Drugs Containing Excipient (Inactive Ingredient) DIBUTYL PHTHALATE

Branded drugs containing DIBUTYL PHTHALATE excipient, and estimated key patent expiration / generic entry dates

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
State of Florida DOH Central Pharmacy	ASACOL	mesalamine	53808-0823	DIBUTYL PHTHALATE

Generic drugs containing DIBUTYL PHTHALATE excipient

Company	Ingredient	NDC	Excipient
State of Florida DOH Central Pharmacy	mesalamine	53808-0823	DIBUTYL PHTHALATE

Dibutyl Phthalate Pharmaceutical Excipient Market Dynamics and Financial Trajectory

Last updated: August 4, 2026

Dibutyl phthalate, or DBP, is a legacy pharmaceutical plasticizer used mainly in enteric and film-coating systems. Its pharmaceutical market is structurally declining because of reproductive-toxicity concerns, tightening chemical controls, customer procurement restrictions, and substitution by citrate esters and other non-phthalate plasticizers. DBP remains technically useful in some coating systems, but its commercial value is concentrated in legacy formulations and specialized supply rather than new product development.

No audited public market-size series isolates pharmaceutical-grade DBP from the much larger industrial plasticizer market. Financial analysis therefore depends on regulatory exposure, formulation substitution, supplier concentration, and the number of marketed products that still use DBP.

What is dibutyl phthalate used for in pharmaceuticals?

Dibutyl phthalate is a hydrophobic plasticizer that increases flexibility and reduces brittleness in polymer films. In pharmaceuticals, its historical use has centered on oral solid-dose coatings.

Attribute	Data
Chemical name	Dibutyl phthalate
CAS number	84-74-2
Molecular formula	C16H22O4
Molecular weight	278.35
Primary pharmaceutical function	Plasticizer
Main dosage-form application	Coated tablets, delayed-release tablets, capsules
Typical coating systems	Cellulose-based enteric polymers, methacrylate copolymers, polymeric film coatings
Commercial position	Legacy excipient with declining pharmaceutical demand
Main substitutes	Triethyl citrate, acetyl tributyl citrate, tributyl citrate, acetyl triethyl citrate, polyethylene glycol and other non-phthalate plasticizers

DBP does not provide enteric protection by itself. It modifies the mechanical properties of the coating polymer, improving flexibility, film formation and resistance to cracking. Its use is therefore tied to the formulation design and manufacturing process of the finished dosage form.

How large is the dibutyl phthalate pharmaceutical excipient market?

The pharmaceutical DBP market is a small subset of the global DBP market, which includes plastics, adhesives, sealants, inks, coatings and other industrial applications. Public market reports usually aggregate these uses and do not provide a defensible pharmaceutical-only revenue figure.

The pharmaceutical segment has four financial characteristics:

1. Demand is volume-constrained by formulation substitution.
2. Unit pricing can carry a premium for documented quality and regulatory support.
3. Revenue is concentrated in established products rather than pipeline launches.
4. Industrial volume cannot be used as a proxy for pharmaceutical excipient revenue.

The likely market trajectory is:

Period	Market condition	Financial implication
Historical	DBP used broadly as a coating plasticizer	Higher pharmaceutical volume and wider formulation adoption
Current	Regulatory scrutiny and substitution	Lower demand, weaker volume growth and higher qualification costs
Near term	Continued use in legacy products	Stable residual revenue in approved formulations
Medium term	Reformulation and procurement restrictions	Persistent decline in pharmaceutical volume
Long term	Narrow specialty use or withdrawal from new development	Low and concentrated revenue base

Price increases may occur even as volumes decline. Smaller production runs, quality documentation, batch testing, hazardous-material handling and customer-specific qualification can raise the cost per kilogram. That pricing effect does not indicate market growth.

What regulatory restrictions affect pharmaceutical dibutyl phthalate?

DBP has a high regulatory burden relative to many alternative excipients. The European Chemicals Agency classifies DBP as a substance of very high concern because of reproductive toxicity. The EU classification includes reproductive toxicity Category 1B, with hazard statements relating to fertility and fetal development. DBP is also subject to European chemical-management controls under REACH and CLP frameworks (European Chemicals Agency, n.d.-a).

The principal regulatory effects are:

• Restrictions on certain consumer and article uses under REACH.
• Classification as a reproductive toxicant.
• Supply-chain obligations concerning safety data, labeling and exposure controls.
• Increased scrutiny for use in medicinal products, especially pediatric and pregnancy-related products.
• Customer policies that prohibit or discourage phthalate-containing materials even where a specific pharmaceutical use remains legally possible.
• State-level disclosure and chemical-warning exposure in the United States, including California Proposition 65 treatment for reproductive toxicity.

The regulatory distinction is important. A chemical may remain technically usable in a pharmaceutical formulation while becoming commercially unattractive because manufacturers, hospitals, retailers or contract development organizations impose stricter internal standards.

What is the FDA status of dibutyl phthalate as an excipient?

DBP has a historical presence in pharmaceutical formulation practice and is addressed through FDA inactive-ingredient and excipient frameworks. The FDA Inactive Ingredient Database is the principal public source for evaluating prior use in approved drug products, dosage forms and routes of administration (U.S. Food and Drug Administration, n.d.-a).

FDA status does not operate as a blanket approval of every DBP use. Sponsors must establish that the proposed quantity, route, dosage form and patient exposure are acceptable for the specific product. A prior listing can support regulatory precedent, but it does not eliminate the need for product-specific review.

For a new drug application or abbreviated new drug application, the regulatory issues include:

• The quantity of DBP per unit dose.
• Maximum daily patient exposure.
• Route and duration of administration.
• Intended population, particularly children and pregnant patients.
• Impurity profile and residual solvents.
• Extractables and leachables from manufacturing equipment or packaging.
• Compatibility with the coating polymer and active ingredient.
• Justification for not selecting a lower-concern substitute.

FDA’s excipient review pathway is therefore permissive in principle but commercially restrictive in practice. Sponsors seeking a new formulation generally have stronger incentives to use citrate-based plasticizers unless DBP provides a material technical advantage.

What does the European regulatory framework mean for DBP-containing medicines?

European regulators have specifically addressed phthalates in medicinal products. The European Medicines Agency has identified reproductive-toxicity concerns and recommended a benefit-risk assessment for phthalates used as excipients. The assessment becomes more sensitive for chronic treatment, pediatric use, pregnancy and high-dose exposure (European Medicines Agency, 2005).

Marketing authorization holders must also comply with European excipient-labeling requirements. Excipients with a recognized effect require appropriate information in the product information and package leaflet. The European Commission guideline on excipients in labeling provides the framework for these disclosures (European Commission, 2017).

The commercial result is a higher reformulation threshold in Europe than in markets where excipient disclosure and chemical restrictions are less burdensome. A DBP-containing product may remain approved, but its manufacturer can face:

• Additional labeling obligations.
• Questions from health authorities during variation procedures.
• Tender or hospital exclusion.
• Customer pressure to remove phthalates.
• Higher pharmacovigilance and lifecycle-management costs.

What formulations are protected or dependent on dibutyl phthalate?

DBP is not normally protected as an active pharmaceutical ingredient. Its commercial relevance lies in formulation know-how, coating composition and manufacturing parameters.

Enteric-coated tablets

DBP has been used with cellulose acetate phthalate, cellulose acetate trimellitate, hydroxypropyl methylcellulose phthalate and methacrylic acid copolymers. The plasticizer affects:

• Film flexibility.
• Minimum film-forming temperature.
• Crack resistance.
• Adhesion to the tablet core.
• Dissolution behavior after exposure to gastric and intestinal media.
• Coating uniformity and process yield.

Delayed-release capsules

DBP can be incorporated into polymeric capsule coatings or applied to multiparticulate systems. The commercial risk is higher where the coating process is tightly validated and substitution could change dissolution performance.

Film-coated immediate-release products

Use in non-enteric film coating is technically possible but less defensible where alternative plasticizers provide acceptable performance. This segment is more exposed to replacement.

How strong is the patent estate for dibutyl phthalate?

DBP has no meaningful modern composition-of-matter exclusivity as a pharmaceutical excipient. The molecule was disclosed and used decades ago, making new molecule-level patent protection commercially irrelevant.

Patent value can still arise in:

• Specific enteric-coating compositions.
• Ratios of DBP to polymer and solvent.
• Coating processes.
• Multiparticulate delivery systems.
• Release profiles.
• Stability improvements.
• Combination coatings using DBP with other plasticizers.

These patents protect a formulation or process, not DBP itself. Their practical strength depends on whether the claims require DBP or merely permit it as one option. Broad claims that list numerous plasticizers may provide limited exclusionary value. Narrow claims tied to a defined polymer ratio, dissolution profile or manufacturing parameter can remain relevant but are vulnerable to design-around.

A product-specific patent review should distinguish:

Patent category	Relevance to DBP market
DBP composition patents	No meaningful current exclusivity expected
Enteric-coating composition patents	Potentially relevant to legacy products
Manufacturing-process patents	May restrict a particular coating process
Method-of-use patents	Usually weak unless tied to a defined release profile
Packaging or compatibility patents	Relevant to stability and extractables
Formulation know-how	Often more important than issued patent rights

Are there Paragraph IV challenges involving dibutyl phthalate?

Paragraph IV litigation generally concerns patents listed in the FDA Orange Book for an approved drug. DBP itself is an excipient and is not an Orange Book-listed active ingredient. It does not have an independent Orange Book exclusivity period.

A generic applicant may challenge a branded product patent that covers a DBP-containing formulation, but the litigation would concern the drug product’s formulation, method of use or release profile. The challenge would not ordinarily be framed as a challenge to DBP as a chemical substance.

The relevant generic-entry risks are:

• A non-infringing formulation that replaces DBP.
• A coating system that uses a different plasticizer.
• A Paragraph IV certification against a formulation patent.
• A product-specific settlement delaying generic launch.
• A regulatory requirement to demonstrate bioequivalence after excipient substitution.

Which companies are exposed to DBP substitution?

Exposure is distributed across four groups:

1. Excipient manufacturers and distributors with pharmaceutical-grade DBP inventory.
2. Contract coating and contract manufacturing organizations.
3. Originator companies with legacy DBP-containing products.
4. Generic manufacturers whose abbreviated applications reference an established DBP-containing product.

The highest exposure is likely among suppliers that lack a broad non-phthalate portfolio. A supplier selling triethyl citrate, acetyl tributyl citrate or related plasticizers can convert regulatory pressure into substitution revenue. A supplier dependent on DBP alone faces volume erosion and possible customer qualification losses.

No material public licensing transactions are specifically associated with pharmaceutical DBP. Commercial relationships are more likely to consist of supply agreements, distributor arrangements, technical-service contracts and customer-specific qualification work.

How does DBP compare with alternative pharmaceutical plasticizers?

Plasticizer	Relative market direction	Main advantage	Main limitation
Dibutyl phthalate	Declining	Established performance and historical process knowledge	Reproductive-toxicity and procurement concerns
Triethyl citrate	Growing replacement candidate	Broad acceptance and non-phthalate profile	May require coating-process adjustment
Acetyl tributyl citrate	Replacement candidate	Good flexibility and hydrophobicity	Cost and formulation-specific compatibility
Tributyl citrate	Established alternative	Useful film-plasticizing performance	May alter release and coating behavior
Polyethylene glycol	Used selectively	Familiar excipient and processing flexibility	Hygroscopicity and migration concerns
Diethyl phthalate	Limited substitute	Similar chemical family and process familiarity	Does not eliminate all phthalate concerns

Substitution is not a simple one-for-one change. Sponsors must reassess coating dispersion, spray rate, drying conditions, film morphology, dissolution, stability and bioequivalence. That creates switching costs and explains why DBP can remain in older products despite a declining strategic position.

What generic launch scenarios exist for DBP-containing products?

Generic entry can follow three paths:

Direct formulation match

The generic uses DBP at a level comparable to the reference product. This may simplify formulation development but preserves regulatory and procurement concerns.

Non-phthalate formulation

The generic replaces DBP with a citrate ester or another plasticizer. This can improve commercial acceptability but may require additional formulation work and comparative dissolution testing.

Design-around coating

The generic uses a different polymer system or a coating process that achieves the same release profile without DBP. This reduces dependence on the reference product’s formulation patents and may support a stronger lifecycle position.

For originators, DBP-containing products face a dual risk: patent expiry can permit conventional generic entry, while pre-expiry reformulation may be needed to avoid future regulatory or customer pressure. For generic companies, the main barrier is technical equivalence, not access to DBP itself.

What is the financial trajectory for pharmaceutical DBP?

The base-case trajectory is declining pharmaceutical revenue with intermittent price support.

Revenue drivers include:

• Legacy product retention.
• Long qualification cycles.
• Limited supplier competition for validated grade.
• Customer reluctance to change a stable coating process.
• Continued industrial-scale manufacturing capacity.

Revenue risks include:

• Reformulation to citrate plasticizers.
• New-pharmaceutical-development exclusion.
• EU and U.S. chemical-risk controls.
• Hospital and retailer procurement policies.
• Product discontinuation after generic entry.
• Higher analytical and documentation costs.
• Supplier exit from pharmaceutical grade.

The most probable financial pattern is a shrinking volume pool, with revenue concentrated in a smaller number of customers and products. Margin performance will depend on whether suppliers can maintain pharmaceutical-grade pricing and sell replacement excipients into the same accounts.

What is the investment and commercial outlook?

DBP is a defensive legacy-excipient opportunity rather than a growth market. Attractive economics would require one of three conditions:

• A protected or difficult-to-reformulate legacy product base.
• A supply position in a validated pharmaceutical grade.
• A broader excipient portfolio that captures substitution demand.

A standalone DBP strategy has weak long-term growth characteristics. The stronger commercial strategy is portfolio migration: retain DBP supply for existing products while expanding into citrate esters, cellulose derivatives, methacrylate polymers and coating-service capabilities.

Key Takeaways

• DBP is a legacy pharmaceutical plasticizer used mainly in enteric and film coatings.
• Its pharmaceutical market is declining because of reproductive-toxicity concerns and non-phthalate substitution.
• Public sources do not provide a reliable standalone pharmaceutical DBP revenue figure.
• FDA and European regulatory frameworks allow product-specific assessment but increase exposure, labeling and lifecycle-management costs.
• DBP has no meaningful current molecule-level patent exclusivity.
• Formulation and process patents may affect individual products, but they do not create broad DBP market protection.
• Triethyl citrate and acetyl tributyl citrate are the principal commercial substitution pathways.
• Revenue is likely to remain concentrated in approved legacy products and validated supply relationships.
• The strongest supplier strategy is to use DBP as a declining base product while expanding replacement-excipient sales.

FAQs

Is dibutyl phthalate still used in prescription medicines?

Yes. It may remain in certain approved coated tablets, capsules and delayed-release products, although new formulation development increasingly avoids it.

Is pharmaceutical-grade dibutyl phthalate different from industrial DBP?

Pharmaceutical-grade material requires tighter controls over identity, purity, impurities, residual solvents, documentation and change control. The chemical substance is the same, but the quality system and specification package differ.

Can a company reformulate a DBP-containing drug without conducting new clinical trials?

Possibly, depending on the product, dosage form, regulatory pathway and effect of the excipient change. Dissolution, stability, comparability and bioequivalence requirements determine the filing burden.

Does DBP create a biosimilar risk?

No direct biosimilar risk exists because DBP is a small-molecule excipient, not a biologic active ingredient. It can appear as a formulation or manufacturing issue in biologic products, but biosimilar exclusivity does not attach to DBP.

Does DBP have an FDA exclusivity period?

No. DBP is not an active pharmaceutical ingredient with independent FDA market exclusivity. Any relevant exclusivity would arise from the finished drug product, regulatory exclusivity or product-specific patents.

References

European Chemicals Agency. (n.d.-a). Dibutyl phthalate: Substance information. https://echa.europa.eu/

European Commission. (2017). Guideline on the details of the various categories of variations, on the operation of the procedures laid down in Chapters II, IIa, III and IV of Commission Regulation (EC) No 1234/2008 of 24 November 2008 concerning the examination of variations to the terms of marketing authorisations for medicinal products for human use and veterinary medicinal products and on the documentation to be submitted pursuant to those procedures. Official Journal of the European Union.

European Medicines Agency. (2005). Position paper on the use of phthalates in human medicinal products. https://www.ema.europa.eu/

U.S. Food and Drug Administration. (n.d.-a). Inactive Ingredient Database. https://www.accessdata.fda.gov/scripts/cder/iig/index.cfm

U.S. Food and Drug Administration. (n.d.-b). Inactive ingredients in approved drug products. https://www.fda.gov/drugs/drug-approvals-and-databases/inactive-ingredients-approved-drug-products

U.S. Pharmacopeial Convention. (n.d.). USP-NF: Pharmaceutical excipients and compendial standards. https://www.usp.org/η