Details for Patent: 9,233,112

Which drugs does patent 9,233,112 protect, and when does it expire?

Patent 9,233,112 protects SUPRAX and is included in one NDA.

This patent has two patent family members in two countries.

Summary for Patent: 9,233,112

Title:	Pharmaceutical compositions of cefixime
Abstract:	A pharmaceutical suspension dosage form comprising greater than 80 mg/ml and not more than 150 mg/ml of Cefixime and pharmaceutically acceptable excipients.
Inventor(s):	Shrenik Annasaheb Kole, Bharat Raghunath Metkar, Makarand Krishnakumar Avachat
Assignee:	Lupin Ltd
Application Number:	US13/156,146
Patent Claim Types: see list of patent claims	Use; Composition; Formulation; Dosage form;

US Patent 9,233,112 (Cefixime oral suspension): Scope, claim strategy, and US patent landscape for bioequivalence-based cefixime powder

Executive summary: US Drug Patent 9,233,112 covers a powder for oral suspension of cefixime designed to yield a reconstituted 100 mg/mL cefixime concentration and to be bioequivalent to a specific marketed comparator (described in the claim as 200 mg/5 mL cefixime trihydrate suspension) under fasted and fed conditions. The independent claim is formulation- and equivalence-driven, with dependent claims enumerating allowable excipient classes (sweeteners, diluents, viscosity agents, dispersing agents, flavors, preservatives). A limited set of therapeutic method claims extends use to selected infectious indications. From a freedom-to-operate perspective, the claim set is narrow in active product attributes (powder-to-suspension cefixime reconstitution) and broad in excipient permissiveness inside the recited lists, making equivalency and formulation design-around the main litigation and generic-risk levers.

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What is US Patent 9,233,112 and what does it claim for cefixime powder for oral suspension?

Claim core (independent claim 1): A powder for oral suspension comprising cefixime that, after reconstitution, provides 100 mg/mL cefixime, with the resulting suspension bioequivalent to 200 mg/5 mL cefixime trihydrate marketed suspension under both fast and fed conditions, plus pharmaceutically acceptable excipients.

Practical reading of scope

• Product form: “powder for oral suspension” is required, not a ready-to-use liquid, not granules for other administration.
• Reconstituted potency: the claim locks the target concentration at 100 mg/mL cefixime upon reconstitution.
• Bioequivalence anchor: bioequivalence is tied to a specific comparator dose form and active salt (cef ixime trihydrate, 200 mg/5 mL).
• Study conditions: the claim explicitly includes fast and fed bioequivalence.

What features make claim 1 formulation-anchored rather than use-anchored?

Claim 1 is directed to the composition and resulting reconstituted pharmacokinetic performance. Unlike patents that hinge on a narrow manufacturing step or unique polymorph/co-crystal identity, this claim’s enforceability turns on:

• measurable bioequivalence outcomes under fed and fast conditions, and
• whether the accused product falls within the required reconstitution concentration and is a powder yielding an oral suspension.

Is the patent limited to cefixime trihydrate or any cefixime form?

The comparator in the bioequivalence requirement is cef ixime trihydrate at 200 mg/5 mL. Claim 1 does not, on its face, require the accused composition to be cefixime trihydrate; it requires cef ixime and the bioequivalence to the comparator. That means the patent landscape risk is driven by whether alternative polymorphs or salts can still meet the claim’s bioequivalence and concentration constraints.

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How broad are the excipient claims in US 9,233,112?

Claims 2 through 7 are dependent and list allowable excipient categories using “selected from the group consisting of … and mixtures thereof.” That structure can function in two ways in claim construction:

1. If the formulation includes at least one listed excipient in each recited category, the claim is satisfied for that dependent category; and
2. If formulations include excipients outside the lists, infringement may turn on whether the “consisting of” language is treated as excluding unlisted members for that category.

What diluents are covered? (Claim 2)

Diluents selected from:

• sucrose, sorbitol, xylitol, dextrose, fructose, maltitol, aspartame, saccharin, saccharin sodium, mixtures thereof.

What sweeteners are covered? (Claim 3)

Sweeteners selected from:

• fructose, glucose, sucrose, mannitol, sorbitol, sodium saccharine, sodium cyclamate, aspartame, mixtures thereof.

What viscosity enhancing agents are covered? (Claim 4)

Viscosity enhancing agents selected from:

• xanthan gum, guar gum, acacia, alginic acid, sodium alginate, propylene glycol alginate, povidone, carbomer, salts of carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, bentonite, polydextrose, carrageenan, sucrose, sorbitol, xylitol, dextrose, fructose, maltitol, gelatin, tragacanth, polyvinyl alcohol, cetearyl alcohol, colloidal silicon dioxide, mixtures thereof.

What dispersing agents are covered? (Claim 5)

Dispersing agents selected from:

• colloidal silicon dioxide and surfactants.

What flavoring agents are covered? (Claim 6)

Flavorings selected from:

• strawberry flavor, banana flavor, cream flavor, mixtures thereof.

What preservatives are covered? (Claim 7)

Preservatives selected from:

• sodium benzoate, benzoic acid, EDTA (ethylenediaminetetraacetic acid), sorbic acid, benzethonium chloride, benzalkonium chloride, bronopol, butyl paraben, methyl paraben, ethylparaben, propyl paraben, thiomerosol, sodium propionate, chlorhexidine, chlorobutanol, chlorocresol, cresol, imidurea, phenol, phenylmercuric salts, potassium sorbate, propylene glycol, mixtures thereof.

Design-around implication: excipient selection vs. bioequivalence

Because claim 1 is independent, an alleged infringer cannot avoid claim 1 infringement simply by changing excipients if the resulting powder-suspension still meets the required bioequivalence and reconstitution concentration. Dependent claims can broaden or narrow practical enforcement:

• If a challenger’s product uses excipients within the lists, it is easier for the patentee to argue dependent claim coverage.
• If a product uses excipients outside the lists, a patentee may still assert claim 1 but not necessarily dependent claims 2-7.

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Which therapeutic methods are covered by US 9,233,112?

Claims 8 and 9 add method-of-use coverage, tying administration of the claimed suspension to infectious indications.

Claim 8 method indications

Administration of the claim 1 suspension to treat:

• acute bacterial otitis media,
• pharyngitis,
• tonsillitis,
• acute bronchitis,
• chronic bronchitis.

Claim 9 method indications

Administration to treat:

• uncomplicated urinary tract infections,
• gonorrhea,
• or both.

How narrow are the method claims?

These method claims cover specific indication sets. They do not, based on the provided claim text, cover broader “bacterial infections” or other cefixime uses. For infringement, the patentee still needs proof of administering the claimed suspension for one of the listed indications.

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What is the legal and technical strength of an equivalence-based formulation claim?

The claim’s novelty lever is bioequivalence under fast and fed conditions versus comparator cef ixime trihydrate suspension.

Strength drivers

• Bioequivalence is measurable in PK studies. If an accused generic’s BE results match, the evidentiary pathway can be direct.
• The claim fixes the reconstituted concentration at 100 mg/mL, limiting accidental overlap.

Weakness drivers

• Bioequivalence often depends on study design and variability. Defense efforts can focus on:
  • whether the accused product truly produces the same concentration upon reconstitution,
  • whether BE comparisons are performed properly under both fed and fast conditions,
  • whether the accused product differs in key formulation attributes affecting absorption.

Key point for litigation: The claim is not solely about “cef ixime oral suspension.” It is about a powder that produces a specific concentration and demonstrates BE to a comparator under specific conditions.

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Where does US 9,233,112 likely sit in the cefixime US patent landscape?

Claim-type positioning

US 9,233,112 is a formulation + BE patent. That typically clusters in a mid-to-late lifecycle around:

• reformulation of older antibiotics,
• generic entry timing for oral pediatric formulations, and
• Orange Book-listed reference product reformulations and BE-based generics.

Patent coverage pattern in cefixime products (industry pattern)

Cefixime oral suspension products often attract multiple patent categories:

1. Active ingredient composition (less common for new patents unless improved polymorph/salt or new stability form),
2. Formulation and excipients (thickening, sweetening, dispersing, preservatives),
3. Manufacturing or stability (process steps, shelf-life stabilization, moisture protection),
4. PK/bioequivalence bridging (BE-specific claims like this one),
5. Method-of-use (indications with listed pathogens),
6. Device/dosing (rare for powder suspensions, but sometimes dosing cup or reconstitution instructions are separately protected).

US 9,233,112 is concentrated in (2) and (4) with a limited (5).

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Which companies are likely impacted by US 9,233,112 and how do generic entry risks map?

Generic risk mapping (high-level, based on claim scope only):

• Any US-marketed cef ixime oral suspension powder that reconstitutes to 100 mg/mL and is BE to the 200 mg/5 mL marketed trihydrate suspension under fed and fast conditions presents infringement risk.
• If the product targets the same pediatric dosing experience, the odds of matching the PK profile and excipient framework rise, especially where typical oral suspension excipient packages overlap with the claim’s lists.

Settlement leverage pattern For patents like this, litigation leverage often centers on:

• accused product BE study results,
• whether “bioequivalent to comparator under fed and fast” is provable and repeatable, and
• whether design-around preserves clinical BE targets.

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When does US 9,233,112 lose exclusivity, and what launch windows matter?

This section cannot be completed from the provided information because the patent’s:

• filing date,
• priority date,
• patent term adjustment (PTA),
• terminal disclaimer status,
• and any FDA regulatory exclusivity interactions, are not provided.

Therefore, no enforceable expiration timeline is stated here.

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What is the Orange Book status of US 9,233,112 for cefixime oral suspension?

This cannot be determined from the provided information alone because Orange Book listings require:

• the reference product NDA/BLA,
• listed patents for that NDA/BLA,
• and the specific Orange Book expiration/notification data.

Therefore, Orange Book status is not provided.

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How would a Paragraph IV challenge likely attack US 9,233,112?

Given the claim construction implied by the text, a Paragraph IV framework would commonly focus on:

Noninfringement theories

• The accused powder does not yield the claimed 100 mg/mL upon reconstitution.
• The accused suspension is not “bioequivalent to 200 mg/5 mL cefixime trihydrate suspension” under fast and fed conditions.
• The accused formulation uses excipients outside the enumerated lists such that dependent claims 2-7 are not met (while claim 1 is still the main battleground).

Invalidity theories likely to be asserted

• Anticipation or obviousness based on earlier cefixime oral suspension formulations demonstrating BE to marketed comparators.
• Challenges to whether “bioequivalent under fast and fed conditions” is supported and definite in a way that differentiates over prior art.

Claim vulnerability note: BE-driven claims are sometimes attacked as functional at the result level, but enforceability depends on how the specification ties the formulation to the BE outcomes. That content is not provided here.

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How does US 9,233,112 compare with other cefixime patents by claim type?

Compared with excipient-only patents

• US 9,233,112 is stronger than pure excipient listing because it includes an outcome requirement (BE under fast/fed).
• Excipient-only patents can be easier to avoid by selecting unlisted excipients; BE-based claims are harder to avoid if PK profiles are preserved.

Compared with manufacturing-process patents

• Process patents require proof of the manufacturing method; US 9,233,112 is product-attribute based and can be asserted based on the marketed finished product performance.

Compared with polymorph/co-crystal patents

• Salt/form patents are narrower in chemical identity.
• This patent is broader in chemical identity (cef ixime is the active; comparator is trihydrate) but narrow in BE and concentration target.

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What formulations are likely to fall inside or outside US 9,233,112?

Likely inside

• Powder reconstituting to 100 mg/mL cefixime.
• BE results matching a comparator equivalent to 200 mg/5 mL marketed cef ixime trihydrate suspension in fed and fast states.
• Excipient sets using listed diluents/sweeteners/viscosity/dispersants/flavors/preservatives, especially where those are typical for pediatric oral suspensions.

Likely outside

• Products reconstituting to a different concentration than 100 mg/mL.
• Products that do not meet BE under either fed or fast conditions relative to the specified comparator.
• Formulations that intentionally deviate from BE goals by changing absorption characteristics, while potentially still meeting FDA approval via alternative evidence (not covered by this claim text).

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Key takeaways

• US 9,233,112 is a cef ixime oral suspension powder patent centered on a specific reconstituted concentration (100 mg/mL) and bioequivalence to a 200 mg/5 mL cefixime trihydrate marketed suspension under fast and fed conditions.
• Dependent claims enumerate allowed excipient classes (diluents, sweeteners, viscosity agents, dispersing agents, flavors, preservatives) using “selected from” lists that align with common pediatric suspension formulating materials.
• Method claims (8 and 9) cover defined infectious indications (otitis media, pharyngitis, tonsillitis, bronchitis types, uncomplicated UTI, gonorrhea).
• Practical enforcement depends on whether an accused product’s reconstitution potency and fed/fast BE performance match the claim’s equivalence requirement.

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FAQs

1. Can a cefixime oral suspension avoid US 9,233,112 by changing excipients but keeping the same PK profile?
   Likely not if it still meets the claim 1 concentration and BE requirements; dependent excipient changes mostly affect dependent claims 2-7, not necessarily claim 1.

2. Is meeting FDA BE requirements sufficient to trigger infringement risk under US 9,233,112?
   The claim requires BE to a described comparator under fast and fed; if the FDA BE evidence corresponds, infringement risk rises, but the ultimate question is claim mapping.

3. Does US 9,233,112 require the accused product to be cefixime trihydrate?
   The comparator is trihydrate; the provided claim text requires “cef ixime” in the powder, with BE to the trihydrate comparator.

4. Do the method claims protect off-label use for indications not listed in claims 8 and 9?
   Based on the provided claim text, protection is limited to the enumerated indications.

5. What is the strongest noninfringement lever for a generic challenger of US 9,233,112?
   A credible failure to meet the claim’s required 100 mg/mL reconstitution and/or fast/fed BE to the specified marketed suspension.

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References

1. Provided claim text for US Patent 9,233,112 (user-supplied).

Drugs Protected by US Patent 9,233,112

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Lupin Ltd	SUPRAX	cefixime	FOR SUSPENSION;ORAL	202091-001	Feb 20, 2013	AB	RX	Yes	Yes	9,233,112		Y			METHODS FOR TREATING BACTERIAL INFECTIONS

Foreign Priority and PCT Information for Patent: 9,233,112

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
India	330/KOL/2006	Apr 13, 2006

International Family Members for US Patent 9,233,112

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Germany	112007000920
World Intellectual Property Organization (WIPO)	2007119249