List of Excipients in Branded Drug SUMYCIN

Generic Drugs Containing SUMYCIN

Company	Ingredient	NDC	Excipient
Par Pharmaceutical Inc	tetracycline hydrochloride	49884-732	ANHYDROUS LACTOSE
Par Pharmaceutical Inc	tetracycline hydrochloride	49884-732	CELLULOSE, MICROCRYSTALLINE
Par Pharmaceutical Inc	tetracycline hydrochloride	49884-732	D&C RED NO. 30
Par Pharmaceutical Inc	tetracycline hydrochloride	49884-732	HYPROMELLOSE
Par Pharmaceutical Inc	tetracycline hydrochloride	49884-732	MAGNESIUM STEARATE
Par Pharmaceutical Inc	tetracycline hydrochloride	49884-732	POVIDONE
Par Pharmaceutical Inc	tetracycline hydrochloride	49884-732	STARCH, PREGELATINIZED CORN

What are the Most Frequently-Used Excipients in SUMYCIN?

# Of NDCs	Excipient
1	ANHYDROUS LACTOSE
1	CELLULOSE, MICROCRYSTALLINE
1	D&C RED NO. 30
1	HYPROMELLOSE
1	MAGNESIUM STEARATE
1	POVIDONE
1	STARCH, PREGELATINIZED CORN

Sumycin Excipient Strategy and Commercial Opportunities for Tetracycline Hydrochloride

Last updated: August 22, 2026

Sumycin is a historical Pfizer brand for tetracycline hydrochloride, an oral broad-spectrum tetracycline antibiotic. Its original commercial value has been displaced by generic tetracycline hydrochloride and newer tetracyclines, including doxycycline and minocycline. The commercial opportunity is therefore not a conventional branded-product relaunch. It is an excipient-led generic, specialty-pharmacy, shortage-resilient, or reformulated oral antibiotic strategy.

The strongest opportunities are improved moisture protection, mineral- and food-interaction labeling, pediatric taste masking, easier swallowing, and dosage-form differentiation. No meaningful current patent or regulatory exclusivity appears to protect the historical Sumycin brand. Any new product would require its own regulatory strategy and could not rely on the legacy brand’s market position.

What is Sumycin and which active ingredient does it contain?

Sumycin contains tetracycline hydrochloride, commonly supplied historically as 250 mg and 500 mg oral capsules or tablets. Tetracycline hydrochloride is a tetracycline-class antibacterial agent used for susceptible bacterial infections, including respiratory, urinary, skin, and selected sexually transmitted infections.

Attribute	Sumycin
Active ingredient	Tetracycline hydrochloride
Therapeutic class	Tetracycline antibiotic
Historical sponsor	Pfizer
Historical dosage forms	Oral capsules and tablets
Common strengths	250 mg and 500 mg
Primary route	Oral
Current brand position	Historical/discontinued brand
Generic pathway	Abbreviated New Drug Application, or ANDA, where an approved reference product and current regulatory pathway are available
Biologic status	Not applicable
Biosimilar exposure	None
Main formulation constraints	Moisture sensitivity, metal-ion chelation, food interactions, light and storage control

Tetracycline should not be treated as interchangeable from a formulation or clinical-positioning perspective with doxycycline or minocycline. Those products have different pharmacokinetic profiles, dosing schedules, tolerability characteristics, and commercial markets.

What excipients were used in historical Sumycin formulations?

Public labeling for historical tetracycline hydrochloride products identifies conventional solid-oral excipients, but the exact inactive-ingredient profile depends on the manufacturer, strength, dosage form, market, and manufacturing period. Historical Sumycin labeling should not be used as the sole specification for a new product.

Typical excipient classes associated with tetracycline hydrochloride capsules and tablets include:

Excipient class	Typical function	Relevance to tetracycline hydrochloride
Lactose or other diluent	Provides tablet or capsule fill weight	Important for patients with lactose intolerance and for powder-flow control
Starch or pregelatinized starch	Filler, binder, disintegrant	Supports capsule fill and tablet breakup
Magnesium stearate	Lubricant	Excess levels can slow dissolution and affect blend uniformity
Sodium lauryl sulfate or wetting agent	Improves powder wetting	Can support dissolution but may affect tolerability or processing
Gelatin	Capsule shell	Creates animal-origin, allergen, and supply-chain considerations
Titanium dioxide and colorants	Capsule or tablet identification	Relevant to market-specific excipient restrictions
Film-coating polymers	Protection and swallowability	Can improve handling, taste, and moisture protection

The commercial issue is not simply matching the historical inactive ingredients. The development target should be a robust formulation that meets dissolution, content uniformity, stability, impurity, and bioequivalence requirements while reducing avoidable excipient liabilities.

What excipient strategy is best for a new Sumycin-equivalent product?

The most defensible strategy is a conventional, low-risk immediate-release solid dosage form with a controlled moisture profile and limited excipient complexity.

Moisture-control strategy

Tetracycline hydrochloride products require careful control of moisture, heat, and storage conditions because tetracycline degradation can produce epimeric and anhydro-related impurities. Degraded tetracycline products have historically raised safety concerns, including renal toxicity.

A commercial formulation should consider:

• Low-moisture excipient grades.
• High-barrier blister packaging or tightly controlled bottles.
• Desiccant inclusion where justified by stability data.
• Moisture-resistant capsule shells or film coatings.
• Reduced exposure to elevated temperature during granulation and drying.
• Stability testing under ICH long-term and accelerated conditions.
• Tight impurity monitoring for degradation products.

A direct-compression formulation may reduce water exposure compared with aqueous wet granulation. The choice depends on powder flow, blend uniformity, tablet tensile strength, dissolution, and scale-up performance.

Chelation and interaction strategy

Tetracycline binds divalent and trivalent cations, including calcium, magnesium, aluminum, iron, and zinc. This can reduce gastrointestinal absorption. Excipients containing relevant mineral ions should be avoided unless there is a specific technical justification and the effect is characterized.

The formulation should generally avoid:

• Calcium phosphate systems that create avoidable calcium exposure.
• Magnesium-containing excipients beyond the minimum needed for processing.
• Mineral-containing flavor systems.
• Iron-containing colorants or nutritional components.
• Antacid-like excipient combinations.

The product label should clearly instruct patients to separate tetracycline from dairy products, antacids, iron preparations, zinc products, and mineral supplements. A formulation that minimizes internal metal-ion exposure will not eliminate patient-level interaction risk.

Disintegration and dissolution strategy

Tetracycline hydrochloride is highly soluble relative to some other tetracycline salts, but dissolution performance remains sensitive to compression force, lubricant concentration, particle size, and wetting behavior.

A practical excipient platform may use:

• Microcrystalline cellulose or an equivalent filler for compactibility.
• Crospovidone, croscarmellose sodium, or sodium starch glycolate as a superdisintegrant.
• A low concentration of magnesium stearate.
• A wetting aid only when dissolution testing supports its use.
• A protective film coat for moisture, odor, and swallowability.

The development target should be rapid and reproducible dissolution across relevant pH conditions, rather than simply matching a legacy excipient list.

What formulations are protected by Sumycin patents?

No commercially significant, unexpired Sumycin formulation patent is known to create a current barrier around the historical product. Tetracycline hydrochloride was discovered and commercialized many decades ago. Core composition, oral capsule, tablet, and antibiotic-use concepts are outside the normal life of small-molecule patent protection.

A new applicant could still obtain patents on a genuinely novel formulation, such as:

• A moisture-stabilized tetracycline hydrochloride composition.
• A multiparticulate or pellet system.
• A taste-masked pediatric granule.
• A modified-release dosage form.
• A specific capsule-shell or packaging combination that materially improves stability.
• A fixed-dose combination with a non-chelating co-ingredient.
• A manufacturing process that produces a defined impurity profile.
• A formulation with demonstrated food-effect or interaction advantages.

Those patents would protect the new formulation, not the historical Sumycin molecule itself. Patentability would require novelty, non-obviousness, written-description support, and credible performance data.

When did Sumycin lose exclusivity?

Sumycin’s original small-molecule exclusivity expired decades ago. The relevant commercial protection is therefore generic competition, not brand exclusivity.

Protection type	Sumycin position
Active-ingredient patent	Historical protection expired
Core oral dosage-form patent	Historical protection expired
New chemical entity exclusivity	Expired
Pediatric exclusivity	No current relevance
Orphan exclusivity	Not applicable
Biologic exclusivity	Not applicable
Current brand exclusivity	No meaningful current protection
Current formulation exclusivity	No known broad legacy barrier

Exact patent expiration dates for the original tetracycline patents are not commercially material because those rights are long expired and do not protect a present-day Sumycin-equivalent product.

What is the FDA regulatory status of Sumycin?

The FDA regulatory position should be separated into the historical brand and current tetracycline hydrochloride products.

Historical Sumycin products are generally treated as discontinued or no longer actively marketed. The commercial pathway for a new product would depend on the availability and regulatory status of an appropriate reference listed drug. An applicant may pursue an ANDA for a therapeutically equivalent product if FDA identifies an acceptable reference product and the proposed dosage form, strength, route, labeling, and performance support ANDA approval.

Key regulatory requirements include:

• Pharmaceutical equivalence to the reference product.
• Bioequivalence.
• Validated analytical methods.
• Stability data.
• Manufacturing-process controls.
• Dissolution and impurity specifications.
• Labeling consistent with FDA-approved tetracycline hydrochloride products.
• Drug Master File support for critical excipients or packaging, where applicable.

A reformulated pediatric liquid, modified-release product, or novel delivery system could fall outside a straightforward ANDA strategy and require a 505(b)(2) application or another FDA pathway. The pathway depends on the proposed claims and the extent of reliance on FDA findings for an existing product.

What is the Orange Book status of Sumycin?

The Orange Book is relevant for identifying reference-listed products, therapeutic-equivalence ratings, patents, and exclusivity. A historical discontinued brand should not be assumed to retain active Orange Book patent listings.

For commercial diligence, the applicant should distinguish among:

1. The historical Sumycin brand.
2. Current approved tetracycline hydrochloride capsules or tablets.
3. Any FDA-designated reference listed drug.
4. Products that remain approved but are not actively marketed.
5. Products with current therapeutic-equivalence codes.

The principal commercial risk is regulatory availability of the reference product, not a legacy Sumycin patent. An ANDA applicant should confirm the current Orange Book entry, dosage-form status, discontinuation designation, and any listed patents before selecting the filing route. [1]

Are there Paragraph IV challenges involving Sumycin?

Paragraph IV litigation is unlikely to be a material issue for the historical Sumycin product because its core patents expired long ago. A new generic applicant would normally face little or no Paragraph IV risk from the original Sumycin brand.

Paragraph IV risk could arise if the target product relies on:

• A current reference product with listed formulation patents.
• A branded reformulation.
• A new modified-release tetracycline product.
• A patented pediatric delivery system.
• A current method-of-use patent covering a labeled indication.

For a conventional immediate-release tetracycline hydrochloride capsule, the primary legal exposure is more likely to involve regulatory eligibility, product-specific patents, trade dress, trademarks, and manufacturing know-how than the original Sumycin patent estate.

How strong is the Sumycin patent estate?

The legacy Sumycin patent estate is weak as a current commercial barrier. The compound is old, the core dosage forms are conventional, and generic tetracycline products have been marketed for many years.

Patent-estate factor	Assessment
Core molecule	No meaningful current exclusivity
Historical oral formulation	No meaningful current exclusivity
Modern excipient combinations	Potentially patentable if technically differentiated
Manufacturing process	Potential opportunity if impurity or yield benefits are demonstrated
Packaging and moisture protection	Possible narrow patent scope
Method of use	Potentially relevant only for new, specific indications
Freedom to operate	Generally favorable for conventional products, subject to current searches
Litigation intensity	Expected to be low for an ordinary generic capsule

A new formulation patent would be stronger if it linked the excipient choice to measurable results, such as improved shelf life, lower degradation, faster dissolution, reduced food effect, or improved pediatric adherence.

What commercial opportunities exist for Sumycin excipient innovation?

Pediatric taste-masked granules

Tetracycline use in children is limited by age-related safety concerns, tooth discoloration, and bone effects. A pediatric product would therefore require a clinically defensible target population and careful labeling. Taste-masked granules or dispersible sachets could have commercial value for selected indications, but the addressable market would be narrower than the adult generic market.

Potential excipient technologies include:

• Polymer-based taste masking.
• Ion-exchange resin complexes.
• Coated multiparticulates.
• Low-moisture dry suspensions.
• Unit-dose sachets.

The formulation must avoid slowing release or reducing bioavailability.

Stable oral suspension or dry syrup

A dry suspension could improve use for patients who cannot swallow capsules. The technical challenge is tetracycline stability after reconstitution. A commercially credible product would need a defined in-use period, clear storage instructions, controlled sedimentation, acceptable redispersibility, and acceptable taste.

A dry powder for reconstitution is generally more attractive than a ready-to-use aqueous suspension if aqueous stability is poor. Packaging and dosing-device design would be important parts of the product rather than secondary features.

Easy-to-swallow capsules

A smaller, high-load capsule or multiparticulate capsule could address swallowing difficulty while retaining a conventional immediate-release profile. Commercial differentiation could come from:

• Reduced capsule size.
• Improved capsule lubricity.
• Odor reduction.
• Moisture-barrier packaging.
• Lower risk of capsule brittleness.
• Unit-dose blister packaging for adherence.

Tablet or capsule products for shortage resilience

Tetracycline hydrochloride is an older antibiotic with a smaller supplier base than major first-line antibiotics. A reliable product with dual-source active pharmaceutical ingredient, qualified excipients, and robust packaging could appeal to wholesalers, hospitals, correctional-health systems, and public-sector buyers.

The opportunity is procurement reliability rather than premium pricing. Buyers will prioritize supply continuity, quality history, lead time, and competitive cost.

Specialty pharmacy and adherence packaging

Calendar blister packs, unit-dose cards, and interaction-focused labeling could support outpatient adherence. These products would not create substantial patent value alone, but they could improve contracting and pharmacy adoption.

How does Sumycin compare with doxycycline and minocycline?

Tetracycline hydrochloride competes primarily on price and established generic availability. Doxycycline has broader contemporary use and often better dosing convenience. Minocycline occupies selected dermatology and infectious-disease niches.

Factor	Tetracycline hydrochloride	Doxycycline	Minocycline
Product age	Very old	Older generic product	Older generic product
Dosing convenience	Less favorable	Generally more favorable	Generally more favorable
Mineral interaction concern	High	Present, but product-specific	Present, but product-specific
Pediatric positioning	Restricted in young children	Age and indication dependent	More limited in some populations
Premium formulation opportunity	Moderate	Higher in specialty delivery systems	Moderate
Generic price pressure	High	High	High
Excipient differentiation	Stability, taste masking, packaging	Modified release and GI/tolerability strategies	Modified release and tolerability strategies

A Sumycin-equivalent product is unlikely to win through molecule-level differentiation. It must compete through reliable supply, lower manufacturing cost, convenient packaging, or a meaningful dosage-form improvement.

What manufacturing and intellectual-property barriers exist?

Manufacturing barriers are more important than legacy patent barriers. Key issues include:

• Control of tetracycline degradation products.
• Consistent API particle size and polymorphic or solid-state characteristics.
• Blend uniformity at relatively low tablet or capsule fill weights.
• Lubricant management.
• Moisture exposure during processing.
• Capsule-shell compatibility.
• Stability under distribution conditions.
• Packaging qualification.
• Cleaning validation for a potent, colored, or cross-contaminating antibiotic powder.
• API supplier qualification and dual sourcing.

A process patent may be commercially useful if it reduces degradation, improves yield, or produces a more stable solid form. Trade secrets around drying, milling, blending, and packaging may provide stronger practical protection than a broad formulation patent.

Which companies are challenging the Sumycin market?

The relevant competitors are manufacturers of generic tetracycline hydrochloride rather than companies challenging Sumycin through branded litigation. Competition may include generic manufacturers, contract development and manufacturing organizations, hospital suppliers, and specialty pharmaceutical companies.

The market structure favors:

• Low-cost capsule manufacturers.
• Suppliers with established ANDA portfolios.
• Companies with reliable tetracycline API access.
• Manufacturers able to support multiple strengths.
• Firms with strong government and institutional procurement channels.
• Developers of pediatric or adherence-oriented formulations.

No biosimilar competition exists because tetracycline hydrochloride is a synthetic small molecule, not a biologic.

What generic launch scenarios exist for a Sumycin-equivalent product?

Conventional generic capsule

This is the lowest-risk technical option and the most price-competitive. The formulation should use a simple excipient system, high-barrier packaging, and standard immediate-release performance.

Differentiated solid oral product

A smaller capsule, tablet, or multiparticulate product could obtain modest commercial differentiation through swallowability, reduced odor, packaging, or stability.

Pediatric dry suspension

This offers greater product differentiation but carries higher formulation, clinical, labeling, taste, stability, and market-size risk.

Modified-release or interaction-reduced product

This could support stronger patent protection, but it would require meaningful pharmacokinetic and clinical justification. The product would no longer be a simple Sumycin substitute.

Institutional supply product

A manufacturer could focus on hospitals, public-health programs, and wholesalers with supply assurance, dual sourcing, and unit-dose packaging. Margin would remain limited, but predictable procurement could support volume.

What revenue exposure does Sumycin have today?

The historical Sumycin brand has little direct revenue relevance unless a company controls an active relaunch, authorized-generic arrangement, or trademark-supported niche product. The economic value sits in the tetracycline hydrochloride category and in any differentiated formulation.

Revenue potential depends on:

• Current prescription volume for tetracycline hydrochloride.
• Generic reimbursement rates.
• Competition by doxycycline and minocycline.
• API cost and supply stability.
• Institutional demand.
• FDA approval pathway.
• Whether the product can command a premium for pediatric, stability, or packaging advantages.

A conventional capsule is likely to be a volume and cost business. A novel formulation could produce higher margins, but only if it solves a documented clinical or operational problem and secures regulatory and patent protection.

Key Takeaways

• Sumycin is a historical tetracycline hydrochloride brand with no meaningful current legacy exclusivity.
• The strongest opportunity is a generic or reformulated tetracycline hydrochloride product, not a conventional brand relaunch.
• Moisture control, impurity management, and high-barrier packaging are central formulation priorities.
• Excipients containing calcium, magnesium, aluminum, iron, or zinc should be avoided or tightly justified because of tetracycline chelation.
• Pediatric taste-masked granules and dry suspensions offer the clearest product differentiation but carry higher regulatory and technical risk.
• A conventional immediate-release capsule has low patent risk and high price pressure.
• New patents would need to cover a measurable technical improvement, such as improved stability, dissolution, taste, or delivery.
• Paragraph IV litigation and biosimilar risk are not material for the historical Sumycin product.
• Manufacturing reliability, API sourcing, packaging, and stability control are more important barriers than the expired Sumycin patent estate.
• The most realistic commercial models are low-cost generic supply, institutional procurement, shortage-resilient manufacturing, and narrowly differentiated oral formulations.

FAQs

Can tetracycline hydrochloride be formulated without lactose?

Yes. Lactose-free formulations can use microcrystalline cellulose, starch derivatives, mannitol, or other compatible fillers. The replacement must preserve powder flow, capsule fill uniformity, dissolution, and stability.

Is a liquid Sumycin formulation commercially attractive?

It can be attractive for patients who cannot swallow solid dosage forms, but aqueous stability and taste are significant barriers. A dry powder for reconstitution is generally more practical than a ready-to-use liquid if tetracycline degrades rapidly in water.

Can a new tetracycline formulation receive patent protection?

Yes, if the formulation has a novel and non-obvious technical feature supported by data. A simple substitution of one conventional filler for another is unlikely to provide strong patent protection.

Does tetracycline hydrochloride require special packaging?

High-barrier packaging is commercially advisable because moisture, heat, and light can affect stability. Blisters, desiccated bottles, and controlled distribution conditions should be evaluated during development.

Is Sumycin interchangeable with doxycycline?

No. Tetracycline hydrochloride and doxycycline are different active ingredients with different dosing, pharmacokinetic, tolerability, and labeling profiles. Therapeutic substitution requires clinical and regulatory consideration.

References

1. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, 44th edition. FDA.

2. U.S. Food and Drug Administration. (2023). Inactive ingredient database. FDA.

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

4. U.S. Food and Drug Administration. (2024). Tetracycline hydrochloride prescribing information. FDA-approved product labeling.

5. International Council for Harmonisation. (2003). Q1A(R2): Stability testing of new drug substances and products. ICH.

6. U.S. Pharmacopeia. (2024). United States Pharmacopeia and National Formulary. United States Pharmacopeial Convention.