List of Excipients in Branded Drug RASAGILINE MESYLATE

Generic Drugs Containing RASAGILINE MESYLATE

Company	Ingredient	NDC	Excipient
Mylan Pharmaceuticals Inc	rasagiline mesylate	0378-1270	CITRIC ACID MONOHYDRATE
Mylan Pharmaceuticals Inc	rasagiline mesylate	0378-1270	CROSCARMELLOSE SODIUM
Mylan Pharmaceuticals Inc	rasagiline mesylate	0378-1270	MICROCRYSTALLINE CELLULOSE 102
Mylan Pharmaceuticals Inc	rasagiline mesylate	0378-1270	SILICON DIOXIDE

What are the Most Frequently-Used Excipients in RASAGILINE MESYLATE?

# Of NDCs	Excipient
2	CELLULOSE, MICROCRYSTALLINE
3	CITRIC ACID MONOHYDRATE
1	CROSCARMELLOSE SODIUM
1	MICROCRYSTALLINE CELLULOSE 102

Rasagiline Mesylate Excipient Strategy and Commercial Opportunities

Last updated: September 8, 2026

Rasagiline mesylate is an oral monoamine oxidase-B inhibitor marketed in the United States as Azilect and available through generic tablets. The reference product uses a conventional immediate-release tablet platform with mannitol, corn starch, pregelatinized starch, colloidal silicon dioxide, stearic acid and talc. Commercial opportunities center on lower-cost direct compression, improved low-dose content uniformity, orally disintegrating tablets, differentiated geriatric products and combination therapies rather than on basic generic substitution alone. FDA regulatory risk is moderate for conventional tablets and higher for modified delivery systems or products that claim superior clinical performance. [1]

What is rasagiline mesylate and how is it dosed?

Rasagiline is a selective monoamine oxidase-B inhibitor used for Parkinson's disease. It is administered once daily at a usual dose of 1 mg, either as monotherapy or as an adjunct to levodopa. A 0.5 mg dose is used in some patients receiving concomitant ciprofloxacin or other CYP1A2 inhibitors. [1]

Active pharmaceutical ingredient and salt conversion

Rasagiline is commonly supplied as rasagiline mesylate. The salt improves handling and manufacturing characteristics compared with the free base.

Parameter	Approximate value
Active moiety	Rasagiline
Common salt	Rasagiline mesylate
Reference strengths	0.5 mg and 1 mg rasagiline
Equivalent rasagiline mesylate at 1 mg strength	Approximately 1.46 mg
Dosage form	Immediate-release tablet
Administration	Once daily
Therapeutic class	Monoamine oxidase-B inhibitor
Primary indication	Parkinson's disease

Product labeling generally expresses strength as rasagiline, not the total mass of rasagiline mesylate. This distinction affects API dispensing, assay calculations, overage strategy and finished-product specifications.

What excipients are used in the Azilect reference tablet?

The Azilect immediate-release tablet uses a low-complexity excipient system:

Excipient	Functional role
Mannitol	Diluent, mouthfeel modifier and possible compression aid
Corn starch	Diluent and disintegrant
Pregelatinized starch	Binder and disintegrant
Colloidal silicon dioxide	Glidant and moisture-control aid
Stearic acid	Lubricant
Talc	Anti-adherent and flow aid

The formulation is commercially important because it does not depend on a specialized delivery technology. A generic manufacturer can generally pursue a conventional immediate-release tablet using widely available compendial excipients, provided the finished product meets quality, dissolution, bioequivalence and stability requirements. [1,2]

Why the reference excipient system matters

The reference composition establishes a practical benchmark for:

• tablet hardness and friability;
• disintegration time;
• dissolution across relevant pH conditions;
• assay and content uniformity at the 0.5 mg strength;
• moisture sensitivity;
• powder flow;
• tablet weight and dimensions;
• impurity formation during storage.

Exact quantitative amounts are not necessarily disclosed in public labeling. A generic applicant therefore needs to reproduce critical product performance rather than duplicate the qualitative and quantitative formula in every case.

Which excipient strategy is best for generic rasagiline tablets?

The lowest-risk strategy is a conventional immediate-release formulation using a small number of established excipients and a manufacturing process that controls low-dose blend uniformity.

Direct compression

Direct compression can reduce processing steps and manufacturing cost. A formulation may use mannitol or microcrystalline cellulose as the principal diluent, with a superdisintegrant such as crospovidone or sodium starch glycolate, colloidal silicon dioxide as a glidant and magnesium stearate or stearic acid as lubricant.

The main technical risk is segregation. Rasagiline is present at a very low concentration relative to the tablet mass. Differences in particle size, density and electrostatic behavior between API and excipients can produce content-uniformity failures.

Critical controls include:

• API particle-size distribution;
• premixing or ordered blending;
• blend sampling design;
• lubricant addition time;
• hopper residence time;
• compression-speed changes;
• segregation during transfer;
• tablet weight control;
• assay by individual dosage unit.

Wet granulation

Wet granulation can improve blend uniformity and flow, but it adds process complexity. It may be useful where the API has poor flow, poor compressibility or segregation behavior.

Potential disadvantages include:

• greater capital and operating cost;
• residual-moisture control;
• possible hydrolysis or degradation;
• longer development timelines;
• more complex scale-up;
• greater process-validation burden.

For a low-dose product with acceptable API flow, wet granulation is unlikely to produce a sufficient commercial advantage unless it materially improves content uniformity or dissolution.

Roller compaction

Roller compaction offers a dry-granulation alternative where flow and segregation are problematic but water exposure is undesirable. It can reduce moisture risk compared with wet granulation, although ribbon density and granule size must be controlled carefully.

Lubrication strategy

Over-lubrication can slow dissolution and reduce tablet strength. Magnesium stearate is common in generic tablet development but may require tighter control than stearic acid depending on the target dissolution profile. The formulation should establish a defined lubrication endpoint rather than relying only on fixed blending time.

What formulation patents could protect rasagiline mesylate products?

Formulation patents may protect a specific dosage form, excipient combination, particle-size distribution, manufacturing process, stability profile or release characteristic. They are separate from patents covering rasagiline itself or its method of use.

Potential formulation-IP categories

IP category	Potential claim focus	Commercial value
Immediate-release tablet	Defined excipient ranges, hardness or dissolution profile	Moderate
Orally disintegrating tablet	Disintegration time, taste masking and dose uniformity	High if clinically differentiated
Multiparticulate product	Granules, pellets or capsule filling	Moderate
Fixed-dose combination	Rasagiline with another Parkinson's therapy	High if clinically useful
Stability formulation	Reduced degradation or improved impurity control	Moderate
Manufacturing process	Granulation, blending or compression conditions	Moderate
Particle engineering	API size, morphology or agglomeration control	Moderate
Modified release	Controlled exposure or reduced dosing frequency	Potentially high, but technically difficult

A formulation patent is more defensible when it links composition to a measurable technical result, such as improved content uniformity, faster disintegration, reduced impurity growth or a clinically relevant pharmacokinetic profile. Broad claims covering ordinary excipients in routine amounts are more vulnerable to obviousness challenges.

What commercial opportunities exist for new rasagiline excipient systems?

The largest opportunities are in patient convenience, manufacturing efficiency and combination products.

Orally disintegrating tablets

Parkinson's disease is prevalent in an older population with dysphagia, impaired dexterity and difficulty handling conventional tablets. An orally disintegrating tablet could improve administration for selected patients.

A viable ODT strategy would require:

• rapid disintegration without excessive friability;
• acceptable taste or low exposure in the mouth;
• accurate delivery of a low API dose;
• packaging protection against humidity;
• stable dissolution after storage;
• compatibility with geriatric handling requirements.

Mannitol is attractive for ODTs because it provides a cooling mouthfeel and can support a pleasant sensory profile. Crospovidone, low-substituted hydroxypropyl cellulose and directly compressible excipients may support rapid disintegration. Taste masking is important because rasagiline-containing granules or particles may produce an unacceptable bitter or medicinal taste.

Orally disintegrating mini-tablets

Mini-tablets could provide a more flexible platform for 0.5 mg and 1 mg dosing. They may also support dose titration or combination packaging. The development challenge is maintaining uniformity across very small units while preventing handling loss and segregation.

Fixed-dose combinations

Rasagiline is used with levodopa and may be used in broader Parkinson's treatment regimens. A fixed-dose combination with levodopa/carbidopa or another established Parkinson's therapy could reduce pill burden, but it would face substantial formulation and regulatory complexity.

Risks include:

• different dose ratios;
• different stability profiles;
• separate dissolution requirements;
• interaction between APIs and excipients;
• food-effect assessment;
• dose flexibility limitations;
• clinical justification for the combination.

A combination product is more commercially defensible than a simple excipient substitution if it provides a clear adherence or dosing benefit.

Packaging and adherence products

Rasagiline tablets are small, low-dose products that can be supplied in bottles, unit-dose blisters or calendar packaging. Calendar blistering and adherence-oriented packaging may support differentiation without changing the dosage form. Packaging claims generally do not create the same regulatory burden as a new drug-delivery system, but moisture protection and child-resistant requirements must be addressed.

How does rasagiline mesylate compare with competing Parkinson's drugs?

Rasagiline competes with selegiline, safinamide, dopamine agonists, levodopa combinations and other adjunctive treatments. Its principal commercial advantages are once-daily dosing and a simple tablet platform.

Product or class	Main formulation opportunity	Commercial consideration
Rasagiline	Generic immediate-release tablet, ODT, combination product	Low manufacturing complexity; price competition
Selegiline	ODT and capsule products	Established alternative MAO-B inhibitor
Safinamide	Conventional tablet	Different pharmacology and branded positioning
Levodopa/carbidopa	Extended-release, intestinal or inhaled delivery	Larger market but much more complex competition
Dopamine agonists	Extended-release tablets and transdermal systems	Strong convenience differentiation
Amantadine	Extended-release products	Opportunity for symptom-specific positioning

Rasagiline's once-daily schedule limits the value of a conventional extended-release product. A new delivery system would need to show a meaningful benefit, such as reduced peak-related tolerability issues, improved adherence or a clinically useful combination.

What is the FDA regulatory status of rasagiline mesylate?

The FDA approved Azilect as an oral tablet for Parkinson's disease. Generic rasagiline tablets can generally be pursued through the abbreviated new drug application pathway under section 505(j) of the Federal Food, Drug, and Cosmetic Act. The applicant must demonstrate pharmaceutical equivalence and bioequivalence to the relevant reference listed drug. [1,3]

FDA requirements for a conventional generic

A typical 505(j) program will address:

• active ingredient identity and salt form;
• strength and dosage form;
• inactive ingredients;
• comparative dissolution;
• pharmacokinetic bioequivalence;
• assay and content uniformity;
• impurities and degradation products;
• stability;
• container-closure system;
• manufacturing controls;
• labeling requirements;
• patent certification under the Hatch-Waxman framework.

The most commercially efficient path is usually a tablet that remains close to the reference product in dosage form, release profile and administration instructions.

What is the Orange Book status of rasagiline?

The FDA Orange Book identifies reference listed drugs, approved abbreviated applications and patent or exclusivity information relevant to approved products. Rasagiline's historical protection included patents covering the active compound and methods of treatment. Those core protections have expired or are no longer the principal barrier to ordinary generic entry in the United States. Current commercial diligence must distinguish expired historical patents from any still-listed patent, pediatric exclusivity, litigation stay or product-specific listing. [3]

Patent and exclusivity considerations

Protection type	Relevance to rasagiline
Core compound patent	Historical barrier; no longer the main generic barrier
Method-of-use patent	May affect labeling and skinny-label strategy if listed and enforceable
Formulation patent	Could affect a specific dosage form or product design
Pediatric exclusivity	Must be checked against the applicable FDA listing
New chemical entity exclusivity	Historical period associated with original approval
ANDA exclusivity	Depends on the first qualifying generic challenge
Patent certification	Paragraph I, II, III or IV certification may be required

A company developing a standard generic tablet should not assume that the absence of a core compound patent eliminates all risk. The relevant assessment is the current Orange Book entry, approved labeling and any pending or settled litigation.

Are there Paragraph IV challenges and generic entry risks?

Generic entry risk is structurally high because rasagiline is an established small-molecule tablet with a once-daily regimen and no biologic manufacturing barrier. The principal entry risks are commercial rather than scientific.

Paragraph IV issues

A Paragraph IV certification states that a listed patent is invalid, unenforceable or will not be infringed by the proposed generic. If the relevant patent holder sues within the statutory period, FDA approval may be subject to a 30-month stay, subject to statutory exceptions and court developments. [4]

For rasagiline, the main diligence questions are:

1. Which patents are currently listed for the relevant reference product?
2. Are any listed claims directed to the proposed tablet rather than the active ingredient?
3. Does the generic label omit protected method-of-use information?
4. Are there settlement agreements restricting launch timing?
5. Is first-filer exclusivity relevant to the proposed ANDA?
6. Do formulation or manufacturing claims create infringement exposure?

Because patent landscapes and Orange Book listings change, legal conclusions must be tied to the filing date of the proposed ANDA and the current FDA record.

How strong is the rasagiline patent estate?

The historical compound estate was commercially important, but the current estate for conventional rasagiline tablets is materially weaker than the estate for a recently launched branded medicine. A generic tablet using conventional excipients is unlikely to face a biologic-style barrier or a complex manufacturing patent thicket.

Strength assessment

Factor	Assessment
Core molecule protection	Low current blocking risk
Conventional tablet formulation	Low to moderate
ODT formulation	Moderate, depending on claims
Fixed-dose combination	Moderate to high
Manufacturing process	Moderate if process-specific claims are valid
Clinical differentiation	Limited for ordinary tablets
Supply-chain barrier	Low to moderate
Regulatory complexity	Low for standard tablets; higher for new dosage forms

The strongest defensible IP opportunity is likely to arise from a clinically meaningful product change rather than from minor substitution of mannitol, starch or lubricant grades.

What manufacturing and IP barriers affect commercial entry?

Manufacturing barriers are manageable but concentrated in low-dose handling.

Key technical barriers

• maintaining uniform distribution of less than 2 mg of salt per tablet;
• preventing segregation during scale-up;
• controlling blend and tablet assay variability;
• achieving rapid and reproducible disintegration;
• controlling moisture and impurity growth;
• maintaining dissolution after long-term storage;
• sourcing qualified API at competitive cost;
• avoiding over-lubrication;
• validating cleaning for a potent low-dose compound.

Geographic coverage

A formulation strategy may require separate assessments for the United States, European Union, Japan, Canada, Australia and emerging markets. Excipients accepted in one jurisdiction may require different documentation or may be subject to local compendial expectations. Patent status also varies by country, particularly for formulation and method-of-use claims.

For Europe, a generic or hybrid application may rely on the applicable national, decentralized or centralized pathway depending on the product and legal basis. In the United States, the key route for a conventional copy is the ANDA pathway. Regulatory exclusivity and patent timing should be modeled separately by jurisdiction.

What revenue exposure and market opportunities exist?

Rasagiline revenue is exposed to generic price erosion because the product is an established small molecule with multiple potential manufacturers. Branded revenue is most vulnerable in markets where generic substitution is automatic and reimbursement favors the lowest-cost supplier.

Commercial opportunity remains in:

• reliable low-cost supply;
• dual-strength portfolios;
• ODT products;
• dysphagia-focused products;
• calendar blister packaging;
• regional licensing;
• contract manufacturing;
• fixed-dose combinations;
• emerging-market distribution;
• lifecycle products with differentiated labeling or convenience.

A standard generic tablet is likely to compete primarily on cost, supply reliability, regulatory execution and market access. An ODT or combination product can command stronger differentiation but requires greater development investment and may need additional clinical or bioequivalence work.

What licensing deals are relevant to rasagiline?

Rasagiline was developed and commercialized through a collaboration involving Teva and the drug's original development partners. The product was marketed by Teva as Azilect. [5]

Current licensing opportunities are more likely to involve:

• regional commercialization rights;
• generic supply agreements;
• private-label manufacturing;
• ODT or combination-product development;
• API supply and technology transfer;
• co-development in markets with limited generic penetration.

A licensing agreement should allocate responsibility for patent certifications, product liability, pharmacovigilance, regulatory maintenance, supply interruption and launch timing. For a mature product, territorial market access and manufacturing economics may have greater value than broad global rights.

What litigation and settlement issues should companies monitor?

Rasagiline diligence should review:

• historic litigation involving the compound or treatment methods;
• current Orange Book patent listings;
• ANDA Paragraph IV complaints;
• 30-month stays;
• launch-at-risk decisions;
• generic settlement terms;
• authorized-generic arrangements;
• competition-law considerations;
• patent expiration and terminal-disclaimer dates.

Settlement agreements can affect the date on which a generic may launch, the scope of an authorized generic arrangement and the commercial value of first-filer status. A settlement date should not be treated as a substitute for reviewing the actual agreement and FDA patent records.

Key Takeaways

• Rasagiline mesylate is well suited to a conventional immediate-release generic tablet.
• The reference product uses mannitol, corn starch, pregelatinized starch, colloidal silicon dioxide, stearic acid and talc.
• The main technical risk is low-dose content uniformity, not complex drug delivery.
• Direct compression offers the lowest-cost development path when API flow and segregation are controlled.
• ODTs, mini-tablets, adherence packaging and fixed-dose combinations offer more meaningful commercial differentiation.
• Current generic risk is high because core molecule protection is historical and conventional tablet manufacturing is accessible.
• Formulation patents are most valuable when tied to measurable technical or clinical advantages.
• FDA Orange Book, patent certifications, litigation records and settlement agreements should be reviewed for the specific launch date and jurisdiction.
• The strongest commercial strategy is usually a dual approach: low-cost standard tablets for volume and a differentiated geriatric or combination product for margin.

FAQs

Can rasagiline mesylate be formulated with lactose?

Yes, lactose may be technically feasible, but compatibility, impurity formation, moisture sensitivity and patient labeling must be evaluated. The reference product does not rely on lactose, so a lactose-free formulation may offer a simpler differentiation message.

Is rasagiline mesylate suitable for a capsule product?

A capsule can deliver rasagiline mesylate, but a capsule is unlikely to provide a strong commercial advantage over a small immediate-release tablet unless it supports multiparticulates, flexible dosing or a combination product.

Would an extended-release rasagiline product have commercial value?

Potentially, but the once-daily reference regimen reduces the adherence benefit. A successful extended-release product would need evidence of improved tolerability, exposure control or clinical utility.

Can an ODT rasagiline product receive approval without a full clinical program?

A product that remains pharmaceutically equivalent and bioequivalent may follow an abbreviated pathway, but the regulatory requirements depend on its formulation, labeling, dosage form and reference-product relationship. Taste, disintegration, stability and bioequivalence remain central development issues.

What is the most attractive excipient opportunity for rasagiline?

The most practical opportunity is a low-dose, directly compressible, moisture-controlled tablet optimized for content uniformity and robust dissolution. The highest differentiation potential is in an ODT using a palatable mannitol-based platform with validated low-dose uniformity.

References

1. U.S. Food and Drug Administration. (2023). Azilect (rasagiline mesylate) tablets: Prescribing information. FDA.

2. U.S. Food and Drug Administration. (n.d.). DailyMed: Azilect, rasagiline mesylate tablet. National Library of Medicine.

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

4. U.S. Food and Drug Administration. (2017). Guidance for industry: 180-day exclusivity when multiple ANDAs are submitted on the same day. FDA.

5. Teva Pharmaceutical Industries Ltd. (2006). Azilect approval and commercialization materials. Teva.