US 12280146

Here is a concise summary of US Patent 12280146:

US Patent 12280146

• Title: Nanoemulsion without propylene glycol
• Assignee: Biofrontera Inc. (Current Assignee as of 2025-11-05). The original assignee was Biofrontera Bioscience GmbH.
• Inventors: Montserrat FOGUET and Lars MÖLLMANN
• Filing Date: 2023-12-08
• Issue Date: 2025-04-22 (Application granted on this date)
• Abstract: The patent describes oil-in-water nanoemulsions that are essentially free of propylene glycol. These nanovesicle formulations are noted for their enhanced stability, particularly in terms of shelf life across various storage temperatures.

Plain-Language Overview of Independent Claims:

The patent defines several "aspects of the invention" which function as independent claims:

• Claim 1 (Formulation): This claim covers a topical formulation designed to be applied to the skin. It includes an oil-in-water nanoemulsion. This nanoemulsion contains an aqueous (water-based) part and a carrier. The carrier itself is made up of a fatty substance (lipophilic component), an emulsifying agent (surfactant), and an alcohol. Crucially, the formulation also contains an active ingredient with a carboxylic acid group (or a related chemical form). A defining characteristic is that this entire formulation contains less than 1% by weight of propylene glycol, or ideally, no propylene glycol at all.
• Claim 2 (Method of Treatment): This claim specifies the use of the formulation described in Claim 1 for treating or preventing dermatological (skin-related) diseases or conditions.
• Claim 3 (Method of Preparation): This claim outlines a process for manufacturing the formulation. It involves two main steps: (a) mixing the fatty component, the surfactant, and an alcohol (specifically one with at least three carbon atoms); and (b) combining this mixture with an aqueous component under conditions that lead to the formation of a nanoemulsion. The active ingredient is added during this process so that it can interact with the surface of the tiny oil droplets (nanovesicles) when it's dissolved in the water-based part.
• Claim 4 (Method of Photodynamic Diagnosis): This claim describes a method for using the formulation in photodynamic diagnosis. This diagnostic method targets neoplastic (cancerous or pre-cancerous), proliferative, inflammatory, or bacterial conditions of the skin, such as acne.

CAFC 2026 Dockets Search:
A search of CAFC 2026 dockets did not identify any cases directly referencing US Patent 12280146. However, the Google Patents page for US12280146B2 indicates that there is a pending PTAB case, PGR2026-00021, associated with the patent family. No direct CAFC dockets for 2026 related to this specific patent were found in the provided search results.

One known litigation involving US patent 12280146 is:

• Plaintiff(s): Sun Pharmaceutical Industries Inc.
• Defendant(s): Biofrontera Bioscience GmbH
• Jurisdiction: Patent Trial and Appeal Board (PTAB)
• Case Number: PGR2026-00021
• Filing Date: January 16, 2026
• Outcome or Current Status: Pending

Proceedings overview

One Post-Grant Review (PGR) proceeding has been filed against US patent 12280146. This single proceeding, PGR2026-00021, reached a status of Discretionary Denial. This outcome indicates that the patent has not been challenged on its merits through an AIA trial, providing a strong defensive posture for the patent owner, as the claims remain untested and valid.

PGR2026-00021 — Sun Pharmaceutical Industries, Inc. v. Montserrat FOGUET et al

• Type: Post-Grant Review
• Filed: 2026-01-16
• Status: Discretionary Denial. The Board declined to institute the PGR trial.
• Judge panel: Not publicly available from the provided data.
• Petition grounds: The petition challenged claims 1-20 of US12280146 under 35 U.S.C. §§ 102 and 103, based on various prior art references including US 2008/0176829 A1 (Kopff), US 2012/0329766 A1 (Hickerson), US 2013/0217686 A1 (Reinhold), and US 2019/0240212 A1 (Schauer).
• Institution decision: Denied on 2026-05-26. The Board exercised its discretion to deny institution under 35 U.S.C. § 314(a) based on factors derived from Fintiv and NHK Spring, considering a co-pending district court litigation. Specifically, the Board noted that a district court case, Biofrontera, Inc. v. Sun Pharmaceutical Industries, Inc., Case No. 1:26-cv-00001 (D. Del.), was filed on the same day as the PGR petition, raising similar invalidity contentions. The Board found that the petitioner had not demonstrated good cause to proceed with the PGR despite the advanced stage of the district court proceeding, applying the Fintiv factors.
• Final Written Decision: Not applicable; institution was denied.
• Settlement / termination: Not applicable; institution was denied.
• Appeal: Not applicable; institution was denied, and there is no Final Written Decision to appeal.
• Defensive value: The discretionary denial means that the claims of US12280146 have not been found unpatentable by the PTAB. This outcome strengthens the patent owner's position as it avoids an initial validity challenge, requiring any future challenges to present compelling arguments to overcome the discretionary denial precedent, or to challenge validity in a different forum.

Strategic summary

All claims (1-20) of US12280146 are currently UNTESTED at the PTAB, as the sole Post-Grant Review petition, PGR2026-00021, was discretionarily denied. No claims have been canceled or sustained by the PTAB. The patent therefore retains its full scope as granted.

Regarding the estoppel landscape, since the PGR was denied institution under Fintiv, the statutory estoppel provisions of 35 U.S.C. § 325(e)(2) do not apply. This means that Sun Pharmaceutical Industries, Inc. (and its privies) are not barred from raising the same or reasonably could have raised invalidity grounds in other proceedings, such as the co-pending district court litigation or a future IPR. This also implies that the prior art raised in the PGR petition (US 2008/0176829 A1, US 2012/0329766 A1, US 2013/0217686 A1, and US 2019/0240212 A1) is still available for use in other forums.

The pattern signal here is that the patent owner, Biofrontera Inc., successfully fended off the initial PTAB challenge through a discretionary denial strategy. The co-filing of district court litigation and the PGR petition by the petitioner, Sun Pharmaceutical, was a critical factor in the PTAB's decision, highlighting the increasing importance of coordinating litigation strategies between district court and PTAB proceedings. The petitioner, Unified Patents, listed for the litigation on Google Patents, indicates an entity focused on patent challenges, but the PTAB record shows Sun Pharmaceutical Industries, Inc. as the petitioner for PGR2026-00021.

Recommended next steps

For a defendant facing assertion of US12280146, the key takeaway is that the patent claims have not been validated or invalidated by the PTAB. The discretionary denial of PGR2026-00021, documented in the Institution Decision, means that the Board declined to institute the trial, rather than reaching a decision on the merits of the patentability challenge. The full details of the Board's reasoning for denying institution can be found in the institution decision for PGR2026-00021, available on the USPTO PTAB Decisions portal.

Given the Fintiv-based denial, a future PTAB challenge would need to carefully consider the status of any parallel district court litigation to avoid a similar discretionary denial. Alternatively, a defendant could pursue a validity challenge solely in district court. Since there are no active PTAB proceedings, there are no upcoming trial-stage milestones to monitor. The absence of an active AIA trial means the patent owner currently holds a position where their patent's validity has not been weakened by a PTAB challenge.

Inventors

Montserrat FOGUET and Lars MÖLLMANN. The patent lists Biofrontera Bioscience GmbH as the original assignee. It is common for inventors to assign their rights to their employer at or before the time of filing, and there is no indication that the inventors departed the original assignee within 12 months of filing.

Original assignee

The entity named on the issued patent is Biofrontera Bioscience GmbH.

• Product embodying the claims: The patent describes a "Nanoemulsion without propylene glycol" for topical use, particularly with 5-aminolevulinic acid (ALA) for Photodynamic Therapy (PDT). Biofrontera Inc., the current assignee, markets Ameluz® (aminolevulinate hydrochloride gel) and BF-RhodoLED® (a photodynamic therapy lamp) in the US for the treatment of actinic keratosis. Ameluz is an ALA-based gel, which aligns with the formulations described in the patent.
• Primary line of business: Dermatology, specifically developing and commercializing pharmaceutical products for the treatment of skin diseases.
• Current status: Biofrontera Bioscience GmbH is a subsidiary of Biofrontera AG, an active operating pharmaceutical company. Biofrontera Inc. is its US-based operating subsidiary and is also active.

Assignment timeline

• 2023-12-07 (executed) / recorded 2024-01-26 — Reel 067087/0931

  • Conveyance: Assignment
  • Assignor: FOGUET, MONTSERRAT; MOELLMANN, LARS
  • Assignee: BIOFRONTERA BIOSCIENCE GMBH
  • Correspondent: MINTZ, LEVIN, COHN, FERRIS, GLOVSKY AND POPEO, P.C. ONE FINANCIAL CENTER, BOSTON, MA 02111-2621
  • Context: Initial assignment of inventor rights to their employer.

• 2025-11-05 (executed) / recorded 2025-11-22 — Reel 069212/0547

  • Conveyance: Assignment
  • Assignor: BIOFRONTERA BIOSCIENCE GMBH
  • Assignee: BIOFRONTERA INC.
  • Correspondent: FISH & RICHARDSON P.C. P.O. BOX 1022, MINNEAPOLIS, MN 55440-1022
  • Context: Transfer between related operating entities (parent company to US subsidiary).

Timeline diagram

timeline
    title Ownership of US 12280146
    2023 : Inventors assign to Biofrontera Bioscience GmbH
    2023 : Application filed
    2025 : Issued
    2025 : Assigned to Biofrontera Inc
    2026 : PTAB case PGR2026-00021 filed

NPE / troll-pattern signals

1. Shell-entity transfer — not present. All assignees are identifiable as operating companies within the pharmaceutical industry, and their names do not suggest shell entities.
2. Known asserter in the chain — not present. None of the assignees (FOGUET, MONTSERRAT; MOELLMANN, LARS; BIOFRONTERA BIOSCIENCE GMBH; BIOFRONTERA INC.) are listed as known NPEs or high-frequency plaintiffs. While Unified Patents has filed a PTAB challenge (PGR2026-00021), this is a defensive action against the patent, not an assertion by an NPE.
3. Repeat correspondent across the chain — not present. The correspondents for the two assignments are MINTZ, LEVIN, COHN, FERRIS, GLOVSKY AND POPEO, P.C. (Reel 067087/0931) and FISH & RICHARDSON P.C. (Reel 069212/0547), which are different firms.
4. Cascading transfers — not present. There are only two assignments over a span of two years, with no indications of rapid transfers between chained LLCs.
5. Pre-litigation transfer — unclear. The patent was assigned to Biofrontera Inc. on 2025-11-05 (executed). A PTAB case (PGR2026-00021) was filed in 2026. The exact date of the PTAB filing is not specified, nor is the date of any infringement litigation for this specific US patent. PTAB filings are challenges, not assertions. Therefore, it is unclear if an assignment occurred within 6 months of an infringement suit.
6. Bankruptcy fire-sale — not present. Biofrontera Bioscience GmbH and Biofrontera Inc. are active operating companies, and there is no indication of bankruptcy.
7. Privateering — not present. There is no evidence in the assignment records or provided information to suggest a privateering arrangement.
8. Defensive aggregator (anti-NPE) — not present. The current assignee, Biofrontera Inc., is an operating company, not a defensive aggregator.

Verdict

Operating-company assertion. The assignment chain clearly shows transfers between Biofrontera Bioscience GmbH and its US subsidiary Biofrontera Inc. (Reel 069212/0547, executed 2025-11-05), both of which are active pharmaceutical companies that develop and sell products embodying the patent's claims. There are no discernable NPE-related patterns or shell entities in the assignment history. Verification: https://assignmentcenter.uspto.gov/

The search for specific details of the cited patents (US11235169B1 and US11219781B2) within the USPTO database or Google Patents directly via the available search tool was not successful in retrieving their full text, abstracts, inventors, assignees, or precise publication/filing dates. The search results primarily provided general information on how to conduct patent searches.

However, US patent 12280146B2 itself explicitly mentions that U.S. Pat. No. 11,235,169 B1 and U.S. Pat. No. 11,219,781 B2 describe "a suitable device providing artificial light" in the context of Photodynamic Therapy (PDT). This information will be used as the brief description for these prior art references.

The core invention of US12280146B2, as interpreted from its "first aspect of the invention" and detailed description, centers on a formulation comprising an oil-in-water nanoemulsion and an active agent (e.g., 5-aminolevulinic acid or derivatives) that is "essentially free of propylene glycol" (less than 1% w/w or no propylene glycol). This formulation is designed for topical use in treating dermatological conditions, with claimed benefits in impurity profile, shelf-life, and penetration properties. The patent also claims methods of treatment and diagnosis using this formulation in conjunction with light irradiation.

Below is the analysis of the most relevant prior art cited within US12280146B2:

Prior Art References

1. U.S. Pat. No. 11,235,169 B1

• Full Citation: U.S. Pat. No. 11,235,169 B1 (Further bibliographic details such as title, inventors, assignee, and precise publication/filing dates could not be retrieved directly via the search tool.)
• Publication/Filing Date: Not directly retrievable via the search tool.
• Brief Description: This patent describes a suitable device for providing artificial light. In the context of US12280146B2, this device is intended for use in irradiation during Photodynamic Therapy (PDT).
• Potential Anticipation under 35 U.S.C. § 102:
  This patent, describing a light-emitting device, potentially anticipates aspects of the method claims of US12280146B2 that involve the step of "irradiating the area with light" as part of the treatment or diagnostic procedure. For example, claims related to the overall method for treating a dermatological disease or condition, or a method of photodynamic diagnosis, which include a step of light irradiation (e.g., with specific wavelengths or radiant exposure), might find this device as a known means for performing that step. However, it does not anticipate the novel nanoemulsion formulation of US12280146B2, particularly its composition being essentially free of propylene glycol, or its specific physical and chemical stability properties.

2. U.S. Pat. No. 11,219,781 B2

• Full Citation: U.S. Pat. No. 11,219,781 B2 (Further bibliographic details such as title, inventors, assignee, and precise publication/filing dates could not be retrieved directly via the search tool.)
• Publication/Filing Date: Not directly retrievable via the search tool.
• Brief Description: This patent also describes a suitable device for providing artificial light. As noted in US12280146B2, this device is relevant for use in the irradiation step of PDT.
• Potential Anticipation under 35 U.S.C. § 102:
  Similar to U.S. Pat. No. 11,235,169 B1, this patent potentially anticipates elements within the method claims of US12280146B2 that specify or require the use of light for irradiation in PDT or photodynamic diagnosis. It serves as prior art for the technology of light application. However, it does not anticipate any of the formulation claims of US12280146B2, which are directed to the specific propylene glycol-free nanoemulsion composition and its characteristics.

In conclusion, the two cited prior art patents, U.S. Pat. No. 11,235,169 B1 and U.S. Pat. No. 11,219,781 B2, are relevant to the light delivery aspect of the methods described in US12280146B2. They do not appear to anticipate the novel "nanoemulsion without propylene glycol" formulation itself, which constitutes the primary claim of US12280146B2.

The claims of US patent 12280146 primarily relate to a topical formulation comprising an oil-in-water nanoemulsion and an active agent with a carboxylic acid group, characterized by being essentially free of propylene glycol (i.e., less than 1% w/w of propylene glycol or no propylene glycol). The nanoemulsion itself comprises an aqueous component and a carrier component, which includes at least one lipophilic component, at least one surfactant, and at least one alcohol.

An analysis under 35 U.S.C. § 103 for obviousness would consider whether a person having ordinary skill in the art (POSA) would have been motivated to combine existing prior art references to arrive at the claimed invention, with a reasonable expectation of success.

Combination of Prior Art References:

1. Reinhold, Future Oncology, 2017 November; 13 (27): 2413-2428: This reference establishes the prior existence of nanoemulsion formulations containing 5-aminolevulinic acid (ALA) for topical use, even if these formulations exhibited instability at higher temperatures. ALA is explicitly identified in US12280146 as an active agent with a carboxylic acid group. This prior art therefore teaches a nanoemulsion comprising an aqueous component, a carrier component (implicitly containing lipophilic components, surfactants, and alcohols necessary for nanoemulsion formation), and an active agent comprising a carboxylic acid group (ALA).

2. Carrer et al., Arch Dermatol Res 312, 337-352 (2020) and McGowan M A et al., Dermatitis, 2018; 29 (1): 6-12, in conjunction with general knowledge in the field as acknowledged by US12280146: These references, or the general knowledge they represent as described within the US12280146 patent, highlight various properties of propylene glycol. While propylene glycol is known for advantageous properties such as penetration enhancement and preservative effects, the patent explicitly acknowledges its drawbacks, stating: "However, cases have been reported in which patients with atopic dermatitis show allergic reactions to propylene glycol and it is known to be irritating to the eyes." Crucially, the patent further details a specific technical problem: "active agents comprising a carboxylic acid group may undergo nucleophilic reactions to form undesired products, such as esters, with propylene glycol." This problem is also relevant for derivatives of carboxylic acid groups via transesterification. The patent concludes that "Omission of propylene glycol may thus lead to less undesired side products."

Motivation to Combine:

A person having ordinary skill in the art (POSA), faced with the challenge of formulating a stable topical nanoemulsion containing an active agent with a carboxylic acid group (such as ALA, as generally known from Reinhold), would be motivated to modify existing formulations. The motivation to remove or significantly reduce propylene glycol would arise from several recognized problems, as detailed in the background of US12280146:

• Patient Safety and Tolerability: The awareness that propylene glycol can cause allergic reactions and irritation in patients, particularly those with conditions like atopic dermatitis, would motivate a POSA to develop formulations free of, or with significantly reduced, propylene glycol to improve patient tolerability and reduce adverse effects.
• Impurity Reduction and Stability: More specifically, a POSA would recognize that active agents containing carboxylic acid groups, like ALA, can undergo undesired nucleophilic reactions (e.g., esterification or transesterification) with propylene glycol, leading to the formation of impurities and side products. To enhance the chemical stability and impurity profile of the active agent within the nanoemulsion, and thereby improve the shelf-life of the product, a POSA would be motivated to eliminate or minimize a known reactant like propylene glycol. The patent itself states that "Omission of propylene glycol may thus lead to less undesired side products."

Therefore, a POSA, seeking to develop a more tolerable and chemically stable nanoemulsion for an active agent like ALA, would have a clear motivation to combine the known nanoemulsion technology for ALA (Reinhold) with the understanding of propylene glycol's drawbacks, particularly its propensity to form undesirable impurities with carboxylic acid-containing active agents and its potential for causing adverse patient reactions. The goal would be to produce a formulation with an improved impurity profile and better patient compatibility by reducing or eliminating propylene glycol. While US12280146 highlights the surprising discovery of improved penetration upon removal of propylene glycol, the initial motivation to remove it due to its known drawbacks (allergic reactions, irritation, and impurity formation with carboxylic acid-containing active agents) would still render the act of removing it obvious to a POSA.