallowing difficulty, flexible dosing, and selected institutional or specialty channels. It creates more defensible commercial positioning but requires taste, stability, and usability work.

Scenario 4: Modified-release launch

This has the highest potential differentiation and the highest development risk. The product must show clinically meaningful value, not merely a different dissolution curve.

Key Takeaways

• Buspirone hydrochloride is a mature generic small-molecule anxiolytic with no biosimilar pathway.
• Core molecule and conventional immediate-release tablet protection are expired or commercially weak.
• The best low-risk excipient strategy uses standard fillers, superdisintegrants, glidants, lubricants, and protective film coatings.
• The main formulation risks are food effect, first-pass metabolism, low-dose uniformity, bitterness, and repeated daily dosing.
• Orally disintegrating, liquid, sprinkle, and modified-release products offer the clearest differentiation opportunities.
• Conventional generic entry requires cost, supply, or contracting advantages because price competition is intense.
• Stronger formulation patents require objective performance data and narrowly defined technical features.
• Paragraph IV litigation is mainly relevant to later reformulated products, not the established conventional tablet market.
• Revenue opportunity is likely to be stable and execution-driven rather than based on broad product exclusivity.
• A staged strategy, beginning with a robust immediate-release portfolio and followed by targeted specialty formulations, offers the best risk-adjusted commercial path.

FAQs

Can buspirone hydrochloride be formulated as an oral solution?

Yes. An oral solution or suspension could support flexible dosing and patients unable to swallow tablets. Development must address solubility, pH, preservative efficacy, microbial control, taste, container compatibility, and dose-measuring accuracy.

Does buspirone hydrochloride require a special controlled-release excipient?

No for the standard product. Conventional buspirone tablets are immediate-release. A controlled-release product would require a separate formulation and regulatory strategy using polymers, coated multiparticulates, osmotic technology, or another release-control system.

Which excipients are most useful for a buspirone orally disintegrating tablet?

Mannitol, crospovidone, low-substituted hydroxypropyl cellulose, colloidal silicon dioxide, sweeteners, flavors, and taste-masking agents are common development candidates. The final system must balance rapid disintegration, palatability, hardness, and moisture stability.

Does buspirone hydrochloride have a biosimilar market?

No. Biosimilars apply to biological products. Buspirone hydrochloride is a chemically synthesized small molecule and is regulated through generic-drug pathways such as ANDAs in the United States.

Can a new buspirone formulation receive market exclusivity?

Potentially, but not automatically. A qualifying reformulation supported by required clinical investigations may receive limited FDA exclusivity, and a patent may protect a novel formulation or method. Conventional excipient substitution alone is unlikely to create durable exclusivity.

References

1. U.S. Food and Drug Administration. (2024). Buspirone hydrochloride tablets: Prescribing information. FDA-approved labeling.

2. National Library of Medicine. (2025). DailyMed: Buspirone hydrochloride tablet product labeling and inactive ingredients. U.S. National Library of Medicine.

3. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations. FDA Center for Drug Evaluation and Research.

4. U.S. Food and Drug Administration. (2019). Guidance for industry: ANDAs for certain highly purified synthetic peptides. FDA Center for Drug Evaluation and Research.

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