List of Excipients in Branded Drug TIZANIDINE

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Actavis Pharma Inc	TIZANIDINE HYDROCHLORIDE	tizanidine hydrochloride	0591-2788	FD&C BLUE NO. 1
Actavis Pharma Inc	TIZANIDINE HYDROCHLORIDE	tizanidine hydrochloride	0591-2788	GELATIN
Actavis Pharma Inc	TIZANIDINE HYDROCHLORIDE	tizanidine hydrochloride	0591-2788	HYPROMELLOSES
Actavis Pharma Inc	TIZANIDINE HYDROCHLORIDE	tizanidine hydrochloride	0591-2788	SILICON DIOXIDE
Actavis Pharma Inc	TIZANIDINE HYDROCHLORIDE	tizanidine hydrochloride	0591-2788	SUCROSE
Actavis Pharma Inc	TIZANIDINE HYDROCHLORIDE	tizanidine hydrochloride	0591-2788	TITANIUM DIOXIDE

Generic Drugs Containing TIZANIDINE

Company	Ingredient	NDC	Excipient
Mylan Pharmaceuticals Inc	tizanidine	0378-0722	ANHYDROUS LACTOSE
Mylan Pharmaceuticals Inc	tizanidine	0378-0722	CELLULOSE, MICROCRYSTALLINE
Mylan Pharmaceuticals Inc	tizanidine	0378-0722	CROSCARMELLOSE SODIUM
Mylan Pharmaceuticals Inc	tizanidine	0378-0722	SILICON DIOXIDE
Mylan Pharmaceuticals Inc	tizanidine	0378-0722	STEARIC ACID
NCS HealthCare of KY Inc dba Vangard Labs	tizanidine	0615-6564	ANHYDROUS LACTOSE

What are the Most Frequently-Used Excipients in TIZANIDINE?

# Of NDCs	Excipient
1	ALCOHOL
2	AMMONIA
156	ANHYDROUS LACTOSE
1	BUTYL ALCOHOL
155	CELLULOSE, MICROCRYSTALLINE
3	COLLOIDAL SILICON DIOXIDE

Tizanidine Excipient Strategy and Commercial Opportunities

Last updated: August 27, 2026

Tizanidine is a low-cost, genericized oral muscle relaxant with limited active-ingredient exclusivity and substantial formulation opportunity. The strongest commercial opportunities are differentiated oral liquids, orally disintegrating or mini-tablet products, low-excipient-risk tablets, and formulations that control food effects and improve dose flexibility. A new formulation would likely require a 505(b)(2) strategy or an ANDA with demonstrated bioequivalence, depending on the dosage form and labeling claims.

What is the FDA status of tizanidine?

Tizanidine hydrochloride is an FDA-approved centrally acting alpha-2 adrenergic agonist indicated for the management of spasticity. The reference product, Zanaflex, was approved in tablet and capsule forms. Generic tizanidine tablets and capsules are widely available in the United States.

Attribute	Tizanidine
Active ingredient	Tizanidine hydrochloride
Drug class	Centrally acting alpha-2 adrenergic agonist
Primary use	Spasticity
Reference product	Zanaflex
Reference sponsor	Acorda Therapeutics, following acquisition of the product from Elan-related commercialization arrangements
FDA dosage forms	Immediate-release tablets and capsules
Common strengths	2 mg, 4 mg, and 6 mg capsule; tablets commonly 2 mg and 4 mg
Administration	Oral
Regulatory status	Genericized; no meaningful remaining reference-product market exclusivity
Key pharmacokinetic issue	Food can materially affect exposure
Primary safety constraints	Sedation, hypotension, bradycardia, liver injury, and CYP1A2-mediated interactions

The FDA label identifies tizanidine as a short-acting drug that is generally dosed at intervals of six to eight hours. Dose titration is important because adverse effects increase with dose. The product is also subject to clinically important interactions with strong CYP1A2 inhibitors, including fluvoxamine and ciprofloxacin.[1]

What excipients are used in tizanidine tablets and capsules?

The reference product uses conventional immediate-release excipients, but generic products can differ materially in formulation composition. These differences create opportunities for lower-risk reformulation, particularly where excipient selection affects disintegration, dissolution, taste, swallowability, or food-related performance.

Typical tablet excipient architecture

The Zanaflex tablet formulation has been described as containing conventional solid oral excipients, including:

• Microcrystalline cellulose
• Lactose
• Stearic acid
• Colloidal silicon dioxide
• Colorants, depending on strength and product presentation

Generic tizanidine tablets may use lactose, mannitol, dibasic calcium phosphate, starch, pregelatinized starch, crospovidone, croscarmellose sodium, sodium starch glycolate, magnesium stearate, and colloidal silicon dioxide. Exact compositions vary by manufacturer and product strength.

The low dose of tizanidine creates a high excipient-to-drug ratio. This increases the importance of blend uniformity, segregation control, content uniformity, and dissolution robustness. A formulation with a 2 mg dose has less active material available to compensate for poor powder flow or uneven distribution.

Typical capsule excipient architecture

Tizanidine capsules generally contain hard gelatin shells and a powder or granulated fill. Excipients may include:

• Lactose or mannitol
• Microcrystalline cellulose
• Silicon dioxide
• Magnesium stearate or another lubricant
• Sodium lauryl sulfate in some formulations
• Capsule colorants and opacifiers

Capsule products may create more room for multiparticulate technologies, taste masking, sprinkle delivery, or modified-release bead systems. They also introduce additional variables, including capsule shell moisture, fill weight, powder density, and shell dissolution.

Why excipient selection matters

Tizanidine has a relatively narrow therapeutic-use window. Formulation changes that alter the rate or extent of absorption can affect sedation, hypotension, and clinical tolerability. Excipients are therefore not limited to manufacturability. They can influence:

• Initial dissolution rate
• Dose uniformity at low strengths
• Gastric dispersion
• Food-related exposure
• Taste and mouthfeel
• Tablet hardness and disintegration
• Stability under humidity
• Compatibility with capsule shells
• Patient adherence

A formulation that claims improved tolerability or a reduced food effect would face a higher regulatory burden than a conventional generic with matching immediate-release performance.

What excipient strategies are most attractive for tizanidine?

The most commercially relevant strategy is to select excipients around a defined product gap rather than to substitute excipients without a clinical objective.

Low-dose content-uniformity strategy

Tizanidine 2 mg creates a classic low-dose formulation challenge. A robust platform can use:

1. Ordered mixing or carrier-based blending.
2. Granulation to reduce segregation.
3. A high-functionality filler with predictable flow.
4. A superdisintegrant selected for rapid release at low tablet mass.
5. Process controls focused on assay uniformity across compression runs.

Direct compression may reduce manufacturing cost, but wet granulation can improve blend uniformity when the active ingredient has poor flow or poor content distribution. The commercial value is strongest when the sponsor can use one platform across 2 mg and 4 mg strengths.

Lactose-free or reduced-lactose products

Lactose is common in immediate-release tablets and capsules. A lactose-free product could target patients with lactose intolerance, institutional formularies with excipient restrictions, and pharmacies seeking simplified product differentiation.

Possible replacement systems include:

• Mannitol for improved mouthfeel
• Microcrystalline cellulose for compactibility
• Dibasic calcium phosphate for density
• Pregelatinized starch for binding and disintegration
• Copovidone or povidone for granulation

The commercial opportunity is limited if the product only removes lactose without improving administration, labeling, supply reliability, or patient access. A lactose-free claim can be useful when combined with a smaller tablet, an orally disintegrating dosage form, or a pediatric formulation.

Orally disintegrating tablet strategy

An orally disintegrating tablet could address patients with dysphagia, spasticity-related disability, or difficulty handling conventional tablets. The formulation would need:

• Rapid disintegration
• Low friability
• Acceptable taste
• Limited hygroscopicity
• Adequate dose uniformity
• Packaging that protects against moisture

Mannitol-based ODT systems are commercially familiar and can provide a cooling mouthfeel. Crospovidone, croscarmellose sodium, or low-substituted hydroxypropyl cellulose can support rapid water penetration. Taste masking is essential because tizanidine can produce an unpleasant oral experience in a rapidly dispersing dosage form.

A tizanidine ODT would likely be more valuable as a 505(b)(2) product if it offers a meaningful administration benefit or a clinically relevant pharmacokinetic advantage. An ANDA approach may be possible if the product can meet applicable product-specific guidance and demonstrate bioequivalence to the reference product.

Oral liquid and concentrated solution strategy

An oral solution is one of the clearest formulation gaps. Tizanidine is dosed in small milligram quantities, making a liquid technically feasible. Potential users include:

• Patients unable to swallow tablets
• Long-term-care residents
• Pediatric or adolescent patients where clinically appropriate
• Patients requiring fine dose titration
• Home-care settings using enteral administration

A liquid formulation would require careful control of:

• Solubility and pH
• Chemical stability
• Microbial preservation
• Container compatibility
• Dose-measuring accuracy
• Taste masking
• Alcohol and sugar content
• Sedimentation or precipitation, if a suspension is used

An alcohol-free, sugar-free, dye-free formulation could create stronger differentiation than a conventional compounded solution. A calibrated oral syringe and low-volume dose presentation would be commercially important because tizanidine doses are small and titrated.

An FDA-approved liquid could compete with pharmacy-compounded products and reduce preparation variability. The regulatory pathway would likely be a 505(b)(2) application unless an ANDA route is specifically available for the proposed product and reference standard.

Sprinkle capsule or mini-tablet strategy

A sprinkle capsule containing coated granules or mini-tablets could address patients who cannot swallow capsules but can take medicine with soft food. The product would require:

• Uniform drug distribution across multiparticulates
• Minimal dose loss during transfer
• Stability in the selected food vehicle
• Acceptable taste after opening
• No premature release or dose dumping
• Clear administration instructions

This format may have greater commercial value than a standard capsule because it can support administration flexibility without requiring a full liquid development program.

How does food affect tizanidine formulation design?

Food effect is one of the central technical barriers in tizanidine development. The FDA labeling states that food increases tizanidine exposure. In clinical pharmacology studies, food increased tizanidine area under the curve by approximately 30% and peak concentration by approximately 33%, while delaying time to peak concentration.[1]

The label also describes differences between tablet and capsule administration under fed and fasted conditions. These differences mean that a new formulation should not be evaluated only through a single fasted bioequivalence study. The sponsor should assess:

• Fasted pharmacokinetics
• Fed pharmacokinetics
• Cmax and AUC
• Early exposure
• Tmax
• Dose proportionality
• Strength comparisons
• In vitro dissolution across pH conditions
• Alcohol dose-dumping risk for modified-release products

A low-risk formulation should preserve the immediate-release profile and avoid excipients that materially alter gastric emptying, intestinal permeability, or dissolution. Lipid-based systems, highly solubilizing surfactant systems, and complex polymer matrices could increase regulatory scrutiny because they may amplify the food effect.

What formulation patents protect tizanidine products?

Tizanidine’s core active-ingredient and conventional immediate-release product protection has largely expired. The commercial landscape is dominated by generic tablets and capsules rather than an active innovator patent estate.

Patent and exclusivity position

Protection category	Current commercial significance
Core compound patent	Expired
Original Zanaflex product exclusivity	Expired
Conventional tablet protection	No meaningful barrier to generic competition
Conventional capsule protection	No meaningful barrier to generic competition
New ODT formulation	Potentially protectable through formulation claims
Oral solution	Potentially protectable through composition, concentration, taste masking, and stability claims
Sprinkle formulation	Potentially protectable through multiparticulate structure and administration claims
Modified-release product	Potentially protectable through release profile, polymer system, and dosing regimen
Method-of-use claims	Potentially available for differentiated populations or dosing regimens, subject to written-description and obviousness risks

Any active patent assessment should be conducted against current USPTO records, FDA Orange Book listings, and relevant international registers. A new sponsor cannot rely on expired compound protection to block generic entry. Commercial protection must come from formulation, device, manufacturing, or clinically differentiated method claims.

What is the Orange Book status of tizanidine?

The Orange Book identifies the FDA-approved reference products and applicable therapeutic-equivalence information for generic competition. Conventional tizanidine tablets and capsules are generally positioned as immediate-release products with AB-rated generic competition where the relevant product-specific requirements are met.[2]

The Orange Book does not create new market exclusivity for a generic sponsor. Its commercial value is in identifying:

• Reference listed drug status
• Approved dosage forms and strengths
• Therapeutic-equivalence ratings
• Patent and exclusivity listings, where applicable
• The regulatory basis for generic competition

A differentiated liquid, ODT, sprinkle, or modified-release product may not fit the same ANDA pathway as a conventional tablet or capsule. The sponsor should determine whether the proposed dosage form has a suitable reference standard or whether a 505(b)(2) application is required.

Which companies are challenging or competing with tizanidine?

Tizanidine competes primarily with generic manufacturers and with alternative antispasticity drugs. The generic field includes multiple manufacturers of tizanidine tablets and capsules, with supply often varying by strength and product presentation.

Direct generic competition

The principal competitive factors are:

• Wholesale acquisition cost
• Pharmacy availability
• Contract manufacturing capacity
• Number of approved strengths
• Tablet versus capsule supply
• Backorder resilience
• Formulary status
• Package size and institutional purchasing terms

A new entrant offering only another 2 mg or 4 mg immediate-release tablet would face limited pricing power unless it has a manufacturing-cost advantage or supply reliability advantage.

Therapeutic competition

Tizanidine competes with:

• Baclofen
• Cyclobenzaprine, although its primary use profile differs
• Methocarbamol
• Carisoprodol, where clinically and legally appropriate
• Dantrolene
• Gabapentin and related agents in selected spasticity or pain settings
• Botulinum toxin products for focal spasticity

Tizanidine’s advantages include short duration and titratability. Its disadvantages include sedation, hypotension, CYP1A2 interactions, and food-related pharmacokinetic variability.

How strong is the patent estate for a new tizanidine formulation?

A conventional tablet or capsule has weak differentiation potential. A well-designed new dosage form can have a moderate patent position if it combines composition, process, and clinical-use claims.

Stronger claim categories

Potentially valuable claims include:

• Specific excipient ratios that produce rapid disintegration
• Taste-masked tizanidine particles
• Stable aqueous solutions at defined pH ranges
• Preservative systems that maintain potency and microbial quality
• Multiparticulate formulations with controlled release
• Sprinkle capsules that retain dose uniformity after opening
• Low-dose tablets with improved content uniformity
• Formulations that reduce fed-versus-fasted variability
• Packaging systems that protect moisture-sensitive dosage forms
• Specific manufacturing processes that produce consistent particle distribution

Weaker claim categories

Claims are generally weaker when they rely on:

• Routine substitution of one filler for another
• Broad lists of conventional excipients
• A dosage form without demonstrated technical benefit
• Simple color or flavor changes
• A broad therapeutic-use claim without clinical differentiation
• A formulation that reproduces the reference product without a measurable advantage

The strongest portfolio would combine composition-of-matter claims for the formulation, manufacturing claims, and narrower use claims supported by pharmacokinetic or adherence data.

What generic entry risks exist for tizanidine?

Generic entry risk is already high for conventional oral products because the active ingredient is old, widely available, and not protected by meaningful remaining exclusivity.

Risk by product type

Product	Generic or follow-on risk	Commercial implication
Standard 2 mg tablet	Very high	Price competition dominates
Standard 4 mg tablet	Very high	Limited differentiation
2 mg, 4 mg, or 6 mg capsule	Very high	Supply and contracting determine share
ODT	Moderate	Administration benefit can support premium pricing
Oral solution	Moderate	Regulatory and stability barriers create space
Sprinkle capsule	Moderate	Device, taste, and dose-delivery execution matter
Modified release	Lower initially	Higher development and clinical risk
Pediatric formulation	Moderate	Labeling and clinical-development requirements remain material
Low-variability fed-state formulation	Moderate	Requires strong pharmacokinetic evidence

A new branded formulation would not be protected from generic competition indefinitely. Once listed patents expire, the product could face an ANDA or 505(b)(2) challenge. Formulation patents must therefore be narrow enough to survive validity challenges but broad enough to cover practical commercial substitutes.

When does tizanidine lose exclusivity?

Tizanidine has already lost the exclusivity that protected the original reference product. The current market should be treated as genericized.

For a new tizanidine product, exclusivity would depend on the regulatory route and the specific innovation:

• A standard ANDA generally does not provide innovative-drug exclusivity.
• A 505(b)(2) product may qualify for three years of marketing exclusivity for certain new clinical investigations essential to approval.
• A new chemical entity pathway is not relevant to tizanidine hydrochloride.
• Orphan exclusivity would require a qualifying orphan indication and would not arise from a routine formulation change.
• Patent protection for a new formulation could extend beyond regulatory exclusivity but would be subject to Paragraph IV challenges.

What licensing deals could support a tizanidine formulation?

Commercial licensing opportunities are more likely to involve formulation platforms, manufacturing technology, or regional distribution than the tizanidine active ingredient itself.

Potential deal structures include:

1. A formulation license for an ODT, liquid, or sprinkle technology.
2. A contract development and manufacturing agreement for low-dose tablets.
3. A regional commercialization license for institutional or long-term-care channels.
4. A co-development agreement covering a 505(b)(2) product.
5. A platform license for taste masking, multiparticulates, or moisture-protective packaging.

The most credible licensing asset would include a reproducible formulation, a defined regulatory pathway, analytical methods, stability data, and a manufacturable commercial process. A concept based only on excipient substitution would have limited licensing value.

What commercial opportunities are available in tizanidine?

Institutional and long-term-care formulations

Long-term-care facilities value dose flexibility, ease of administration, low error rates, and reliable supply. A concentrated oral solution with an oral syringe, or a sprinkle product with clear administration instructions, could address these needs.

Specialty pharmacy and home-care products

Home-care patients may benefit from a low-volume liquid or dose-flexible product. Packaging should support accurate measurement and minimize exposure to light, oxygen, and moisture where relevant.

Pediatric and adolescent use

Tizanidine use in younger patients requires careful regulatory and clinical positioning. A pediatric product could create a meaningful administration advantage, but the sponsor would need age-appropriate dosing evidence, palatability testing, and an appropriate regulatory strategy.

Compounding substitution

An FDA-approved liquid could compete with compounded tizanidine solutions. The value proposition would include validated concentration, preservative control, batch consistency, shelf-life data, and standardized labeling.

Supply-chain differentiation

A sponsor can gain share without a new clinical claim by offering:

• Consistent availability of all strengths
• Domestic or diversified manufacturing
• Fewer excipient supply disruptions
• Reduced tablet weight
• Stable performance under humidity
• Institutional-friendly packaging
• Unit-dose presentations

What manufacturing and IP barriers affect tizanidine products?

Tizanidine itself is a small, established molecule, so active-ingredient sourcing is unlikely to be the principal barrier. The more important barriers are formulation and process control.

Key technical risks include:

• Low-dose content uniformity
• Segregation during blending and transfer
• Lubricant overmixing
• Slow or variable disintegration
• Food-effect differences
• Taste masking failure
• Solution precipitation
• Preservative incompatibility
• Capsule-shell moisture migration
• Stability loss in high humidity
• Scale-up changes in granule size and compression force

Manufacturing patents can provide useful protection when they claim a defined process linked to a measurable product attribute. Process claims alone may be difficult to enforce if the final product does not reveal the manufacturing route.

How does tizanidine compare with baclofen for formulation opportunities?

Factor	Tizanidine	Baclofen
Primary use	Spasticity	Spasticity
Common oral dosage form	Immediate-release tablets and capsules	Immediate-release tablets and oral solution in some markets
Dose profile	Low dose, frequent titration	Higher milligram dose
Key formulation issue	Food effect and CYP1A2 interaction	Dose flexibility and swallowability
ODT opportunity	High	Moderate
Liquid opportunity	High	Existing competition may be stronger
Generic price pressure	High	High
Differentiation route	Food-effect control, taste masking, liquid, sprinkle	Pediatric or liquid convenience, tolerability, delivery systems

Tizanidine has a stronger technical rationale for low-dose ODT and precision-dose products. Baclofen may have a more established liquid-product benchmark, making tizanidine liquid development commercially attractive where the sponsor can improve concentration, palatability, or stability.

Key Takeaways

• Tizanidine is a mature, genericized product with little remaining conventional exclusivity.
• Standard tablets and capsules offer limited commercial upside without cost or supply advantages.
• The strongest excipient opportunities are ODTs, alcohol-free oral liquids, sprinkle capsules, lactose-free products, and low-dose tablets with improved content uniformity.
• Food-related pharmacokinetic variability is the main formulation issue.
• A differentiated product would likely require a 505(b)(2) analysis unless an ANDA pathway is clearly available.
• Formulation patents should focus on measurable technical effects, not routine excipient substitution.
• Institutional, long-term-care, home-care, and compounding-substitution markets offer the clearest commercial targets.
• Generic entry risk is already high for conventional tizanidine dosage forms.

FAQs

Can tizanidine be formulated as a liquid without alcohol?

Yes. An alcohol-free liquid is technically feasible, but development must address solubility, pH, preservative effectiveness, taste masking, container compatibility, and dose-measuring accuracy. A stable solution would generally be more commercially attractive than a suspension.

Is a tizanidine orally disintegrating tablet likely to qualify for 180-day generic exclusivity?

Not automatically. ANDA exclusivity depends on the applicable generic pathway and first-filer status. A genuinely differentiated ODT may instead require a 505(b)(2) application, with regulatory exclusivity determined by the approved clinical and formulation changes.

Which excipient is best for tizanidine taste masking?

No single excipient is universally best. Polymer coating, ion-exchange resins, lipid barriers, and pH-modifying systems are possible approaches. The selected system must preserve rapid release and avoid increasing food-related exposure variability.

Can tizanidine be compounded into an oral suspension?

Compounding pharmacies may prepare tizanidine liquid products, but compounded formulations do not have the same FDA approval, manufacturing controls, or standardized stability package as an approved commercial product. This creates an opportunity for a validated commercial liquid.

Could a modified-release tizanidine product command a premium?

Potentially, but the development burden is high. A modified-release product would need to demonstrate a clinically useful exposure profile while avoiding dose dumping, excessive sedation, hypotension, and unacceptable food effects.

References

1. U.S. Food and Drug Administration. (2023). Zanaflex (tizanidine hydrochloride) prescribing information. FDA.

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

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

4. U.S. Food and Drug Administration. (2024). Inactive ingredient database. FDA.

5. U.S. Food and Drug Administration. (2023). Guidance for industry: Bioequivalence studies with pharmacokinetic endpoints for drugs submitted under an ANDA. FDA.