When will the SULFAMETHOXAZOLE AND TRIMETHOPRIM AND PHENAZOPYRIDINE HYDROCHLORIDE patents expire, and when will generic SULFAMETHOXAZOLE AND TRIMETHOPRIM AND PHENAZOPYRIDINE HYDROCHLORIDE be available?

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Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Able	SULFAMETHOXAZOLE AND TRIMETHOPRIM AND PHENAZOPYRIDINE HYDROCHLORIDE	phenazopyridine hydrochloride; sulfamethoxazole; trimethoprim	TABLET;ORAL	021105-001	Jun 26, 2001		DISCN	No	No	⤷ Start Trial	⤷ Start Trial				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Exclusivity Expiration

Last updated: July 19, 2026

Suĺfamethoxazole and Trimethoprim and Phenazopyridine Hydrochloride (UTI Combo) Investment Scenario and Fundamentals Analysis: Pricing, Exclusivity, Patent/Generic Risk, and Commercial Outlook

Executive summary: Sulfamethoxazole and trimethoprim plus phenazopyridine hydrochloride is an established oral therapy used for acute uncomplicated urinary tract symptoms where clinicians pair an antibacterial (SMX-TMP) with symptomatic bladder pain relief (phenazopyridine). From an investment perspective, the product class has high generic depth risk, limited patent-driven pricing power, and low likelihood of near-term disruptive exclusivity expansion. Fundamentals are driven by UTI incidence and treatment share, payer formularies favoring generics, antimicrobial resistance and guideline adherence, and manufacturing continuity rather than differentiation. The key diligence focus is confirming which specific finished-dose combination, NDC, and label claims are in scope because the patent and exclusivity posture varies by formulation strength, brand holder, and route.

How do sulfonamide trimethoprim phenazopyridine combinations generate revenue in the US market?

Core revenue drivers:

Uncomplicated UTI incidence and symptom burden. Phenazopyridine is used for short-term dysuria relief.
Prescriber behavior. In practice, many clinicians default to antibiotic-only regimens for uncomplicated cystitis, then add symptomatic agents selectively based on pain and patient preference.
Payer and pharmacy economics. Generics for SMX-TMP are typically low-cost, and phenazopyridine is widely available. Commercial reimbursement tends to track low WAC-to-NAD economics.
Channel mix. Revenue is dominated by retail prescription volume rather than provider-administered channels.

Business implication: For most investment theses, upside is constrained by generic competition. A viable thesis usually requires one of: (i) proprietary formulation with meaningful payor value, (ii) a specialty channel with differentiated distribution, or (iii) a litigation settlement that delays generic entry for the specific product presentation.

What is the patent estate risk for sulfamethoxazole and trimethoprim with phenazopyridine hydrochloride in the US?

Investment conclusion for IP: The active ingredients (sulfamethoxazole, trimethoprim, phenazopyridine hydrochloride) are long-established. The primary patent risk for any “combination” product is typically concentrated in one of these buckets:

Finished-dose combination patents (specific ratio, dosage strengths, and manufacturing controls).
Formulation and stability patents (compression, coating, solid-state stability, shelf-life extension).
Method-of-use patents (less common for this class in US practice, unless tied to novel dosing regimens or patient selection).
Orange Book-listed patents for a specific NDC and NDA.

Where investor diligence often finds exposure:

If the marketed product is effectively generic already, the practical question becomes not “is there a patent?” but “which specific NDC presentation is still protected, and until when?”
If the brand claims are limited, the patent estate may be thin and vulnerable to Paragraph IV challenges on weak or narrow claims.

Featured snippet answer: For established UTI symptom + antibiotic combinations, the US patent estate is usually narrow and expiration-driven, with generic entry risk present regardless of brand visibility.

When does generic competition typically reduce price for sulfamethoxazole trimethoprim phenazopyridine hydrochloride combinations?

Timing mechanics that matter commercially:

Regulatory exclusivity (if any) ends independently of patents and can enable earlier approvals but not launch until patent barriers clear.
Patent expiration and “carve-outs.” Even when the active ingredients are off-patent, a specific formulation or method-of-use can delay.
Paragraph IV filing: If an ANDA challenger files with a Paragraph IV certification, launch can be permitted after the statutory stay period and upon expiration of relevant patents.

Investment relevance: In this therapeutic space, price compression often follows:

Loss of any remaining exclusivity,
Any final resolution of patent challenges,
Then sustained low pricing driven by competitive generic multi-source supply.

What patents protect fixed-dose sulfamethoxazole and trimethoprim plus phenazopyridine hydrochloride products?

Patent estate mapping approach for diligence (what to look for):

Orange Book patent families tied to the exact NDC for the combined product.
Claim scope: ratio specificity, solid form, manufacturing process, and dosing schedules.
Expiration dates: earliest independent claim expiry (not filing date).
Terminal disclaimers: these can align multiple patents to the same expiration.
Litigation history: whether courts have already narrowed claim construction for similar products.

Commercial implication: The strongest investment cases in mature UTI combinations show a clear, date-certain barrier that prevents immediate ANDA launches for the exact presentation.

What formulations are protected: tablets vs combination dosing vs sustained release?

Formulation sensitivity:

Immediate-release tablets are generally easier to copy and more likely to face thin IP barriers.
Any non-obvious manufacturing or stability-driven restrictions can be material, especially if tied to shelf-life and acceptable dissolution profiles for phenazopyridine.
Coated vs uncoated solids can have distinct patent coverage.

Investor screening metric: Focus on whether any listed formulation patents claim:

A specific manufacturing method,
A specific solid-state form,
A stability shelf-life extension,
Or a particular dissolution/release specification.

How strong is the patent estate for sulfamethoxazole and trimethoprim plus phenazopyridine hydrochloride, and what drives enforceability?

Strength drivers:

Breadth vs narrowness of claims. Narrow claims tied to unique ratios or manufacturing steps are easier for generics to design around.
Written description support and enablement quality.
Litigation posture: prior claim construction and whether courts have dismissed or narrowed core claims.

Common practical outcome in this drug class: Even where patents exist, enforceability often reduces to a narrow subset of the product universe. That narrows the commercial shelf-life advantage unless the brand’s exact NDC remains the only protected presentation.

What Orange Book status applies to sulfamethoxazole and trimethoprim and phenazopyridine hydrochloride combination products?

How investors should interpret Orange Book listings:

Confirm whether patents are listed against an NDA (not only granted patents in the abstract).
Identify:
- “Drug substance” vs “drug product” vs “method-of-use” patents,
- Patent “expiration” vs “estimated expiration,”
- Any listed pediatric exclusivity or orphan exclusivity (unlikely here but must be checked for completeness in the specific NDA record).
Determine the NDA’s current authorization and whether the product is active, discontinued, or replaced by an AB-rated equivalent.

Featured snippet answer: The Orange Book status is typically the decisive map for launch risk because it anchors Paragraph IV certifications to the exact NDC and claims.

What generic entry risks exist for sulfamethoxazole trimethoprim phenazopyridine hydrochloride?

Primary generic entry vectors:

ANDAs referencing the approved combination and seeking approval before patent expiry.
Design-around strategies, such as alternate manufacturing or distinct formulation that avoids a formulation-method claim.
Switching to separate products (antibiotic plus phenazopyridine) if payor economics and label guidance permit; this is often a major competitive substitute even when the combination form is protected.

Investor lens: In mature UTI symptom markets, generic substitutes do not require perfect product equivalence. If separate generics cost less and meet prescriber comfort, the combination’s pricing power erodes.

What patent litigation affects sulfonamide trimethoprim phenazopyridine hydrochloride combos?

Litigation items to diligence for:

Parties and timeline: filing dates, district court outcomes, Federal Circuit appeals.
Claim construction outcomes: whether key claims were limited or invalidated.
Settlement terms: whether there is a stipulated launch date, label carve-outs, or licensing of patents.
Whether a settlement protects the brand-only NDC or also addresses authorized generics.

Business outcome: For combination antibiotics + symptomatic agents, settlements often create predictable launch calendars. Without those barriers, generic launches compress pricing quickly.

Which companies supply or compete in sulfamethoxazole trimethoprim phenazopyridine hydrochloride?

Competitive landscape structure in this category:

Established generic manufacturers with ANDA capacity,
Retail pharmacy-driven demand,
Potential private label or alternative packaging across strengths.

Investment implication: The competitive threat is usually about volume share capture at low price points, not about differentiation. That increases the role of cost structure and supply reliability.

How does this combination compare with antibiotics-only regimens for uncomplicated cystitis?

Relative clinical and commercial positioning:

Antibiotics-only (e.g., SMX-TMP alone in eligible patients) reduce blister symptoms without adding urinary analgesia.
Phenazopyridine is symptom-targeted, typically for short durations.
In payer formularies, symptomatic agents face different coverage rules, and some plans prefer step therapy or restrict NSAID alternatives.

Commercial consequence: The combination competes not only with other combination fixed doses but also with “two-product” prescribing patterns. That lowers the maximum sustainable price any single combined product can sustain.

What regulatory pathway considerations apply: NDA vs ANDA vs 505(b)(2)?

Regulatory mechanics that affect launch:

ANDA approval for generics typically drives fast competition once patents clear.
505(b)(2) can be used for reformulations or bridging using literature/assessments, but for established actives the scope is often limited.
Labeling and dosing must match reference standards for effective substitution.

Investment relevance: A competitor’s choice of pathway signals speed and certainty. ANDA pathways with Paragraph IV certifications are a common near-term launch threat.

What does a plausible near-term launch scenario look like for sulfonamide trimethoprim phenazopyridine hydrochloride combinations?

Scenario framework (useful for model-building):

Base case: gradual erosion as multi-source supply increases; revenue declines with generic substitution.
Adverse case: Paragraph IV triggers earlier generic entry; further declines after any stipulated settlement date.
Upside case: a narrow formulation or method patent blocks the exact NDC launch longer than market expects; brand holds a remaining niche for a period.

Financial modeling implication: Build scenarios around:

NDC-level prescription volume decline,
Gross margin compression from wholesale price drops,
Contracting and rebate dynamics with pharmacy benefit managers (PBMs).

Investment screening checklist: what to verify before underwriting

Exact product identification
- Finished-dose strengths and route (oral).
- NDC-level mapping to the approved reference product.
Orange Book mapping
- Listed patents tied to that NDC.
- Earliest expiration and any listed method-of-use barriers.
Exclusivity flags
- Whether any exclusivity exists beyond patents for the relevant NDA.
Litigation / settlement
- Paragraph IV statuses for ANDAs that reference the specific NDA.
- Stipulated launch dates or label carve-outs.
Substitute economics
- Cost comparison vs antibiotic-only + phenazopyridine separate products.
- Likely prescriber switching behavior under formulary pressure.
Manufacturing and supply
- History of supply constraints can temporarily support price; sustained reliability is required for durability.

Key Takeaways

Commercial reality: Revenue in SMX-TMP + phenazopyridine combination therapy is constrained by the maturity of actives and strong payer preference for low-cost generics.
Main investment risk: NDC-specific patent estate weakness and generic substitution, including “two-product” antibiotic plus phenazopyridine prescribing.
Main diligence lever: Orange Book listing verification at the NDC level, and tracking Paragraph IV filings and any settlement dates tied to the exact protected presentation.
Best underwriting cases: Any clearly date-certain, enforceable barrier that delays ANDA launches for the exact combined product and strengths.
Most likely trajectory: If no strong, NDC-specific barriers remain, pricing and volume will trend downward as additional generics enter.

FAQs

1) What drives pharmacy demand for phenazopyridine-containing UTI regimens?

Dysuria and urinary discomfort symptom control, prescriber habits, and short-course use patterns that align with pain relief needs.

2) Do patients substitute separate sulfamethoxazole-trimethoprim and phenazopyridine for the combination product?

Yes, commonly when the combination is not competitively priced or when formulary preferences support separate generics.

3) Which claims typically survive longest for combination UTI products?

Claims that are specific to the drug product formulation, manufacturing method, or a narrowly defined release/dissolution profile are more likely to delay straightforward copy products.

4) How should investors interpret a Paragraph IV certification for this drug class?

It signals a challenger’s belief that one or more listed Orange Book patents are invalid and/or not infringed, and it can trigger a predictable statutory stay and then launch if patents fall.

5) What is the most important commercial KPI for underwriting this therapy?

NDC-level prescription volume trends and the timing of generic share gains, not average list price alone.

References (APA)

No sources were cited because no verifiable NDA/NDC-specific Orange Book, patent numbers, expiration dates, or litigation records were provided in the prompt.

SULFAMETHOXAZOLE AND TRIMETHOPRIM AND PHENAZOPYRIDINE HYDROCHLORIDE Drug Patent Profile

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