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PROMAZINE HYDROCHLORIDE Drug Patent Profile
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When do Promazine Hydrochloride patents expire, and what generic alternatives are available?
Promazine Hydrochloride is a drug marketed by Watson Labs and is included in two NDAs.
The generic ingredient in PROMAZINE HYDROCHLORIDE is promazine hydrochloride. There are thirty-seven drug master file entries for this compound. Additional details are available on the promazine hydrochloride profile page.
US Patents and Regulatory Information for PROMAZINE HYDROCHLORIDE
| Applicant | Tradename | Generic Name | Dosage | NDA | Approval Date | TE | Type | RLD | RS | Patent No. | Patent Expiration | Product | Substance | Delist Req. | Exclusivity Expiration |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Watson Labs | PROMAZINE HYDROCHLORIDE | promazine hydrochloride | INJECTABLE;INJECTION | 084510-001 | Approved Prior to Jan 1, 1982 | DISCN | No | No | ⤷ Start Trial | ⤷ Start Trial | ⤷ Start Trial | ||||
| Watson Labs | PROMAZINE HYDROCHLORIDE | promazine hydrochloride | INJECTABLE;INJECTION | 084517-001 | Approved Prior to Jan 1, 1982 | 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 |
Promazine Hydrochloride Investment Scenario and Patent/Regulatory Fundamentals (US)
Promazine hydrochloride is a first-generation phenothiazine antipsychotic with long-standing generic availability in the US. From an investment and licensing standpoint, the key fundamentals are (1) the lack of near-term exclusivity drivers typical of modern small-molecule assets, (2) likely thin remaining IP protection tied to legacy compositions and older methods, and (3) low likelihood of a pathway to meaningful incremental market protection unless a novel formulation, dosing regimen, or new indication has active, enforceable US rights.
Bottom line: treat promazine hydrochloride as a mature, low-growth, mostly price-competitive product where investor value usually comes from manufacturing scale, supply chain reliability, and any narrow, defensible IP around specific dosage forms or brand-side lifecycle protection.
Is promazine hydrochloride still patent-protected in the US? What patents protect promazine hydrochloride today?
Featured snippet answer: For a legacy, off-patent active ingredient like promazine hydrochloride, current US protection typically does not cover the active ingredient itself in a way that blocks generic entry. Any remaining enforceable rights are usually limited to specific formulations, solid-state forms, process improvements, or method-of-use claims that are narrow and fact-dependent.
What the patent estate normally looks like for older phenothiazines
For drugs in the phenothiazine class (including promazine), historical filings often created:
- composition-of-matter coverage on the active ingredient or salts
- formulation patents (tablets, syrups, injectables, particle size, granulation)
- manufacturing/process patents (specific synthesis or purification steps)
- method-of-use claims tied to specific clinical protocols
In mature markets, the commercial gating item is usually not the existence of patents but whether those patents are still in force and listed in the FDA Orange Book against a particular dosage form/strength.
Practical investment implication
- If the active ingredient and core oral dosage forms are generic, investment returns depend on cost-to-serve and regulatory/CMC execution, not exclusivity.
- If any remaining patents are narrow (eg, only for a specific injectable suspension or a particular release profile), the deal logic becomes product-specific rather than molecule-wide.
What is the Orange Book status of promazine hydrochloride (FDA listings, exclusivity, and patents)?
Featured snippet answer: Orange Book status is the primary screen for whether any promazine hydrochloride product in the US retains listed patents or exclusivity. For most first-generation antipsychotics with decades of market history, typical Orange Book outcomes are no unexpired patents for generic-blocking entry or only limited formulation listings.
How to interpret Orange Book listings in a promazine hydrochloride investment model
In a licensing or manufacturing acquisition model, the key variables are:
- whether any unexpired patents are listed for the specific dosage form
- whether those patents are composition/formulation or method-of-use
- whether there is evidence of Paragraph IV certifications or recent litigation
- whether the listed patents track a specific label (strength, route, dosing form)
Without a live Orange Book listing and patent code set for each strength/route, promazine hydrochloride should be treated as exclusivity-light for US market entry.
When does promazine hydrochloride lose exclusivity? Expiration timelines and generic entry risks
Featured snippet answer: For older small-molecule generics where the active ingredient has long passed the initial regulatory protection window, the “loss of exclusivity” typically occurs years earlier. Residual protection, if any, is tied to specific dosage forms and listed patents, not to molecule-level exclusivity.
Investor lens: what actually drives generic launch timing
For legacy drugs, the generic launch timeline is dominated by:
- expiration of the last listed blocking patent for a given strength/route
- whether the innovator or branded producer maintains an FDA-protected New Chemical Entity or 505(b)(2) exclusivity record (less likely for promazine)
- whether there are enforceable patent families with staggered expiries
- any settlement agreements that create delayed entry
Generic entry risk profile
- High probability of generic supply for an off-patent, widely marketed active ingredient
- Low probability of a coordinated exclusivity wall unless a specific formulation is protected
Has promazine hydrochloride faced Paragraph IV challenges? What patent litigation affects generic entry?
Featured snippet answer: For mature generics, Paragraph IV litigation is typically absent or sporadic unless a particular dosage form is tied to a still-active patent listed in the Orange Book.
Investment implication of litigation absence
If there is no active protracted litigation:
- generic entry tends to occur without long delays
- pricing pressure stays persistent
- “special situation” licensing usually does not exist around settlement-linked exclusivity
What formulations are protected by promazine hydrochloride patents? Tablets, injectables, syrups
Featured snippet answer: If any remaining US IP exists, it is most likely to be formulation- or process-focused rather than covering the base salt itself.
Dosage-form segmentation that matters for value
Even for off-patent APIs, dosage forms can create localized differentiation:
- oral tablets vs liquid formulations
- injectable forms (sterility assurance, stability, and presentation)
- stability enhancements (storage, precipitation control)
- bioavailability modifiers (less likely for older drugs; still possible for specific reformulations)
How this changes the investment case
- Manufacturing investments become the economic center of gravity.
- Any “IP-backed” premium likely attaches to a specific SKU (route + strength) rather than the whole product line.
How does promazine hydrochloride compare with other phenothiazines for investment potential (thioridazine, chlorpromazine, trifluoperazine)?
Featured snippet answer: Other first-generation phenothiazines show the same macro pattern: mature, generic-heavy markets with limited ongoing exclusivity. Investment upside usually comes from supply-chain and production economics, not from new IP-driven growth.
Relative attractiveness drivers across phenothiazines
- presence of still-listed Orange Book patents
- presence of injectable supply constraints (sterility and capacity)
- existence of hospital formulary differentiation (rare for widely generic drugs)
- any new indication with enforceable method-of-use rights (rare in legacy phenothiazines)
Investment implication
Treat promazine hydrochloride like a commodity-like segment unless a specific dosage form has still-valid, enforceable protection or limited manufacturing capacity.
What manufacturing and IP barriers exist for promazine hydrochloride generics? CMC constraints
Featured snippet answer: For an established generic active ingredient, the highest barriers are usually CMC execution and regulatory quality, not molecule-level IP.
CMC and supply-chain levers that affect returns
- impurity control and analytical method transfer
- stability and shelf-life performance across temperatures
- sterile manufacturing controls for injectables
- packaging configuration (especially for liquids)
- continuity of API sourcing and batch consistency
Investment implication
A credible entrant or acquirer wins by:
- lowest landed cost with consistent quality
- reliable regulatory dossiers
- fast re-sourcing of API to reduce stock-out risk
Which companies are likely competing in promazine hydrochloride and how does that shape pricing power?
Featured snippet answer: Competition for legacy antipsychotics typically comes from multiple generic manufacturers across the supply chain, compressing margins.
Pricing power assessment framework
- number of ANDA products per dosage form
- historical price volatility after generic launches
- presence of supply disruptions that temporarily lift pricing
- buyer concentration in wholesale and hospital channels
Investment implication
Expect limited sustainable pricing power. Margin improvement usually requires operational excellence rather than exclusivity.
What FDA pathway would a new promazine hydrochloride product use (ANDA vs 505(b)(2))?
Featured snippet answer: A new version of an already marketed generic active ingredient typically uses ANDA (505(j)). A 505(b)(2) path is generally used when the applicant relies on published literature or a reference listed drug but adds a change that has a regulatory basis for bridging.
Investor lens
- ANDA implies fast timeline and limited exclusivity, so economics must support short-cycle execution.
- 505(b)(2) implies more clinical/bridging and cost, so it only makes sense if it can defend label expansion or differentiated formulation with defensible rights.
Revenue exposure: what portion of promazine hydrochloride is likely exposed to generic price compression?
Featured snippet answer: For promazine hydrochloride, revenue is typically fully exposed to generic competition if the product is off-patent across the relevant US dosage forms.
How to model downside and baseline
- assume pricing tracks the lower-cost generic tier
- assume share is contestable through procurement and contract mechanics
- treat special situations (shortages, recalls, supply disruptions) as episodic
Key takes for investment: Where could promazine hydrochloride still create value?
Featured snippet answer: Value creation is most plausible through defensible manufacturing positioning, narrow formulation differentiation, or opportunistic licensing tied to specific dosage forms or protected methods still within their patent window.
Actionable value nodes
- acquire or build capability for high-reliability sterile or liquid production if that segment is capacity-constrained
- pursue product-specific differentiation where any remaining IP exists for a particular SKU
- target hospital procurement channels that reward supply reliability and supply continuity
- evaluate whether any remaining patents listed for specific dosage forms still block entry and are enforceable
Key Takeaways
- Promazine hydrochloride is a mature, generic-heavy active ingredient; exclusivity-driven upside is typically limited.
- Any enforceable US IP is most likely formulation- or method-specific and therefore SKU-dependent rather than molecule-wide.
- Investment returns are likely driven by CMC reliability, regulatory execution, and supply-chain scale, not by patent exclusivity.
- Generic entry risk is high and pricing power is usually constrained unless a specific dosage form has operational bottlenecks or still-valid listings.
FAQs
1) Is promazine hydrochloride available as a generic in the US?
Yes. Market availability is typical for mature antipsychotics; investment should model competitive pricing and multiple suppliers.
2) Would a new promazine hydrochloride formulation qualify for exclusivity?
Only if it triggers a recognized exclusivity pathway under FDA rules and has supporting regulatory differentiators; otherwise it is likely treated as incremental change without exclusivity.
3) What are the highest-risk parts of a promazine hydrochloride CMC submission?
Impurity control, stability across shelf-life, and for injectables, sterile manufacturing and container closure performance.
4) Does method-of-use patent protection matter for promazine hydrochloride generics?
It can, but method-of-use claims for legacy drugs are often narrow and fact-specific; practical value depends on active, enforceable US rights tied to the current label.
5) How do supply shortages affect promazine hydrochloride pricing and margin?
Shortages can temporarily improve pricing and margins, but they are episodic and should be modeled as events rather than a structural advantage.
References
- FDA. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. U.S. Food and Drug Administration.
- FDA. ANDA regulations and 505(j) pathway overview. U.S. Food and Drug Administration.
- FDA. Drug Innovation and Licensing (Orange Book) and exclusivity information. U.S. Food and Drug Administration.
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