List of Excipients in Branded Drug STIOLTO RESPIMAT

STIOLTO RESPIMAT Excipient Strategy, Formulation Patents, and Commercial Opportunities

Last updated: August 9, 2026

STIOLTO RESPIMAT is a propellant-free, aqueous soft-mist inhalation product containing tiotropium bromide and olodaterol hydrochloride. Its commercial differentiation depends on the combination of active ingredients, the Respimat device, multidose cartridge, spray performance, and formulation stability rather than on a large excipient package. The principal excipients are benzalkonium chloride, edetate disodium, hydrochloric acid, and water for injection. The strongest commercial opportunities are in generic or authorized-generic device development, preservative-free reformulation, cartridge and valve engineering, regional manufacturing, and differentiated long-acting bronchodilator combinations.

What is STIOLTO RESPIMAT and how is it formulated?

STIOLTO RESPIMAT is a once-daily maintenance treatment for chronic obstructive pulmonary disease. It combines:

Component	Function	Label strength
Tiotropium bromide	Long-acting muscarinic antagonist	2.5 mcg per actuation
Olodaterol hydrochloride	Long-acting beta2-adrenergic agonist	2.5 mcg per actuation
Benzalkonium chloride	Preservative	Present
Edetate disodium	Chelating agent and preservative-support excipient	Present
Hydrochloric acid	pH adjustment	Present
Water for injection	Vehicle	Main liquid phase

The labeled dose is two inhalations once daily, providing a total daily dose of 5 mcg tiotropium and 5 mcg olodaterol. Each cartridge contains 60 metered actuations, equivalent to 30 daily doses. The product is administered through the Respimat inhaler, which generates a slow-moving aerosol from an aqueous solution without a hydrofluoroalkane propellant (Boehringer Ingelheim Pharmaceuticals, 2024).

The formulation is commercially important because the drug product is inseparable from the delivery system. A competitor must generally reproduce or sufficiently match the cartridge, metering system, nozzle, aerosol plume, emitted dose, fine-particle fraction, and patient-use characteristics.

What excipients are used in STIOLTO RESPIMAT?

Benzalkonium chloride

Benzalkonium chloride is the principal antimicrobial preservative in the formulation. Its use supports multidose packaging by reducing microbial growth risk after repeated inhaler use.

Commercial and technical constraints include:

• Potential local airway tolerability concerns in sensitive patients.
• Concentration control across the product shelf life.
• Interaction with container materials, elastomers, and device components.
• Need to demonstrate preservative effectiveness in the finished multidose system.
• Possible market demand for preservative-free alternatives.

Benzalkonium chloride can adsorb to surfaces or interact with other formulation components. The formulation developer must control its concentration, purity profile, and compatibility with the cartridge, closure, metering components, and nozzle.

Edetate disodium

Edetate disodium, also known as disodium edetate or EDTA disodium, chelates trace metal ions. Its functions may include improving chemical stability and supporting preservative performance by reducing metal-catalyzed degradation or microbial resistance mechanisms.

The commercial value of edetate disodium is greater than its low concentration might suggest. Trace metals introduced through raw materials, manufacturing equipment, or container components can affect the stability of inhaled solutions. A replacement formulation must assess whether EDTA is necessary, whether another chelator can be used, and whether removing it changes degradation pathways or preservative effectiveness.

Hydrochloric acid

Hydrochloric acid is used for pH adjustment. In an aqueous inhalation solution, pH affects:

• Active-ingredient solubility.
• Chemical degradation.
• Preservative activity.
• Osmolality and local tolerability.
• Compatibility with cartridge and device materials.
• Aerosol generation and emitted-dose consistency.

Hydrochloric acid is not normally the central patent differentiator. The commercially relevant issue is the target pH range and the formulation’s stability at that range.

Water for injection

Water for injection is the vehicle. Inhalation-grade water must meet applicable compendial and microbiological requirements. The formulation must maintain chemical, physical, and microbiological quality throughout manufacture, storage, and in-use handling.

Water quality, dissolved gases, extractables, and microbial control can affect the product even where the formulation contains a preservative. The cartridge and filling process must be qualified as part of the finished product.

How does the Respimat device affect excipient strategy?

The Respimat system uses mechanical energy to produce a soft mist from an aqueous solution. It does not depend on a propellant, lactose carrier, or capsule puncturing mechanism. That design creates a different excipient and development profile from dry-powder inhalers and pressurized metered-dose inhalers.

The formulation must be compatible with:

• Multidose cartridge storage.
• Metering chamber dimensions.
• Spring-driven or mechanically actuated aerosol generation.
• Nozzle geometry.
• Device priming and dose-counting behavior.
• Patient handling over approximately 30 days of once-daily use.
• Long-term contact with plastics, elastomers, adhesives, and metal components.

A change in excipient concentration can alter viscosity, surface tension, density, spray formation, and delivered dose. A competitor therefore cannot assume that a pharmaceutically equivalent solution will produce an equivalent aerosol.

Critical quality attributes

The key product attributes include:

Attribute	Commercial relevance
Delivered dose uniformity	Determines dose consistency across the cartridge
Aerodynamic particle-size distribution	Affects lung deposition
Fine-particle dose	Supports therapeutic delivery to the lower airways
Spray duration	Influences patient coordination and usability
Plume geometry	Affects inhalation technique and regional deposition
Droplet-size distribution	Links formulation and nozzle performance
Priming performance	Affects first-dose reliability
In-use stability	Determines performance after opening and repeated use
Container-closure integrity	Controls evaporation, contamination, and leakage

FDA guidance treats inhalation products as complex drug-device combinations because formulation, container, and delivery system jointly determine performance (FDA, 1998; FDA, 2018).

What formulation opportunities exist for STIOLTO RESPIMAT?

Preservative-free reformulation

The clearest excipient opportunity is a preservative-free version. Removing benzalkonium chloride could address tolerability concerns and create differentiation in markets where preservative exposure is commercially sensitive.

A preservative-free product would require an alternative microbial-control strategy, such as:

• A sterile single-use or limited-use cartridge.
• Improved container-closure integrity.
• A redesigned filling and assembly process.
• Reduced in-use duration.
• Alternative antimicrobial systems, subject to inhalation safety requirements.
• Device architecture that limits contamination during repeated use.

The opportunity is technically attractive but commercially difficult. A preservative-free formulation may require a new drug-device combination, new stability data, microbiological validation, and potentially a new regulatory pathway.

Alternative chelator systems

A competitor could evaluate replacement or removal of edetate disodium. Potential benefits include a smaller excipient profile, lower raw-material complexity, and opportunities for differentiated stability claims. The main barrier is proving that active-ingredient degradation, preservative performance, and aerosol delivery remain controlled without EDTA.

Osmolality and tolerability optimization

The formulation can be optimized for airway tolerability through adjustment of pH, ionic strength, and excipient concentration. A more physiologically acceptable formulation could support a product-positioning strategy for patients who report irritation or cough.

Claims based solely on improved tolerability require controlled clinical or postmarketing evidence. A formulation change without demonstrated clinical benefit would have limited commercial value.

Cartridge stability and extractables control

The cartridge is a major source of technical differentiation. Opportunities include:

• Low-sorption materials.
• Improved barrier properties.
• Reduced extractables and leachables.
• Better resistance to evaporation.
• Higher dimensional consistency.
• Longer in-use stability.
• More efficient filling and assembly.

These improvements can support device patents, manufacturing patents, supplier agreements, and regulatory differentiation even when the active ingredients and listed excipients remain unchanged.

What patents protect STIOLTO RESPIMAT?

Protection for STIOLTO RESPIMAT can arise from several patent categories:

Patent category	Protected subject matter	Commercial effect
Active-ingredient patents	Tiotropium, olodaterol, or related chemical forms	May be expired or separately relevant to the combination
Combination patents	Tiotropium plus olodaterol in COPD treatment	Can delay or complicate generic entry
Method-of-use patents	Once-daily treatment, dose regimen, or COPD population	Supports patent litigation and labeling restrictions
Formulation patents	Aqueous solution, pH, excipient system, concentration, or stability	May require design-around work
Device patents	Respimat mechanism, cartridge, nozzle, metering, and actuation	Can block device substitution
Manufacturing patents	Filling, assembly, sterilization, and quality-control processes	Raises manufacturing and scale-up barriers
Presentation patents	Cartridge and inhaler configuration	May support secondary protection

The FDA Orange Book lists approved-product patents and regulatory exclusivity associated with the U.S. product. For STIOLTO RESPIMAT, the relevant reference product is NDA 206756. Patent status must be assessed by matching each listed patent to its expiration date, pediatric extension, terminal disclaimer, litigation history, and any settlement restrictions (FDA, 2025a).

A patent covering the active combination does not automatically protect every formulation or device. Conversely, a device patent can remain commercially important after active-ingredient patents expire if the generic applicant must use a comparable inhaler system.

When does STIOLTO RESPIMAT lose exclusivity?

STIOLTO RESPIMAT has several distinct exclusivity dates rather than one universal loss-of-exclusivity date.

Regulatory exclusivity

The product received FDA approval in 2015. New chemical entity exclusivity generally lasts five years, but a fixed-dose combination containing previously approved active ingredients may not receive full NCE exclusivity for both components. Other regulatory protections can include pediatric exclusivity, clinical-investigation exclusivity, or orphan-drug exclusivity where applicable.

The practical generic-entry date is therefore determined by the combined effect of:

1. FDA regulatory exclusivity.
2. Listed patents.
3. Paragraph IV litigation.
4. Court-imposed stays.
5. Settlement terms.
6. Generic device readiness.
7. FDA approval of the abbreviated new drug application.

Patent expiry

Patent expiry depends on the specific patent family and any patent-term adjustment or extension. Combination, method-of-use, formulation, and device patents can expire on different dates. An ANDA applicant may challenge only selected patents, carve out a patented method of use, or wait for later patent expiration.

Pediatric extension

A six-month pediatric extension can apply to qualifying patents or regulatory exclusivity. The extension is patent-specific and should be reviewed in the Orange Book and underlying FDA records rather than applied automatically to every protection layer.

What Paragraph IV challenges and generic entry risks exist?

A generic applicant seeking approval before the latest relevant patent expiry may file a Paragraph IV certification alleging that a listed patent is invalid, unenforceable, or not infringed. The NDA holder can file suit within 45 days, triggering a statutory stay of FDA approval of up to 30 months under the Hatch-Waxman framework, subject to court action and litigation developments (FDA, 2025b).

For STIOLTO RESPIMAT, the highest-risk challenge areas are likely to be:

• Combination claims covering tiotropium and olodaterol.
• Once-daily COPD dosing claims.
• Aqueous formulation claims.
• Cartridge and device claims.
• Inhaler performance claims.
• Manufacturing claims that are difficult to avoid at commercial scale.

Generic entry can occur through several scenarios:

Entry scenario	Description	Risk to originator
Full-label ANDA approval	Generic matches the approved formulation and device profile	High
Skinny-label approval	Patented method of use is carved out	Moderate
Authorized generic	Originator or licensee supplies a lower-priced version	High commercial impact, lower litigation risk
Device-substitution product	Competitor uses a different inhaler with equivalent performance	Depends on FDA review and patent scope
505(b)(2) product	Uses selected reference-product data but introduces formulation or device changes	Moderate; may create separate patent value
Regional license	Local company commercializes under license	Reduces geographic competition but can lower price

How strong is the STIOLTO RESPIMAT patent estate?

The estate is strongest where formulation and device claims overlap with regulatory complexity. A patent that covers only a narrow pH range or an individual excipient concentration may be easier to design around. A patent that combines active-ingredient concentrations, aqueous vehicle characteristics, cartridge configuration, and aerosol performance is more difficult to avoid.

Strength indicators include:

• Multiple independent claim types.
• Claims covering both formulation and delivery system.
• Patent families with different priority dates.
• Claims that map directly to the approved commercial product.
• Manufacturing claims that are difficult to replicate without reverse engineering.
• Remaining patent term after FDA approval.
• Absence of successful invalidity decisions.
• Litigation settlements that delay competing entry.

Weakness indicators include:

• Broad prior art on tiotropium, olodaterol, and aqueous inhalation solutions.
• Narrow concentration or pH limitations.
• Publicly disclosed formulation composition.
• Device claims that can be avoided with a redesigned inhaler.
• Separate patents that expire before the principal commercial opportunity.
• Method-of-use claims that can be carved out of a generic label.

Patent strength should be evaluated claim by claim. The commercial question is whether a competitor can produce an approvable, scalable product without practicing the claims that remain enforceable.

What licensing deals and partnerships could create commercial value?

The most likely licensing opportunities involve delivery technology rather than the active ingredients alone. Potential structures include:

• Licensing a soft-mist inhaler platform.
• Contract manufacturing of cartridges.
• Regional commercialization rights.
• Authorized-generic supply arrangements.
• Co-development of preservative-free inhalation solutions.
• Acquisition of inhalation-device patents.
• Technology transfer for sterile filling and assembly.
• Supply agreements for specialized nozzles, cartridge materials, or valves.

A device owner can negotiate from a stronger position if its platform has regulatory precedent, validated aerosol performance, and manufacturing capacity. A formulation company can create leverage by offering a stable preservative-free solution that fits an existing device architecture.

How does STIOLTO RESPIMAT compare with competing COPD inhalers?

STIOLTO RESPIMAT competes with other long-acting muscarinic antagonist/long-acting beta2-agonist products, including umeclidinium/vilanterol, glycopyrrolate/formoterol, and aclidinium/formoterol combinations.

Product type	Formulation platform	Excipient strategy	Main barrier
STIOLTO RESPIMAT	Aqueous soft mist	Preserved solution with EDTA	Device and cartridge equivalence
Dry-powder LAMA/LABA	Powder carrier system	Often lactose-based or carrier-free	Powder engineering and inhaler design
Pressurized MDI LAMA/LABA	Propellant suspension or solution	HFA-compatible excipients	Propellant, valve, and spray performance
Other soft-mist products	Aqueous solution	Similar device-linked strategy	Device patents and aerosol matching

STIOLTO’s formulation has a relatively small excipient burden, but its device dependency increases development cost. A dry-powder competitor may avoid the Respimat device estate but face different bioequivalence and aerodynamic-performance requirements.

What FDA regulatory issues affect excipient opportunities?

FDA review will focus on both pharmaceutical equivalence and device performance. Relevant areas include:

• Identity and quantity of each active ingredient.
• Qualitative and quantitative excipient composition.
• Impurities and degradation products.
• Microbial quality and preservative effectiveness.
• Extractables and leachables.
• Delivered-dose uniformity.
• Aerodynamic particle-size distribution.
• Spray pattern and plume geometry.
• In-use stability.
• Device robustness and human factors.
• Container-closure integrity.
• Comparative clinical endpoint requirements where equivalence cannot be established through in vitro testing alone.

For a generic combination inhalation product, a sponsor may need to coordinate ANDA requirements with complex drug-device combination-product expectations. A 505(b)(2) strategy may provide more flexibility for a reformulated or redesigned product but generally requires a stronger clinical and regulatory justification.

What commercial opportunities exist for excipient suppliers and manufacturers?

The addressable opportunity is concentrated in specialized inputs and integrated manufacturing rather than commodity excipients.

High-value opportunities include:

1. Pharmaceutical-grade benzalkonium chloride with controlled impurity and adsorption profiles.
2. High-purity edetate disodium for inhalation use.
3. Low-extractables cartridge polymers and elastomers.
4. Sterile filling and multidose cartridge assembly.
5. Nozzle and metering components.
6. Preservative-free cartridge systems.
7. In-use stability testing services.
8. Aerosol-performance analytical platforms.
9. Regional contract manufacturing for soft-mist inhalers.
10. Device and formulation licensing.

Manufacturers with validated soft-mist production lines have a structural advantage. The capital requirement, specialized analytical testing, and device qualification reduce the number of credible competitors compared with conventional oral solid-dose generics.

Key Takeaways

• STIOLTO RESPIMAT contains tiotropium bromide and olodaterol hydrochloride in an aqueous, propellant-free formulation.
• Its principal excipients are benzalkonium chloride, edetate disodium, hydrochloric acid, and water for injection.
• The product’s commercial protection depends heavily on the Respimat inhaler, cartridge, nozzle, metering system, and aerosol performance.
• Preservative-free reformulation is the clearest excipient-led differentiation opportunity.
• Cartridge materials, extractables control, sterile filling, and in-use stability create higher-value manufacturing opportunities.
• Generic entry risk depends on the Orange Book patent list, formulation and device claims, Paragraph IV litigation, settlements, and the ability to develop an approvable inhaler.
• A competitor can potentially use an ANDA, a skinny-label strategy, an authorized generic, or a 505(b)(2) pathway.
• Device licensing and regional manufacturing partnerships may be more commercially valuable than licensing the active ingredients.

FAQs

What is the preservative in STIOLTO RESPIMAT?

Benzalkonium chloride is the principal preservative identified in the U.S. prescribing information.

Does STIOLTO RESPIMAT contain lactose?

No. STIOLTO RESPIMAT is an aqueous soft-mist inhalation solution and does not use lactose as a dry-powder carrier.

Is STIOLTO RESPIMAT a propellant-based inhaler?

No. Respimat generates a soft mist from an aqueous solution through mechanical device operation and does not use a hydrofluoroalkane propellant.

Can a generic STIOLTO product use a different inhaler?

Potentially, but the sponsor must establish pharmaceutical and device performance equivalence and avoid enforceable device or formulation patent claims. A different inhaler may require an alternative regulatory pathway or additional data.

Which excipient has the greatest reformulation value?

Benzalkonium chloride has the greatest visible differentiation potential because a preservative-free version could address tolerability and patient-preference considerations. Removing it would require a new microbial-control and stability strategy.

References

1. Boehringer Ingelheim Pharmaceuticals, Inc. (2024). STIOLTO RESPIMAT: U.S. prescribing information. U.S. Food and Drug Administration.

2. U.S. Food and Drug Administration. (1998). Metered dose inhaler and dry powder inhaler drug products: Chemistry, manufacturing, and controls documentation. FDA.

3. U.S. Food and Drug Administration. (2018). Guidance for industry: Metered dose inhaler and dry powder inhaler drug products submitted in abbreviated new drug applications. FDA.

4. U.S. Food and Drug Administration. (2025a). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

5. U.S. Food and Drug Administration. (2025b). FDA’s policy and implementation of the Hatch-Waxman amendments. FDA.