TERRAMYCIN W/ POLYMYXIN B SULFATE Drug Patent Profile

Which patents cover Terramycin W/ Polymyxin B Sulfate, and what generic alternatives are available?

Terramycin W/ Polymyxin B Sulfate is a drug marketed by Casper Pharma Llc and is included in one NDA.

The generic ingredient in TERRAMYCIN W/ POLYMYXIN B SULFATE is oxytetracycline hydrochloride; polymyxin b sulfate. There are thirty-six drug master file entries for this compound. Additional details are available on the oxytetracycline hydrochloride; polymyxin b sulfate profile page.

Summary for TERRAMYCIN W/ POLYMYXIN B SULFATE

US Patents:	0
Applicants:	1
NDAs:	1
DailyMed Link:	TERRAMYCIN W/ POLYMYXIN B SULFATE at DailyMed

US Patents and Regulatory Information for TERRAMYCIN W/ POLYMYXIN B SULFATE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Casper Pharma Llc	TERRAMYCIN W/ POLYMYXIN B SULFATE	oxytetracycline hydrochloride; polymyxin b sulfate	OINTMENT;OPHTHALMIC	061015-001	Approved Prior to Jan 1, 1982		DISCN	No	No

Terramycin With Polymyxin B Sulfate: Market Dynamics, Financial Trajectory, and Patent Risk

Last updated: August 5, 2026

Terramycin with Polymyxin B Sulfate is a mature veterinary ophthalmic ointment containing oxytetracycline hydrochloride and polymyxin B sulfate. The product is associated with Zoetis and is approved for veterinary use in several animal species. Its commercial position depends more on brand recognition, veterinary distribution, manufacturing reliability, and clinical familiarity than on patent exclusivity.

Product-level sales are not separately disclosed by Zoetis. Financial analysis therefore relies on Zoetis’ animal-health results, product maturity, regulatory records, and the competitive structure of veterinary ophthalmic anti-infectives.

What is Terramycin with Polymyxin B Sulfate?

Terramycin Ophthalmic Ointment contains two antibacterial ingredients:

Attribute	Product information
Brand	Terramycin
Active ingredients	Oxytetracycline hydrochloride and polymyxin B sulfate
Dosage form	Sterile ophthalmic ointment
Primary market	Veterinary medicine
Manufacturer or sponsor	Zoetis Inc.
FDA pathway	New Animal Drug Application
US application	NADA 8-763
Major species on labeling	Dogs, cats, horses, cattle, and sheep
Administration	Topical ophthalmic use
Regulatory classification	Veterinary prescription product in the United States
Patent position	No material current patent exclusivity identified in public regulatory materials

The product is used for bacterial ocular infections and conditions involving susceptible organisms. Its dual-antibiotic formulation gives it a broad historical use profile, but it competes against newer ophthalmic antibiotics and other combination ointments.

The FDA-approved product is an animal drug, not a human prescription medicine. It should not be analyzed through the same regulatory framework as a human product listed in the FDA Orange Book. Its relevant approval information is maintained through the FDA animal-drug system and the FDA Green Book framework.[1][2]

Who manufactures Terramycin ophthalmic ointment?

Zoetis is the principal company associated with the current US Terramycin Ophthalmic Ointment product. Zoetis is the largest global animal-health company by revenue and markets products across companion-animal and livestock categories.

The company does not report Terramycin revenue as a separate line item. Its public reporting aggregates products into broader therapeutic and species categories. This prevents a reliable calculation of:

• Annual Terramycin revenue
• Product-level gross margin
• Market share
• Customer concentration
• Regional sales
• Product-specific growth rates

Terramycin is commercially small relative to Zoetis’ major products, including parasiticides, monoclonal antibodies, vaccines, dermatology products, and livestock medicines.

What is the financial trajectory for Terramycin?

The product is best characterized as a mature, low-growth or stable branded veterinary medicine rather than a growth driver. Its revenue trajectory is likely influenced by unit retention, price increases, channel availability, and veterinary prescribing patterns.

Zoetis reported the following consolidated revenue:

Fiscal year	Zoetis revenue	Year-over-year direction
2022	Approximately $8.1 billion	Growth
2023	Approximately $8.5 billion	Growth
2024	Approximately $9.3 billion	Growth

These figures represent the entire Zoetis business, not Terramycin.[3][4] The financial performance of the company does not provide a direct valuation for the ophthalmic ointment.

Revenue exposure is likely immaterial to Zoetis

Terramycin is a legacy topical product. Its financial importance to Zoetis is likely limited because:

1. The dosage form is low-cost and locally administered.
2. The product has no reported exclusivity premium.
3. Veterinary ophthalmic products are a small portion of the animal-health market.
4. Multiple substitute products are available.
5. Zoetis does not disclose the product as a material reporting unit.

The product can still have strategic value. A mature brand may retain veterinary trust, support distributor relationships, and provide recurring sales without substantial clinical-development expense. Those attributes can produce positive contribution margins even when absolute revenue is modest.

When does Terramycin lose exclusivity?

Terramycin’s original regulatory and patent exclusivity expired decades ago. The product does not appear to have a current US patent barrier that would prevent competing veterinary ophthalmic products from entering the market.

Exclusivity category	Current assessment
Original composition patent	Expired
Original formulation patent	No current enforceable exclusivity identified
FDA new-animal-drug exclusivity	Expired
Pediatric exclusivity	Not applicable
Orphan-drug exclusivity	Not identified
Human Orange Book exclusivity	Not applicable
Veterinary patent-term extension	Not identified
Trademark protection	Potentially relevant to the Terramycin brand name

The key commercial distinction is between patent protection and brand protection. Zoetis may retain trademark rights and a recognized label, but those rights do not prevent competitors from selling other products containing the same or comparable antibacterial ingredients.

What patents protect Terramycin with Polymyxin B Sulfate?

No current US patent estate materially protecting the marketed Terramycin ophthalmic ointment has been identified in the public FDA and company materials reviewed for this analysis.

The likely patent position is:

Patent category	Risk assessment
Oxytetracycline composition patent	Historical and expired
Polymyxin B composition patent	Historical and expired
Dual-active formulation patent	No active product-specific patent identified
Sterile ointment manufacturing patent	No publicly identified blocking patent
Container or tube patent	Unlikely to create meaningful market exclusivity
Method-of-use patent	No current product-specific patent identified
Trademark	Brand differentiation remains possible

The absence of a blocking patent does not eliminate commercial barriers. Sterile ophthalmic production requires validated manufacturing, contamination controls, stability testing, appropriate packaging, and regulatory compliance. Those requirements can deter smaller entrants even when the formulation is technically old.

What is the Orange Book status of Terramycin?

Terramycin is not expected to have an FDA Orange Book listing because the Orange Book covers approved human drugs. Veterinary products are handled through the FDA Center for Veterinary Medicine and related animal-drug databases.

The relevant regulatory records are:

• FDA animal-drug approval records
• The FDA Green Book
• Zoetis’ approved product labeling
• State veterinary-prescription requirements
• Manufacturing and quality requirements applicable to sterile veterinary products

The product’s veterinary status also means that human-drug generic-substitution rules do not directly determine competitive entry. A competing veterinary product generally requires its own regulatory basis rather than an ordinary human ANDA pathway.

Are there Paragraph IV challenges to Terramycin?

No meaningful Paragraph IV litigation risk has been identified. Paragraph IV certifications apply to patents listed for approved human drugs in the Orange Book. Terramycin is a veterinary product and does not occupy the standard human ANDA-Paragraph IV framework.

Competitive entry would more likely involve:

• A separate animal-drug application
• A permitted copy or equivalent veterinary product pathway
• A different ophthalmic antibiotic product
• Compounding or veterinary pharmacy channels, subject to applicable rules
• Importation and distribution of products approved in other jurisdictions

The absence of Paragraph IV litigation reduces legal-delay risk but also confirms that the product does not have a modern human-drug exclusivity structure.

What formulations are protected by Terramycin?

The commercial formulation is a sterile ophthalmic ointment containing oxytetracycline hydrochloride and polymyxin B sulfate. The formulation’s historical value lies in the combination of:

• A tetracycline-class antibiotic
• Polymyxin B
• An ophthalmic ointment vehicle
• Sterile packaging
• Veterinary labeling for multiple species

The formulation is technically straightforward compared with modern sustained-release implants, biologics, or complex delivery systems. Its main manufacturing barriers are sterility, uniformity, stability, tube filling, and preservation of activity over shelf life.

A competitor could avoid direct brand infringement by using:

• Erythromycin ophthalmic ointment
• Neomycin, polymyxin B, and bacitracin combinations
• Gentamicin ophthalmic products
• Tobramycin ophthalmic products
• Ciprofloxacin ophthalmic products
• Other veterinary-approved antibiotic formulations

These alternatives may differ in spectrum, resistance profile, species labeling, price, and veterinarian familiarity.

How strong is the Terramycin patent estate?

The patent estate is weak as a source of exclusivity. The product’s commercial strength is better described as brand and channel strength.

Factor	Assessment
Patent protection	Weak or absent
Regulatory exclusivity	Expired
Brand recognition	Relatively strong in legacy veterinary use
Clinical differentiation	Moderate to limited
Manufacturing complexity	Moderate because of sterility requirements
Switching costs	Low to moderate
Substitute availability	High
Litigation leverage	Low
Pricing power	Limited, although brand premiums may exist
Supply-chain value	Meaningful if competitors experience shortages

Terramycin’s strongest defense is likely operational. Reliable supply, veterinary distribution, approved labeling, and established purchasing patterns can preserve sales after patent expiry.

Which companies compete with Terramycin?

Competition comes from both branded and generic veterinary ophthalmic products. The most relevant competitive set includes antibiotic ointments and drops rather than only products containing the same two active ingredients.

Competitor category	Examples or product types	Competitive effect
Combination ointments	Neomycin, polymyxin B, and bacitracin products	Direct substitution for superficial bacterial eye infections
Macrolide ointments	Erythromycin ophthalmic ointment	Competes on familiarity and price
Aminoglycoside products	Gentamicin or tobramycin ophthalmic products	Competes where broader or different bacterial coverage is preferred
Fluoroquinolone products	Ciprofloxacin and related drops	Competes in more resistant or serious infections
Compounded products	Veterinary-compounded ophthalmic preparations	Can compete on availability or customization
Distributor brands	Generic veterinary ophthalmic products	Can pressure price and market share

The commercial threat is substitution rather than a single direct generic entrant. Veterinarians can select products according to suspected pathogen, species, severity, dosing convenience, price, and local availability.

What patent litigation affects Terramycin?

No material current US patent litigation involving Terramycin Ophthalmic Ointment has been identified in the public materials cited here.

The litigation profile is favorable to potential entrants because there is no apparent active patent enforcement program tied to the legacy formulation. The main legal risks are more likely to involve:

• Product liability
• Manufacturing-quality claims
• Regulatory noncompliance
• Trademark disputes
• False or misleading promotional claims
• Distribution and supply agreements

No publicly reported settlement agreement appears to control generic or competing entry for this product.

Does Terramycin face biosimilar risk?

No. Biosimilar risk is not relevant because Terramycin is a small-molecule antibiotic ointment, not a biologic. The relevant competition is from generic, equivalent, alternative-brand, and compounded veterinary products.

The product also does not face the complex interchangeability and reference-product issues associated with monoclonal antibodies, recombinant proteins, or other biologics.

What generic launch scenarios exist for Terramycin?

Three entry scenarios are commercially plausible.

Direct equivalent entry

A competitor could seek approval for a veterinary ophthalmic ointment using the same active ingredients or a comparable formulation. This would create the greatest direct price pressure.

Therapeutic substitution

Competitors may gain share without matching the formulation. Erythromycin, aminoglycoside, fluoroquinolone, and triple-antibiotic products can capture demand from veterinarians who prioritize a different spectrum or dosage form.

Supply-driven switching

Temporary shortages, manufacturing interruptions, or distributor delistings could accelerate switching. Veterinary clinics often favor products that are available through established distributors, particularly for routine conditions.

A generic launch would probably reduce price and volume for the branded product, but the impact would depend on contracting, inventory, veterinary loyalty, and whether the entrant secures broad distribution.

What geographic markets are covered?

Terramycin’s strongest commercial relevance is in the United States and other markets where the brand has a long veterinary history. Geographic performance depends on local approval, prescription rules, distributor access, and whether oxytetracycline-polymyxin ophthalmic products are approved under the Terramycin name.

The US product is regulated by the FDA Center for Veterinary Medicine. International products may be subject to separate national or regional registrations and may not have identical labeling, species indications, or prescription status.

Global expansion is unlikely to create a major growth platform because the formulation is mature and substitute products are widely available. International value is more likely to come from maintaining established registrations and distribution relationships.

What is the FDA regulatory status of Terramycin?

The product is an FDA-approved veterinary ophthalmic ointment associated with NADA 8-763. It is labeled for veterinary use and is distributed under the applicable prescription framework.[1][2]

Regulatory risks include:

• Sterility failures
• Manufacturing deviations
• Labeling deficiencies
• Stability problems
• Supply interruption
• Changes in approved manufacturing sites
• Restrictions related to responsible antibiotic use

Because the product contains antibiotics, veterinary antimicrobial stewardship policies can affect prescribing behavior. The effect is likely smaller for topical ophthalmic use than for systemic livestock antibiotics, but regulators and veterinarians remain attentive to unnecessary antimicrobial exposure.

Key Takeaways

• Terramycin with Polymyxin B Sulfate is a mature veterinary ophthalmic ointment containing oxytetracycline hydrochloride and polymyxin B sulfate.
• Zoetis is the principal US company associated with the product.
• Zoetis does not disclose Terramycin revenue, so product-specific financial forecasting is not possible from public filings.
• The product has no identified current patent estate that creates meaningful market exclusivity.
• Orange Book and Paragraph IV analysis do not directly apply because the product is regulated as a veterinary drug.
• Biosimilar risk is not relevant.
• The main competitive threats are generic veterinary ophthalmic products, therapeutic substitutes, compounded products, and supply-driven switching.
• Commercial durability comes from brand recognition, veterinary familiarity, distribution, and sterile manufacturing capability.
• The product is unlikely to be financially material to Zoetis, but it can remain a profitable mature-product asset.

FAQs

Is Terramycin ophthalmic ointment still available for dogs and cats?

Yes. Terramycin Ophthalmic Ointment is marketed for veterinary use and has labeling covering dogs and cats, subject to product availability and applicable prescription requirements.

Is Terramycin the same as oxytetracycline eye ointment?

Terramycin is a brand containing oxytetracycline hydrochloride and polymyxin B sulfate. Oxytetracycline-only products are not necessarily formulation-equivalent.

Can a veterinary pharmacy compound a Terramycin alternative?

A pharmacy may compound veterinary ophthalmic products only within the requirements of applicable federal and state law. A compounded product is not automatically equivalent to the FDA-approved Terramycin product.

Does Terramycin have market exclusivity because Zoetis owns the brand?

Trademark rights can protect the Terramycin name and branding. They do not prevent competitors from selling non-infringing veterinary ophthalmic products with different names.

Could antibiotic-resistance policy reduce Terramycin sales?

Yes. Stewardship policies and veterinarian preference for culture-directed treatment can affect antibiotic use. The impact depends on species, diagnosis, local prescribing practices, and the availability of non-antibiotic or alternative ophthalmic treatments.

References

1. U.S. Food and Drug Administration. (n.d.). Animal Drugs @ FDA: Terramycin ophthalmic ointment, NADA 8-763. Center for Veterinary Medicine. https://animaldrugsatfda.fda.gov/

2. U.S. Food and Drug Administration. (n.d.). Green Book: Approved animal drug products. Center for Veterinary Medicine. https://www.fda.gov/animal-veterinary/products-animal-food/green-book

3. Zoetis Inc. (2024). 2023 annual report. https://www.zoetis.com/investor-relations/financial-information/annual-reports

4. Zoetis Inc. (2025). 2024 annual report. https://www.zoetis.com/investor-relations/financial-information/annual-reports