List of Excipients in Branded Drug REQUIP

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Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Physicians Total Care Inc	REQUIP	ropinirole hydrochloride	54868-6093	CARBOXYMETHYLCELLULOSE SODIUM
Physicians Total Care Inc	REQUIP	ropinirole hydrochloride	54868-6093	GLYCERYL BEHENATE
Physicians Total Care Inc	REQUIP	ropinirole hydrochloride	54868-6093	HYDROGENATED CASTOR OIL
Physicians Total Care Inc	REQUIP	ropinirole hydrochloride	54868-6093	HYPROMELLOSES
Physicians Total Care Inc	REQUIP	ropinirole hydrochloride	54868-6093	LACTOSE MONOHYDRATE
Physicians Total Care Inc	REQUIP	ropinirole hydrochloride	54868-6093	MAGNESIUM STEARATE
Physicians Total Care Inc	REQUIP	ropinirole hydrochloride	54868-6093	MALTODEXTRIN

Requip (Ropinirole) Excipient Strategy and Commercial Opportunities

Last updated: November 8, 2026

Requip contains ropinirole, a small-molecule dopamine agonist approved for Parkinson’s disease and moderate-to-severe primary restless legs syndrome. The active ingredient is long off patent, and generic ropinirole products are widely approved in immediate-release and extended-release forms. Commercial opportunity therefore depends on manufacturing efficiency, excipient differentiation, dosage-form performance, and channel strategy rather than molecule-level exclusivity.

The strongest opportunities are:

• Lower-cost, high-throughput immediate-release tablets.
• Extended-release tablets with robust in-vitro and in-vivo performance.
• Dye-free, lactose-free, and low-pill-burden products.
• Dose-flexible products for titration and geriatric use.
• Contract manufacturing and private-label supply.
• Regional licensing of modified-release technology.

What is Requip and which formulations are commercially relevant?

Requip is the brand name for ropinirole hydrochloride. GlaxoSmithKline commercialized the product in immediate-release and extended-release forms. The immediate-release product was approved for Parkinson’s disease and restless legs syndrome. Requip XL was developed as a once-daily extended-release product for Parkinson’s disease.[1][2]

Product	Active ingredient	Release profile	Main use	Commercial status
Requip tablets	Ropinirole hydrochloride	Immediate release	Parkinson’s disease; restless legs syndrome	Generic competition
Requip XL tablets	Ropinirole hydrochloride	Extended release	Parkinson’s disease	Generic extended-release competition
Generic ropinirole tablets	Ropinirole hydrochloride	Immediate release	Same approved indications, subject to product labeling	Widely available
Generic ropinirole ER tablets	Ropinirole hydrochloride	Extended release	Parkinson’s disease	More technically demanding than IR

Ropinirole is administered across a broad dose range. Parkinson’s disease treatment requires gradual titration, while restless legs syndrome generally uses lower doses. This creates an excipient and packaging opportunity around dose precision, low-dose content uniformity, tablet identification, and patient-friendly titration packs.

When does Requip lose exclusivity?

Requip has lost practical market exclusivity. Ropinirole is a small molecule, so there is no biosimilar pathway and no biologic exclusivity barrier.

The original active-ingredient and product-protection period expired years ago. FDA-approved generic immediate-release ropinirole products are listed in the Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book.[3] Generic extended-release products have also entered the market, although the technical and regulatory requirements for modified-release bioequivalence are more demanding.

Exclusivity category	Requip status
New chemical entity exclusivity	Expired
Pediatric exclusivity	No current commercial relevance
Orphan exclusivity	Not applicable
Biologic exclusivity	Not applicable
Active brand market exclusivity	Expired
Generic ANDA pathway	Available
Patent-driven commercial barrier	Limited to any surviving product-specific claims, if applicable

Patent expiry is no longer the principal barrier to entry. The commercial barrier is product execution: reliable dissolution, acceptable bioequivalence, low manufacturing cost, and sufficient distribution.

What patents protect ropinirole and Requip formulations?

The historic patent estate covered ropinirole as a chemical entity, pharmaceutical compositions, and therapeutic use. Those rights are no longer a meaningful barrier to standard generic entry in the United States.

Current commercial analysis should distinguish between:

1. Expired composition-of-matter rights.
2. Expired or nonblocking method-of-use claims.
3. Historic extended-release formulation rights.
4. Any later patents directed to manufacturing processes, specific excipient ratios, coatings, or alternative release systems.
5. Patents owned by third parties covering platform technology rather than ropinirole itself.

The practical patent position is summarized below.

Patent category	Risk to a conventional IR generic	Risk to an ER generic
Ropinirole composition of matter	Low	Low
Standard tablet excipients	Low	Low
Immediate-release manufacturing process	Low	Low
Extended-release matrix design	Minimal for noninfringing designs, but formulation-specific review required	Moderate
Coating and multiparticulate technology	Low for conventional tablets	Moderate
Method-of-use claims	Low for labeled generic indications after expiry	Low to moderate
Manufacturing know-how	Commercially relevant even without patent protection	High relative to IR

The key point is that excipient selection can create a differentiated product without creating meaningful exclusivity. Most common excipients are not patent-protected in a way that would support a durable ropinirole franchise. Value is more likely to come from formulation know-how, process controls, regulatory documentation, and customer access.

What excipients are used in Requip immediate-release tablets?

The Requip immediate-release label identifies conventional oral-tablet excipients, including lactose, microcrystalline cellulose, croscarmellose sodium, and magnesium stearate.[1] These excipients support standard wet or dry granulation, direct compression, disintegration, lubrication, and tablet robustness.

Immediate-release excipient functions

Excipient class	Typical role in ropinirole IR tablets	Commercial consideration
Lactose	Diluent and compressibility aid	Low cost; may exclude lactose-intolerant or avoidance-focused segments
Microcrystalline cellulose	Filler and dry binder	Supports direct compression and tablet strength
Croscarmellose sodium	Superdisintegrant	Important for rapid tablet breakup
Magnesium stearate	Lubricant	Excess levels can slow dissolution
Film coating	Identification, swallowability, moisture and handling protection	Supports strength differentiation and product appearance
Colorants	Strength identification	Dye-free products may support niche positioning

Ropinirole tablets contain small quantities of active ingredient at the lower strengths. Uniform distribution is therefore a central manufacturing issue. Blend segregation, low-dose assay variation, and lubricant overmixing can create dissolution or content-uniformity failures.

IR excipient strategy

The lowest-risk generic platform is a conventional lactose or microcrystalline-cellulose tablet using croscarmellose sodium as the primary disintegrant. A formulation developer can improve commercial positioning through:

• Lactose-free substitution with mannitol, dibasic calcium phosphate, or additional microcrystalline cellulose.
• Dye-free film coating.
• Reduced tablet weight for easier swallowing.
• Improved tablet hardness without slowing disintegration.
• Lower magnesium stearate exposure to protect dissolution.
• Robust low-dose blending and sampling controls.
• Scored or identifiable tablets where permitted by the approved design.

Mannitol can improve mouthfeel and support a more premium excipient profile, but it can increase cost and may require tighter moisture and compression controls. Dibasic calcium phosphate can improve flow and hardness but may create compatibility, density, or disintegration tradeoffs. Co-processed excipients can improve direct compression but must be justified through comparative dissolution and stability data.

What excipients are used in Requip XL extended-release tablets?

Requip XL uses a controlled-release tablet design. The product label identifies excipients including hypromellose, hydrogenated castor oil, carnauba wax, colloidal silicon dioxide, lactose, and magnesium stearate, with coating components varying by strength.[2]

Extended-release excipient functions

Excipient class	Function in ER formulation
Hypromellose	Hydrophilic matrix former controlling water penetration and drug diffusion
Hydrogenated castor oil	Hydrophobic release modifier and matrix component
Carnauba wax	Hydrophobic barrier and release-control aid
Lactose	Soluble diluent that can create porosity as it dissolves
Colloidal silicon dioxide	Flow aid and process-support excipient
Magnesium stearate	Lubricant
Film coating	Product protection, identification, and handling performance

The principal formulation challenge is release consistency across pH, agitation, fed and fasted conditions, and tablet-strength changes. An ER generic must reproduce the relevant pharmacokinetic profile without necessarily duplicating every qualitative and quantitative excipient detail. The formulation must meet applicable FDA requirements for pharmaceutical equivalence and bioequivalence.[3][4]

ER excipient strategy

A developer can pursue several technically distinct approaches:

1. Hydrophilic matrix tablets. Hypromellose remains the most established option. Polymer viscosity grade, particle size, hydration rate, compression force, and tablet geometry affect release.

2. Hydrophilic-hydrophobic hybrid matrices. Combining hypromellose with waxes or lipophilic release modifiers can reduce rapid initial release and improve robustness.

3. Coated matrix tablets. A functional film can reduce dose dumping risk and narrow dissolution variability, but coating uniformity becomes a critical process parameter.

4. Multiparticulate systems. Drug-layered pellets or coated granules can improve release control and reduce sensitivity to tablet geometry. They also increase manufacturing complexity and may create a stronger differentiated product.

5. Lipid or wax-based systems. These can provide cost-effective release control but require careful evaluation of food effects, mechanical strength, and scale-up behavior.

6. Lower-excipient-load formulations. A smaller tablet can improve patient acceptance, but lower mass may make content uniformity and release control more difficult.

A conventional hypromellose matrix is generally the lowest-risk route. Multiparticulates and coated systems offer stronger differentiation but require higher capital investment and more extensive development work.

What FDA regulatory pathway applies to generic Requip?

Immediate-release ropinirole tablets can generally be developed through an ANDA referencing the relevant FDA-listed reference product. The applicant must demonstrate pharmaceutical equivalence and bioequivalence, comply with current good manufacturing practice, and satisfy labeling and quality requirements.[3][5]

Extended-release ropinirole products require more complex development. FDA review typically focuses on:

• Comparative dissolution across multiple media and time points.
• Dose proportionality or strength-scaling justification.
• Fed and fasted pharmacokinetic behavior.
• Alcohol interaction and dose-dumping risk.
• Stability under commercial packaging conditions.
• Tablet mechanical integrity.
• Manufacturing-process reproducibility.
• Comparative release performance across strengths.

FDA’s modified-release guidance places substantial emphasis on discriminatory dissolution methods and in-vivo performance.[4] A formulation that matches a single dissolution profile but fails under altered agitation, pH, or food conditions has limited regulatory value.

How strong is the patent estate for Requip?

The patent estate is weak as a current barrier to conventional generic entry. The molecule is mature, and the principal opportunity is freedom to operate around formulation and process design.

Estate factor	Assessment
Composition-of-matter protection	Expired
Basic IR tablet protection	Low
ER platform protection	Product-specific review required
Trade-secret manufacturing know-how	Relevant
Excipient supply exclusivity	Generally low
Regulatory exclusivity	Expired
Litigation exposure	Low for standard IR products; higher for differentiated ER designs

A company using the same functional excipient classes as Requip XL does not automatically infringe a patent. Infringement depends on claim language, quantitative limitations, process steps, and jurisdiction. Conversely, a technically different formulation may still encounter claims directed to release profiles, coating structures, or manufacturing steps.

Are there Paragraph IV challenges to Requip?

Paragraph IV litigation is no longer the central market issue for standard ropinirole products. Paragraph IV certification is relevant when an ANDA applicant addresses a listed patent that remains active. Because the core Requip exclusivity period has expired, entry risk is more likely to involve routine ANDA review, patent-clearance analysis, and formulation-specific freedom-to-operate work than a high-value branded-product challenge.

For an extended-release product, the relevant question is not whether the ropinirole molecule is patent-free. It is whether the proposed matrix, coating, release-control mechanism, or manufacturing process falls within any unexpired third-party claims.

What generic entry risks exist for ropinirole?

Immediate-release risk

IR ropinirole is a low-barrier generic opportunity. Risks include:

• Low selling prices.
• High competition from established generic manufacturers.
• Limited prescriber differentiation.
• Small revenue per tablet.
• Customer concentration among wholesalers and pharmacy benefit managers.
• Margin pressure from multiple approved suppliers.

The principal advantage is manufacturing simplicity. A qualified tablet plant can produce the product using common excipients and standard equipment.

Extended-release risk

ER ropinirole offers better differentiation but greater technical risk:

• In-vitro/in-vivo correlation may be weak.
• Food effects may alter exposure.
• Release profiles may shift during scale-up.
• Polymer lots can vary in viscosity and hydration behavior.
• Coating defects can cause dose dumping.
• Bioequivalence studies are more expensive.
• Market demand is smaller than for common IR products.

The commercial case is strongest for manufacturers that already operate modified-release infrastructure.

What commercial opportunities exist for excipient suppliers?

Excipient suppliers can target ropinirole through formulation platforms rather than molecule-specific sales.

Immediate-release opportunities

• Direct-compression blends for low-dose tablets.
• Co-processed excipients that improve content uniformity.
• Lactose-free filler-binder systems.
• Dye-free coating systems.
• Low-moisture formulations for stability-sensitive plants.
• Lubricant systems that preserve rapid dissolution.
• Ready-to-use premixes that reduce scale-up time.

Extended-release opportunities

• Hypromellose grades optimized for low-dose drugs.
• Polymer combinations that reduce burst release.
• Functional coatings with controlled permeability.
• Wax-polymer systems for robust release across agitation conditions.
• Multiparticulate coating platforms.
• Excipient packages designed to reduce food-effect sensitivity.
• Process analytical technology for matrix-density and coating-thickness control.

The best commercial pitch is a documented platform with data on dissolution robustness, scale-up, stability, and bioequivalence support. A generic excipient catalog without formulation data has limited value in a mature molecule.

How does ropinirole compare with other Parkinson’s disease drugs?

Ropinirole competes with pramipexole, rotigotine, levodopa combinations, and other dopamine agonists. Its formulation opportunity differs from these products.

Drug	Main dosage forms	Excipient opportunity	Competitive constraint
Ropinirole	IR and ER tablets	Low-cost tablets; modified-release matrices	Mature generic market
Pramipexole	IR and ER tablets	Low-dose uniformity; ER matrix	Strong generic competition
Rotigotine	Transdermal patch	Adhesive, permeation, patch stability	Device and transdermal complexity
Levodopa/carbidopa	IR, ER, orally disintegrating and other forms	Rapid disintegration; stability; combination uniformity	Large, crowded market
Apomorphine	Injectable and other specialized forms	Sterility and delivery system	Higher regulatory and device barriers

Ropinirole’s strongest advantage is oral solid-dose manufacturability. Its weakness is limited pricing power.

What licensing deals are relevant to ropinirole?

No molecule-level licensing opportunity is required to commercialize a conventional generic ropinirole product. Licensing value is more likely to arise from:

• Extended-release platform technology.
• Multiparticulate coating systems.
• Co-processed excipient technology.
• Regional commercialization rights.
• Contract manufacturing arrangements.
• Private-label supply agreements.
• Authorized-generic or branded-generic distribution.

A technology owner can license a ropinirole ER formulation where the license includes development data, manufacturing transfer, regulatory support, and freedom-to-operate analysis. The economic case is weaker for IR ropinirole because the formulation is easy to replicate and price competition is intense.

What is the revenue exposure for a ropinirole product?

Ropinirole revenue is generally exposed to generic price erosion. Revenue depends on dosage form and channel:

• IR tablets provide volume but limited unit economics.
• ER tablets provide greater technical differentiation and potentially better pricing.
• Institutional and mail-order channels may reward supply reliability.
• Retail pharmacy channels emphasize acquisition cost.
• Specialty or branded-generic positioning has limited durability without a meaningful patient benefit.

A manufacturer should model revenue by strength, not only by total prescriptions. Parkinson’s disease titration produces demand across multiple strengths, while restless legs syndrome tends to concentrate in lower-dose products. A supplier that can reliably support the full strength range may obtain a larger account share than one that offers only the highest-volume strength.

What manufacturing and IP barriers affect commercial entry?

The manufacturing barriers are modest for IR tablets and material for ER tablets.

Immediate-release manufacturing controls

• Low-dose blend uniformity.
• Segregation control during transfer.
• Granule or powder flow.
• Lubrication time.
• Tablet hardness and friability.
• Rapid disintegration.
• Coating weight gain and color uniformity.

Extended-release manufacturing controls

• Polymer viscosity and particle-size consistency.
• Matrix density and compression force.
• Coating thickness.
• Water activity and residual moisture.
• Dissolution profile across pH and agitation conditions.
• Alcohol compatibility.
• Food-effect performance.
• Scale-up reproducibility.

Geographic manufacturing strategy should prioritize regions with established FDA, European Medicines Agency, and other major-market ANDA or generic approval capabilities. Local production may improve tender access, but the product remains vulnerable to price competition unless the manufacturer has a cost or supply-reliability advantage.

Key Takeaways

• Requip is ropinirole, a mature small-molecule product with expired core exclusivity.
• Immediate-release ropinirole is a low-complexity, low-margin generic opportunity.
• Extended-release ropinirole offers greater differentiation but requires stronger formulation and bioequivalence capabilities.
• Core excipients include lactose, microcrystalline cellulose, croscarmellose sodium, magnesium stearate, hypromellose, hydrogenated castor oil, and carnauba wax.
• Excipient differentiation is commercially useful when it improves dissolution robustness, swallowing, lactose avoidance, or manufacturing efficiency.
• The strongest supplier opportunity is a formulation platform supported by development and scale-up data.
• Biosimilar risk is not relevant because ropinirole is a small molecule.
• Current litigation and Paragraph IV risk are secondary to formulation-specific freedom-to-operate analysis.
• Revenue exposure is highest in low-price generic channels, while ER and private-label products offer better differentiation.
• The main barrier for ER products is process and bioequivalence execution, not molecule-level patent protection.

FAQs

Is ropinirole still protected by patents?

The core ropinirole exclusivity period has expired. Product-specific formulation or process claims must be reviewed separately, especially for extended-release products.

Can a company launch a lactose-free ropinirole tablet?

Yes. A lactose-free formulation can be developed using alternative fillers such as mannitol, microcrystalline cellulose, or dibasic calcium phosphate, subject to pharmaceutical equivalence, bioequivalence, stability, and manufacturing requirements.

Which excipient is most important in ropinirole extended-release tablets?

Hypromellose is usually the central release-controlling excipient in a hydrophilic matrix. Its viscosity grade, concentration, hydration behavior, and interaction with other excipients materially affect dissolution.

Does ropinirole have biosimilar competition?

No. Ropinirole is a chemically synthesized small molecule and is approved through generic drug pathways rather than biosimilar pathways.

Is Requip XL more commercially attractive than immediate-release ropinirole?

Requip XL-type products offer more technical differentiation and potentially better margins, but they require more expensive development, stronger manufacturing controls, and more complex bioequivalence work than immediate-release tablets.

References

1. GlaxoSmithKline. (2012). Requip tablets (ropinirole hydrochloride) prescribing information. U.S. Food and Drug Administration.

2. GlaxoSmithKline. (2012). Requip XL (ropinirole hydrochloride extended-release tablets) prescribing information. U.S. Food and Drug Administration.

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

4. U.S. Food and Drug Administration. (2003). Guidance for industry: Extended release oral dosage forms: Development, evaluation, and application of in vitro/in vivo correlations. FDA.

5. U.S. Food and Drug Administration. (2024). ANDA submissions: Content and format. FDA.