List of Excipients in Branded Drug ELIDEL

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Bausch Health US LLC	ELIDEL	pimecrolimus	0187-5102	BENZYL ALCOHOL
Bausch Health US LLC	ELIDEL	pimecrolimus	0187-5102	CETYL ALCOHOL
Bausch Health US LLC	ELIDEL	pimecrolimus	0187-5102	CITRIC ACID MONOHYDRATE

Elidel Excipient Strategy and Commercial Opportunities for Pimecrolimus Cream 1%

Last updated: August 5, 2026

Elidel is a topical pimecrolimus 1% cream approved for mild-to-moderate atopic dermatitis. Its commercial position depends less on active-ingredient exclusivity and more on vehicle performance, tolerability, generic substitution, pediatric usability, and differentiation from topical corticosteroids and topical calcineurin inhibitors.

The primary opportunity is a technically improved pimecrolimus cream or alternative topical delivery system with lower irritation, better skin feel, improved stability, reduced preservative burden, or more convenient dosing. A reformulation would need to preserve pimecrolimus solubilization and dermal delivery while avoiding a new safety concern or an overly complex regulatory pathway.

What is Elidel and how is it formulated?

Elidel contains pimecrolimus at a concentration of 10 mg/g, equivalent to 1% w/w. It is indicated for short-term and intermittent long-term treatment of mild-to-moderate atopic dermatitis in patients aged 2 years and older who are not adequately responsive to, or cannot use, topical corticosteroids.[1]

The FDA-listed vehicle contains the following excipients:

Excipient	Likely formulation function
Cetyl alcohol	Emollient, consistency agent, co-emulsifier
Stearyl alcohol	Emollient, viscosity modifier, consistency agent
Mono- and diglycerides	Emulsifier and texture modifier
Propylene glycol	Solvent, humectant, penetration-supporting excipient
Sodium cetostearyl sulfate	Anionic emulsifier
Benzyl alcohol	Preservative and solvent
Citric acid	pH adjustment
Sodium hydroxide	pH adjustment
Purified water	Aqueous phase

The formulation is an oil-in-water cream designed to deliver a highly lipophilic macrolactam active ingredient to the skin. The vehicle must balance drug solubilization, spreadability, skin residence time, cosmetic acceptability, and controlled dermal penetration.

What excipient strategy supports pimecrolimus delivery?

Pimecrolimus has limited aqueous solubility and requires a vehicle capable of maintaining the drug in a dissolved or finely dispersed state during manufacture, storage, and application. The commercial formulation uses a mixed emollient-emulsifier system rather than a simple aqueous gel.

Solubilization and precipitation control

Propylene glycol is the principal multifunctional excipient in the labeled composition. It can contribute to pimecrolimus solubilization and may increase hydration of the stratum corneum. Its level must be controlled because higher concentrations can increase stinging or irritation, especially on inflamed or pediatric skin.

A reformulation strategy could evaluate:

• Propylene glycol reduction or replacement.
• Polyethylene glycol derivatives.
• Diethylene glycol monoethyl ether, subject to regulatory and tolerability review.
• Transcutol-type solvents.
• Glycol and fatty ester combinations.
• Lipid-based microemulsions.
• Cyclodextrin-assisted systems, although compatibility and loading may limit feasibility.

The key development risk is precipitation after dilution by skin moisture or during temperature cycling. A formulation that initially appears clear may crystallize during storage or after application.

Emulsion architecture

Cetyl alcohol, stearyl alcohol, mono- and diglycerides, and sodium cetostearyl sulfate provide the structural framework for the cream. This combination controls viscosity, phase stability, application characteristics, and drug distribution.

Potential commercial improvements include:

• A lower-viscosity cream for rapid spreading.
• A richer cream for xerotic or lichenified lesions.
• A nonionic emulsifier system with lower irritation potential.
• A lamellar liquid-crystal vehicle that improves skin feel and barrier compatibility.
• A preservative-minimized system for sensitive skin.
• A pump or airless package that reduces contamination and dosing variability.

Replacing the anionic emulsifier may improve tolerability, but it can also alter emulsion stability and pimecrolimus release. Any substitute must be evaluated against the reference product for assay, impurities, particle size, rheology, in vitro release, and skin permeation.

Irritation and sensitization management

Benzyl alcohol is a functional preservative, but it can be commercially relevant in pediatric and sensitive-skin positioning. Removing or reducing benzyl alcohol may support a "sensitive skin" product claim, but microbial protection becomes more difficult.

Potential alternatives include:

• Phenoxyethanol.
• Organic acid preservation systems.
• Benzyl alcohol reduction with improved packaging.
• Low-water or anhydrous systems.
• Single-use or unit-dose packaging.

A preservative-free or low-preservative pimecrolimus product would need a robust antimicrobial effectiveness program and container-closure strategy. The regulatory value would be greatest if the change reduced burning, stinging, or contact sensitization without reducing shelf life.

What patents protect Elidel and pimecrolimus cream?

Elidel's original intellectual-property position included patents covering pimecrolimus and pharmaceutical compositions. Historically cited U.S. patents include U.S. Patent No. 5,262,435 and U.S. Patent No. 6,423,728, associated with pimecrolimus or related pharmaceutical compositions.[2,3]

IP category	Historical relevance	Current commercial effect
Pimecrolimus compound patents	Protected the active ingredient and related ascomycin derivatives	Historical protection has expired or is no longer the principal barrier to U.S. generic entry
Cream composition patents	Covered formulation and pharmaceutical composition concepts	May still influence design-around analysis in particular jurisdictions
Method-of-use claims	Covered treatment of inflammatory skin disorders	Narrower commercial value where generic labels omit protected indications
Manufacturing and process know-how	May protect mixing, particle control, stability, or scale-up practices	Can remain commercially important even after patent expiry
Packaging and device claims	Potentially cover airless pumps, dosing systems, or specialty presentations	Relevant to differentiated reformulations

The commercial barrier today is primarily formulation execution, regulatory comparability, manufacturing cost, and physician or payer adoption. Compound-level exclusivity is not the main source of value.

What is the FDA regulatory and Orange Book status of Elidel?

Elidel received FDA approval in December 2001 as a prescription topical product.[1] The reference product is a cream containing pimecrolimus 1%.

The original U.S. regulatory exclusivity periods have expired. Pediatric exclusivity and new chemical entity exclusivity therefore do not provide a current barrier to generic development. The relevant pathway for a conventional generic cream is an abbreviated new drug application supported by pharmaceutical equivalence and bioequivalence evidence appropriate for a topical product.

For topical creams, FDA review can involve more than matching active ingredient strength. A generic sponsor must control:

• Qualitative and quantitative composition.
• Drug content and uniformity.
• Globule or particle distribution, where relevant.
• Rheology and viscosity.
• In vitro release.
• Microbial quality.
• Preservative effectiveness.
• Physical and chemical stability.
• Container-closure performance.

The Orange Book historically linked the reference product to patent information submitted by the innovator. Because Orange Book entries and listing statuses can change, current status must be evaluated against the FDA’s live Orange Book data and patent-listing records rather than historical patent summaries.[4]

When did Elidel lose exclusivity?

Elidel lost the commercial protection associated with its original regulatory exclusivity years ago. The principal compound and composition patents associated with the product were also time-limited. Generic pimecrolimus cream development is therefore legally feasible in the United States, subject to any jurisdiction-specific patent claims and regulatory requirements.

The main exclusivity timeline is:

Milestone	Date or status
FDA approval of Elidel	December 2001
New chemical entity exclusivity	Expired
Pediatric exclusivity	Expired
Original compound patent protection	Expired
Generic development	Legally and commercially established
Current opportunity	Differentiated generic, reformulated product, or licensed regional commercialization

Which companies are challenging Elidel exclusivity?

Generic pharmaceutical companies have pursued pimecrolimus cream products after expiry of the core exclusivity position. The relevant competitive set includes companies with dermatology manufacturing capabilities, topical semisolid development platforms, and established pharmacy distribution.

A Paragraph IV challenge would be relevant only where a listed patent remains active and the applicant certifies that the patent is invalid, unenforceable, or not infringed. For an old topical product such as Elidel, the more important competitive question is whether a generic applicant can demonstrate sufficient product sameness and obtain approval without inheriting unresolved formulation or patent disputes.

A commercial review should distinguish:

1. ANDA applicants challenging listed patents.
2. Approved generic suppliers.
3. Authorized generic or licensed suppliers.
4. Companies developing non-generic reformulations.
5. Regional manufacturers operating outside the U.S. reference-product framework.

What formulation patents could support a new pimecrolimus product?

A new formulation has stronger patent potential when it produces a measurable technical effect rather than simply substituting one conventional excipient for another.

Potential claim areas include:

Low-irritation formulations

Claims could focus on reduced propylene glycol, elimination of benzyl alcohol, controlled pH, or a specific emulsifier system. The commercial case would require comparative tolerability data.

Enhanced dermal delivery

A microemulsion, nanoemulsion, lipid vesicle, or structured-lipid vehicle could support claims directed to increased deposition in the epidermis or reduced systemic exposure. The formulation must avoid excessive penetration that could increase safety concerns.

Anhydrous or low-water systems

These systems may improve chemical stability and reduce microbial risk. They could also permit novel packaging and longer in-use stability. Their limitations include poor skin feel, difficult spreading, and possible crystallization of pimecrolimus.

Pediatric and sensitive-skin products

A product with reduced sting, lower fragrance or allergen exposure, and improved dosing convenience could target children and patients with facial or intertriginous atopic dermatitis.

Combination products

Combining pimecrolimus with barrier-supportive ingredients, such as ceramide systems or humectants, could improve product positioning. Combination claims face added regulatory and patent complexity, particularly if the second active ingredient changes the product’s therapeutic classification.

What commercial opportunities exist for Elidel excipients?

The strongest commercial opportunities are in platform reformulation and contract development rather than commodity excipient supply.

Opportunity	Commercial rationale	Main barrier
Preservative-reduced cream	Sensitive-skin and pediatric differentiation	Microbial control and shelf life
Lower-sting vehicle	Addresses application discomfort	Requires comparative clinical or tolerability evidence
Airless pump packaging	Reduces contamination and dosing variation	Device cost and patient acceptance
Generic-equivalent cream	Access to established prescription demand	Price erosion and pharmacy substitution
Higher-cosmetic-acceptability cream	May improve adherence	Must preserve bioequivalence and drug release
Regional licensing	Enables local manufacturing and distribution	Fragmented regulatory and patent requirements
Dermatology co-development	Uses existing topical manufacturing platforms	Limited differentiation without clinical data

Excipient suppliers can capture value through prequalified premixes, validated preservative systems, specialty emulsion bases, and formulation-development partnerships. A supplier that offers a complete pimecrolimus-compatible vehicle, stability package, and scale-up process has more strategic value than one selling a single conventional excipient.

How does Elidel compare with Protopic and topical corticosteroids?

Elidel competes primarily with tacrolimus ointment, marketed as Protopic, and with topical corticosteroids.

Product class	Active ingredient	Dosage form	Commercial strength	Key limitation
Elidel	Pimecrolimus	1% cream	Nonsteroidal cream with favorable cosmetic profile	Burning or stinging; generic price pressure
Protopic	Tacrolimus	Ointment	Stronger option for some patients and body sites	Greasy vehicle and application discomfort
Topical corticosteroids	Multiple agents	Creams, ointments, lotions, foams	Broad potency range and low cost	Atrophy and other class-related concerns with prolonged use
Barrier products	Ceramides, petrolatum, humectants	Multiple topical forms	OTC access and adjunctive use	Do not replace anti-inflammatory therapy in active disease

Elidel’s cream vehicle is a commercial advantage over an ointment for patients who prioritize rapid absorption and less residue. A reformulated product should preserve that advantage while reducing sting and improving application to the face, neck, and skin folds.

What generic entry risks exist for pimecrolimus cream?

Generic entry creates several risks for the reference product and for reformulation investors:

• Pharmacy substitution can rapidly reduce price.
• Payers may place multiple generic suppliers in preferred positions.
• A reformulation may fail to achieve meaningful clinical differentiation.
• Novel excipients can trigger additional safety or regulatory review.
• A formulation that changes dermal delivery may require more extensive evidence.
• A low-cost generic can undercut premium positioning.
• Existing clinical familiarity with the reference product may limit switching unless the new product improves tolerability or convenience.

The most defensible strategy is a staged program: first develop a compositionally simple generic-equivalent product, then pursue a differentiated vehicle or delivery system only if it produces a measurable patient benefit.

What patent litigation and settlement issues affect Elidel?

Elidel’s principal litigation risk was concentrated around historical patent challenges as generic companies approached market entry. Once core patents and regulatory exclusivities expired, the litigation value declined substantially.

Settlement agreements involving old dermatology products can still affect launch timing, authorized-generic rights, or regional commercialization, but their commercial impact depends on the specific agreement. No current settlement should be assumed to restrict a new pimecrolimus formulation without review of the relevant court docket, patent records, and licensing documents.

How strong is the Elidel patent estate?

The historical estate was strong enough to protect the original product during its exclusivity period, but it is now weak as a barrier to ordinary generic entry. Its residual value is concentrated in:

• Unexpired jurisdiction-specific formulation claims, if any.
• Manufacturing know-how.
• Stability data and process controls.
• Brand recognition.
• Regulatory familiarity.
• Potential licensing rights in selected markets.

A new entrant should not rely on broad pimecrolimus composition claims. Patent value is more likely to arise from a narrow, data-supported vehicle, packaging system, manufacturing process, or use claim.

Key Takeaways

• Elidel is a pimecrolimus 1% oil-in-water cream for atopic dermatitis.
• Its excipient system uses propylene glycol, fatty alcohols, mono- and diglycerides, sodium cetostearyl sulfate, benzyl alcohol, and pH adjusters.
• The principal commercial opportunity is a differentiated topical vehicle, not renewed compound exclusivity.
• Preservative reduction, lower sting, improved cosmetic acceptability, and airless packaging are the most credible differentiation themes.
• Generic pimecrolimus cream faces substantial price competition.
• A formulation patent should be tied to measurable performance, tolerability, stability, or delivery benefits.
• The strongest development pathway is a low-complexity generic-equivalent product followed by targeted reformulation.
• Current Orange Book listings, patent status, and Paragraph IV exposure require review of live FDA and court records.

FAQs

Is pimecrolimus cream still commercially attractive after generic entry?

Yes, but primarily through low-cost manufacturing, regional licensing, differentiated packaging, or an improved vehicle. A conventional branded copy has limited pricing power.

Can benzyl alcohol be removed from an Elidel formulation?

It can be evaluated, but removal requires an alternative microbial-control strategy, packaging assessment, stability testing, and preservative-effectiveness data.

What excipient is most important for pimecrolimus solubilization?

Propylene glycol is the key multifunctional solvent in the labeled cream, although the full emulsion system controls pimecrolimus distribution and release.

Would a pimecrolimus ointment have commercial value?

Potentially, particularly for very dry or lichenified lesions. It would compete directly with tacrolimus ointment and would need a clear tolerability, delivery, or adherence advantage.

Can a pimecrolimus cream qualify as an authorized generic?

An authorized generic pathway may be possible through the relevant NDA holder or licensee, but the commercial structure depends on rights, manufacturing arrangements, labeling, and current market authorization.

References

1. U.S. Food and Drug Administration. (2023). Elidel (pimecrolimus) cream, 1% prescribing information. FDA.

2. U.S. Patent No. 5,262,435. (1993). Ascomycin derivatives. U.S. Patent and Trademark Office.

3. U.S. Patent No. 6,423,728. (2002). Pharmaceutical compositions containing ascomycin derivatives. U.S. Patent and Trademark Office.

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