Details for Patent: 9,750,711

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Which drugs does patent 9,750,711 protect, and when does it expire?

Patent 9,750,711 protects ABSORICA LD and is included in one NDA.

This patent has eight patent family members in eight countries.

Summary for Patent: 9,750,711

Title:	Low dose oral pharmaceutical composition of isotretinoin
Abstract:	The present invention provides a low dose oral pharmaceutical composition of isotretinoin having reduced food effect, in particular no food effect. The present invention further relates to a process for preparing the oral pharmaceutical composition of the present invention.
Inventor(s):	Harish Kumar Madan, Rathinasabapathy VENKATESHWARAN, Sumit Madan, Ravi Kochhar
Assignee:	Sun Pharmaceutical Industries Ltd
Application Number:	US15/444,571
Patent Claim Types: see list of patent claims	Composition; Formulation; Device; Dosage form;

United States Patent 9,750,711: Isotretinoin Capsule Claims, Patent Scope, and Generic Risk

US Patent No. 9,750,711 protects an isotretinoin capsule defined primarily by pharmacokinetic performance, food-effect behavior, particle size, composition structure, surfactant content, and rapid dissolution. The patent does not claim isotretinoin as a chemical compound. Its commercial relevance depends on whether a competing product reproduces the claimed exposure profile and formulation characteristics, not merely whether it contains isotretinoin.

The strongest protection is concentrated in claim 1, which requires a capsule that delivers a specified fasting mean Cmax over a specified dose range. Claims 2 and 3 add AUC and fed/fasted requirements. Claims 4 through 9 narrow the formulation architecture.

What does US Patent 9,750,711 cover?

The patent covers an oral isotretinoin capsule with a defined in-human pharmacokinetic profile under fasting conditions. The core limitations are:

Limitation	Claim requirement
Dosage form	Oral capsule
Active ingredient	Isotretinoin
Excipients	Pharmaceutically acceptable excipient
Dose tested	About 0.4 mg/kg to about 1.6 mg/kg
Pharmacokinetic endpoint	Mean Cmax of about 9 to about 40 ng/mL/mg
Additional exposure limitation	AUC0-t of about 125 to about 500 ng·h/mL/mg
Food effect	Mean fed/fasted AUC0-t ratio of about 0.9 to about 1.40
Physical form	Dispersion filled into capsules
Particle size	Micronized isotretinoin with D90 below 30 micrometers
Drug loading	About 5.5% to about 15% by total composition weight
Surfactants	Broad classes and named surfactants
Dissolution	At least 50% released in 15 minutes under the stated USP Type II conditions

The claims combine composition limitations with performance limitations. A product may contain the same active ingredient and still avoid infringement if it falls outside a required pharmacokinetic, particle-size, food-effect, loading, or dissolution limitation. Conversely, a formulation that uses different excipients may still present risk if it satisfies every limitation of a claim.

How broad is independent claim 1?

Claim 1 is broad in formulation terms but narrow in measurable performance terms.

It does not require:

• A specific surfactant;
• A particular oil phase;
• A named lipid excipient;
• A particular capsule shell;
• Micronized isotretinoin;
• A specified dissolution method;
• A specified fed/fasted ratio.

It does require an isotretinoin capsule that produces the claimed mean Cmax when administered across the stated dose range under fasting conditions. The claim also requires a pharmaceutically acceptable excipient, but it does not prescribe a closed formulation recipe.

This structure creates two competing effects:

1. The absence of a fixed excipient formula expands the claim across formulation designs.
2. The pharmacokinetic limitation creates a substantial proof burden because infringement depends on human clinical data or a legally sufficient basis for establishing the claimed Cmax.

The phrase “about” introduces numerical flexibility. Its scope would ordinarily depend on intrinsic evidence, the patent specification, prosecution history, technical usage, and the court’s interpretation. A competitor at 8.9 or 40.2 ng/mL/mg cannot be assessed solely by arithmetic. The legally relevant range may include a tolerance around the stated endpoints, but the permitted tolerance is not automatically 5% or 10%.

What do claims 2 and 3 add?

Claim 2: AUC exposure

Claim 2 requires the claim 1 capsule to produce an AUC0-t value of approximately 125 to 500 ng·h/mL/mg under fasting conditions.

AUC is an exposure measure reflecting the amount of drug reaching systemic circulation over time. Claim 2 narrows claim 1 by requiring both:

• The Cmax range in claim 1; and
• The AUC0-t range in claim 2.

A competing product that meets the Cmax requirement but produces an AUC outside the claim 2 range would not infringe claim 2, although it could still implicate claim 1.

Claim 3: Limited food effect

Claim 3 adds a fed/fasted AUC0-t ratio of approximately 0.9 to 1.40.

This limitation is commercially significant because conventional isotretinoin products have historically been sensitive to food intake. A product with a fed/fasted ratio close to 1 is designed to reduce the dependence of absorption on administration with food. The claim therefore targets a clinically meaningful product attribute rather than only a manufacturing parameter.

A product with a fed/fasted ratio above 1.40 or below 0.90 may avoid claim 3, subject to the interpretation of “about.” It could remain within claims 1 and 2 if its fasting Cmax and AUC satisfy those claims.

What formulation features are protected?

Dispersion-filled capsules

Claim 4 requires the composition to be in the form of a dispersion that is filled into capsules. The claim does not expressly limit the dispersion to a particular type.

Potential dispersion categories may include:

• Solid-in-liquid dispersions;
• Lipid or self-emulsifying dispersions;
• Suspensions;
• Surfactant-containing dispersions;
• Dispersions containing micronized isotretinoin.

The claim language does not necessarily require that the final capsule remain visibly heterogeneous. The relevant question would be how “dispersion” is defined in the specification and prosecution record.

Micronized isotretinoin

Claim 5 requires a D90 particle size below 30 micrometers. D90 means that 90% of the measured particle-size distribution is at or below the specified threshold, subject to the measurement method.

This limitation creates several technical and litigation issues:

• The patent’s particle-size measurement method may control or materially affect the result.
• Laser diffraction, microscopy, and other methods can produce different distributions.
• Agglomeration during formulation may affect measured particle size.
• A supplier’s certificate of analysis may not establish the D90 of the finished dispersion.
• The claim does not state a lower limit, so nanomaterial-scale particles may fall within the language if the other limitations are met.

Particle size is one of the more practical design-around variables. A competitor may use a larger particle distribution, a different solubilization technology, or a molecularly dispersed system. That approach would not eliminate risk under claim 1 if the final product still satisfies the claimed pharmacokinetic profile.

Isotretinoin loading

Claim 6 requires isotretinoin to constitute approximately 5.5% to 15% of the total composition by weight.

This is a narrower composition claim. It may be relevant to capsule fill weight, manufacturing scale-up, and dose strength. The claim does not identify the dose per capsule. A 10 mg capsule and a 40 mg capsule could both potentially fall within the claim if the percentage of isotretinoin in the total composition is within the stated range.

The percentage should be calculated against the total composition weight rather than only the non-shell fill weight, unless the specification provides a different basis.

Surfactants

Claim 7 requires a surfactant. Claim 8 identifies broad surfactant categories and named examples, including:

• Anionic, cationic, and nonionic surfactants;
• Sorbitan fatty acid esters;
• Polysorbates;
• Polyethylene glycol nonylphenyl ethers;
• Dioctyl sodium sulfosuccinate;
• Sodium lauryl sulfate;
• Lecithin;
• Propylene glycol fatty acid esters;
• Glycerol fatty acid esters;
• Poloxamers;
• Mixtures of these materials.

Claim 8 is narrower than claim 7 because it recites a defined group. A formulation using a surfactant outside the listed group might avoid claim 8 while remaining exposed under claim 7 and, potentially, claim 1.

What does claim 9 protect?

Claim 9 requires release of at least 50% of isotretinoin within 15 minutes under a highly specific dissolution protocol:

• USP Type II apparatus;
• Paddle at 75 rpm;
• 900 mL of pH 7.4 phosphate buffer;
• 70 mg/L pancreatin;
• 4.5% LDAO as a 30% solution;
• Spiral-coated sinker.

This is a product-performance limitation, not simply a requirement to perform a dissolution test during quality control. The test conditions form part of the claim.

Claim 9 is potentially important because it links rapid in-vitro release to a formulation intended to improve isotretinoin dispersion and absorption. It is also technically vulnerable to testing disputes. Relevant variables include:

• Exact LDAO concentration and preparation;
• Pancreatin activity;
• Buffer preparation and pH control;
• Sinker design and coating;
• Paddle alignment and speed;
• Sampling and assay method;
• Capsule-shell behavior;
• Lot-to-lot variation.

A product that releases 50% or more in 15 minutes under ordinary USP dissolution conditions may not meet claim 9 if it fails under the specifically recited pancreatin/LDAO method.

How do the claims relate to one another?

The claim structure creates several infringement pathways.

Product characteristic	Possible claim exposure
Capsule with isotretinoin and excipient, claimed fasting Cmax	Claim 1
Claim 1 profile plus fasting AUC	Claim 2
Claim 2 profile plus fed/fasted AUC ratio	Claim 3
Dispersion filled into a capsule	Claim 4
Micronized isotretinoin with D90 below 30 micrometers	Claim 5
Isotretinoin loading of approximately 5.5% to 15%	Claim 6
Any qualifying surfactant	Claim 7
Listed surfactant or mixture	Claim 8
Specified rapid dissolution result	Claim 9

Claims 2 through 9 are dependent claims. A dependent claim incorporates every limitation of the claim from which it depends. A product must therefore satisfy claim 1 before it can infringe any dependent claim that depends directly or indirectly on claim 1.

When does US Patent 9,750,711 lose exclusivity?

The patent was granted on September 5, 2017. The grant date alone does not determine the expiration date. Under the standard US patent-term framework, the relevant endpoint is generally 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and applicable priority claims.[1]

Because the supplied materials do not establish the patent’s earliest priority date, patent-term adjustment, terminal disclaimer status, or any patent-term extension, a definitive expiration date cannot be calculated from the claims alone.

The patent is not a new chemical entity patent. Isotretinoin has been marketed for decades, so the principal exclusivity value of US 9,750,711 is formulation and performance protection rather than active-ingredient exclusivity.

What is the Orange Book status of US 9,750,711?

A patent number is relevant to Orange Book protection only if it is listed for an approved drug product by the relevant NDA holder and remains listed under FDA rules. Patent claims alone do not establish Orange Book listing.

The relevant regulatory questions are:

1. Whether US 9,750,711 is listed for an approved isotretinoin NDA;
2. Which strengths and dosage forms are associated with the listing;
3. Whether the listing covers the drug product, method of use, or formulation;
4. Whether the patent has been delisted, expired, or removed;
5. Whether an ANDA applicant must make a Paragraph IV certification.

FDA’s Orange Book identifies patents submitted by NDA sponsors, but it does not independently decide infringement or validity.[2] A listed patent can still be challenged through a Paragraph IV certification, and an unlisted formulation patent may still be asserted outside the automatic Orange Book litigation framework.

What Paragraph IV challenges could target this patent?

An ANDA applicant seeking approval for an isotretinoin capsule could address the patent through:

• Paragraph IV certification that the patent is invalid, unenforceable, or will not be infringed;
• A section viii statement, if the relevant patent claims only an unapproved method of use;
• A Paragraph III certification if the applicant accepts delay until patent expiration;
• A formulation design intended to avoid the claimed limitations.

For this patent, a Paragraph IV challenge could focus on:

Anticipation

The challenger would need to identify a single prior-art reference disclosing every limitation of the asserted claim, including the specified pharmacokinetic ranges or dissolution protocol where applicable.

Obviousness

The challenger could argue that it would have been obvious to combine:

• Micronized isotretinoin;
• A surfactant or dispersion system;
• Capsule delivery;
• A food-effect reduction strategy;
• Rapid dissolution testing.

The numerical PK ranges may complicate the analysis. A challenger would need evidence that the claimed ranges were predictable, inherent, or the result of routine optimization.

Written description and enablement

The independent claim covers a broad range of excipient systems and PK outcomes. A validity challenge could examine whether the specification supports the full breadth of the claimed Cmax, AUC, food-effect, particle-size, surfactant, and dissolution combinations.

Indefiniteness

Potential issues include:

• The meaning of “about” at the numerical endpoints;
• Whether the Cmax and AUC values are normalized per milligram in a technically consistent way;
• The meaning of “mean” and the relevant study population;
• The required statistical treatment of fed/fasted ratios;
• The reproducibility of the LDAO and pancreatin dissolution method.

These arguments would depend on the specification and prosecution history, not the claim text alone.

What generic launch risks exist?

The principal generic risk is that a conventional isotretinoin capsule may be commercially bioequivalent to the reference product while also falling within the patent’s PK ranges. Bioequivalence does not itself establish noninfringement.

A generic developer would likely evaluate several design paths:

Strategy	Potential benefit	Principal risk
Match the reference product closely	Simplifies development and approval	May reproduce all claimed PK and formulation limitations
Use a different particle-size distribution	May avoid claim 5	Could still satisfy claim 1 through equivalent exposure
Avoid listed surfactants	May avoid claim 8	Claim 7 may remain relevant
Use a non-dispersion formulation	May avoid claim 4	Cmax and AUC claims may remain
Alter food-effect behavior	May avoid claim 3	Could impair clinical performance or leave claims 1 and 2 intact
Use slower dissolution	May avoid claim 9	May affect bioequivalence and product performance
Challenge validity under Paragraph IV	May enable earlier launch	Creates litigation and potential 30-month stay exposure

The patent is therefore more difficult to design around at the claim 1 level than at the dependent-claim level. A formulation can avoid micronization, a named surfactant, or the precise dissolution condition and still face risk if it satisfies the fasting Cmax requirement.

How strong is the patent estate?

US 9,750,711 has moderate strategic strength based on the supplied claims.

Strengths

• Claim 1 is not tied to a single excipient recipe.
• The claims cover both formulation structure and clinical performance.
• The fed/fasted limitation targets a commercially valuable isotretinoin attribute.
• The dependent claims provide multiple technical fallback positions.
• The claims can reach products using different excipients if the performance profile is reproduced.

Weaknesses

• Infringement may require access to confidential human PK data.
• “About” ranges may create claim-construction disputes.
• The patent does not claim isotretinoin itself.
• The broad formulation scope may invite written-description, enablement, and obviousness challenges.
• Dependent claims are vulnerable to formulation changes involving particle size, surfactant selection, drug loading, or dissolution behavior.
• The exact value of the patent depends heavily on Orange Book listing and the remaining statutory term.

The estate is strongest against a generic that deliberately reproduces the reference product’s dispersion, micronized API, surfactant system, food-independent absorption, and rapid release. It is weaker against a product using a materially different delivery platform that demonstrates a distinct PK and dissolution profile.

What litigation and settlement issues affect the patent?

No litigation, settlement, or Paragraph IV outcome can be established from the claim text supplied. The relevant legal record would include:

• ANDA litigation under the Hatch-Waxman Act;
• District court claim-construction decisions;
• Inter partes review petitions or final written decisions;
• Patent-term and Orange Book records;
• Settlement agreements with generic applicants;
• Any covenant not to sue or license;
• FDA approval dates for competing isotretinoin capsules.

A settlement could impose a launch date earlier than the patent’s nominal expiration. The commercial launch date therefore cannot be inferred from the patent term alone.

How does US 9,750,711 compare with other isotretinoin protection?

Isotretinoin exclusivity is divided among several categories:

Protection category	Relevance to isotretinoin
Active-ingredient patent	Generally weak because isotretinoin is an old molecule
Formulation patent	High relevance for lipid, dispersion, micronized, or surfactant systems
PK patent	High relevance where absorption is less food-dependent
Method-of-use patent	Potentially relevant to acne treatment and dosing
Manufacturing patent	May protect micronization, dispersion preparation, or encapsulation
Regulatory exclusivity	Depends on the approved product and NDA history
REMS-related controls	May affect commercialization but are not patent exclusivity

There is no biosimilar pathway for isotretinoin because it is a synthetic small molecule. Competitive entry would proceed through an ANDA or, for a materially different product, an NDA pathway.

Key Takeaways

• US 9,750,711 is a formulation and pharmacokinetic patent, not an isotretinoin compound patent.
• Claim 1 is the principal barrier because it covers a capsule defined by fasting Cmax rather than by a fixed excipient formula.
• Claims 2 and 3 add AUC and reduced food-effect requirements.
• Claims 4 through 9 cover dispersion architecture, micronized API, drug loading, surfactants, and rapid dissolution.
• A generic may avoid individual dependent claims while still facing claim 1.
• Bioequivalence does not automatically eliminate infringement risk.
• The patent’s enforceable expiration date cannot be determined from the supplied claims and grant date alone.
• Orange Book listing, patent-term adjustment, litigation history, and settlement terms are essential to quantify launch risk.
• The patent has its greatest commercial value against products that reproduce the reference product’s food-independent absorption and dispersion-based delivery system.

FAQs

Can a generic isotretinoin capsule infringe US 9,750,711 without using the same excipients?

Yes. Claim 1 is not limited to a named excipient combination. A different formulation may still infringe if it satisfies the capsule, isotretinoin, excipient, dose, fasting Cmax, and related claim limitations.

Does a fed/fasted ratio outside 0.9 to 1.40 avoid the entire patent?

No. It may avoid claim 3, but claims 1 and 2 could remain relevant if the product satisfies the claimed fasting Cmax and AUC ranges.

Is D90 below 30 micrometers required for every claim?

No. The micronized-particle limitation appears in claim 5. It is not required by claims 1 through 4 unless incorporated through claim dependency, and avoiding it does not necessarily avoid the broader PK claims.

Can a generic rely on ordinary bioequivalence testing to prove noninfringement?

No. Bioequivalence testing may provide relevant PK data, but noninfringement requires comparison against every limitation of the asserted claim. The study may not measure all required formulation or dissolution characteristics.

Does FDA approval confirm that a product does not infringe this patent?

No. FDA approval and patent infringement are separate issues. An ANDA may be approved subject to patent certifications, statutory stays, or a launch restriction, while infringement remains a matter for the courts.

References

1. United States Patent and Trademark Office. (2024). Manual of Patent Examining Procedure, Chapter 2700: Patent term. U.S. Department of Commerce.

2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. U.S. Department of Health and Human Services.

3. U.S. Food and Drug Administration. (2023). ABSORICA (isotretinoin) capsules prescribing information. Sun Pharmaceutical Industries, Inc.

4. United States Congress. (1984). Drug Price Competition and Patent Term Restoration Act of 1984, Pub. L. No. 98-417, 98 Stat. 1585.

5. United States Patent and Trademark Office. (2017). United States Patent No. 9,750,711. U.S. Department of Commerce.

Drugs Protected by US Patent 9,750,711

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Sun Pharm	ABSORICA LD	isotretinoin	CAPSULE;ORAL	211913-001	Nov 5, 2019		RX	Yes	No	9,750,711		Y
Sun Pharm	ABSORICA LD	isotretinoin	CAPSULE;ORAL	211913-002	Nov 5, 2019		RX	Yes	No	9,750,711		Y
Sun Pharm	ABSORICA LD	isotretinoin	CAPSULE;ORAL	211913-003	Nov 5, 2019		DISCN	Yes	No	9,750,711		Y
Sun Pharm	ABSORICA LD	isotretinoin	CAPSULE;ORAL	211913-004	Nov 5, 2019		RX	Yes	No	9,750,711		Y
Sun Pharm	ABSORICA LD	isotretinoin	CAPSULE;ORAL	211913-005	Nov 5, 2019		DISCN	Yes	No	9,750,711		Y
Sun Pharm	ABSORICA LD	isotretinoin	CAPSULE;ORAL	211913-006	Nov 5, 2019		RX	Yes	Yes	9,750,711		Y

Foreign Priority and PCT Information for Patent: 9,750,711

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
India	2827/DEL/2014	Oct 1, 2014

International Family Members for US Patent 9,750,711

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2015326489
Brazil	112017006779
Canada	2963206
European Patent Office	3200877
Japan	2017530149
Mexico	2017004312