Derivative works — US Patent 11021437

Defensive Disclosure and Prior Art Generation for Epinephrine Prodrug Delivery Systems

Publication Date: May 14, 2026
Reference Technology: The subject matter of US Patent 11,021,437, which describes epinephrine di-ester prodrugs formulated in a rapidly dissolving film for sublingual or buccal administration.
Objective: This document discloses novel derivative works, applications, and combinations of the reference technology to place them in the public domain, thereby precluding future patenting of these specific embodiments and obvious variations thereof.

Section 1: Material and Component Substitutions

Derivative 1.1: Multi-Laminate Film with Unidirectional Flow

Enabling Description: A pharmaceutical composition for buccal or sublingual delivery comprising a multi-laminate film. The film consists of three distinct layers: (1) An inner mucoadhesive layer comprising the epinephrine di-ester prodrug dispersed within a hydrophilic polymer matrix of polyethylene oxide (PEO) and Carbopol 974P to ensure prolonged contact with the mucosal surface. (2) A central drug-free layer of hydroxypropyl methylcellulose (HPMC) acting as a release-rate-controlling membrane. (3) An outer, non-permeable backing layer of ethyl cellulose, which prevents drug diffusion into the oral cavity and forces unidirectional absorption into the mucosal tissue. This architecture maximizes bioavailability by concentrating the drug flux towards the absorptive tissue. The prodrug itself is selected from the di-esters of epinephrine with L-valine or L-leucine, designed for cleavage by aminopeptidases present in the oral mucosa.

Mermaid Diagram:

graph TD
    subgraph Multi-Laminate Film Cross-Section
        A[Outer Backing Layer - Ethyl Cellulose];
        B[Central Control Layer - HPMC];
        C[Mucoadhesive Drug Layer - PEO, Carbopol, Prodrug];
    end
    C -- Mucoadhesion --> D((Buccal/Sublingual Mucosa));
    A -- Prevents Diffusion --> E((Oral Cavity / Saliva));
    B -- Controls Release --> C;
    C -- Unidirectional Drug Flux --> D;

Derivative 1.2: Electrospun Nanofiber Mat for Ultra-Rapid Dissolution

Enabling Description: A dosage form comprising an electrospun nanofiber mat for sublingual administration. The mat is produced by co-axial electrospinning. The core of the nanofiber consists of the epinephrine prodrug (e.g., 4-(1-hydroxy-2-(methylamino)ethyl)-1,2-phenylene bis(2,2,2-trifluoroacetate)) encapsulated within amorphous solid dispersion using a Soluplus® carrier. The shell of the nanofiber is a rapidly dissolving polymer such as pullulan or polyvinyl alcohol (PVA). This core-shell structure protects the sensitive prodrug from hydrolysis prior to administration. The extremely high surface-area-to-volume ratio of the nanofiber mat results in near-instantaneous dissolution (<5 seconds) upon contact with saliva, leading to a rapid release of the prodrug for absorption. The trifluoroacetate ester groups are chosen for their rapid hydrolysis rate due to the strong electron-withdrawing effect of fluorine.

Mermaid Diagram:

classDiagram
  class Nanofiber {
    +diameter: 100-500 nm
    +dissolutionTime: < 5s
  }
  class Core {
    +material: Soluplus®
    +payload: Epinephrine Trifluoroacetate Prodrug
  }
  class Shell {
    +material: Pullulan or PVA
  }
  Nanofiber "1" -- "1" Core : contains
  Nanofiber "1" -- "1" Shell : is coated by

Section 2: Operational Parameter Expansion

Derivative 2.1: Lyophilized Cryo-Stable Film for Extreme Environments

Enabling Description: A pharmaceutical formulation designed for stability in extreme temperature fluctuations (-80°C to +60°C), suitable for military or space exploration applications. The formulation begins as an aqueous solution of an epinephrine di-ester prodrug, a film-forming polymer (e.g., fish gelatin), and a cryoprotectant (e.g., trehalose at 10% w/v). This solution is cast into a mold and subjected to lyophilization (freeze-drying). The resulting dosage form is a highly porous, wafer-like film that is extremely low in residual water content (<1%), preventing degradation pathways. The trehalose forms a glassy matrix around the prodrug molecule, stabilizing its conformation. Reconstitution is instantaneous upon contact with saliva.

Mermaid Diagram:

flowchart TD
    A[Aqueous Solution: Prodrug, Gelatin, Trehalose] --> B{Freeze to -80°C};
    B --> C[Primary Drying: Sublimation under Vacuum];
    C --> D[Secondary Drying: Desorption of bound water];
    D --> E[Final Product: Porous Lyophilized Wafer];
    E -- Contact w/ Saliva --> F(Instant Dissolution & Drug Release);

Derivative 2.2: Nanoparticle-in-Film System for Pediatric Dosing

Enabling Description: A system for delivering precise, weight-based pediatric doses of epinephrine. The epinephrine prodrug is first encapsulated in solid lipid nanoparticles (SLNs) with a mean diameter of 200 nm, using Compritol® 888 ATO as the lipid matrix. These SLNs are then suspended in a film-forming solution containing sodium alginate. The resulting film is cast and dried. The final product is a large film sheet that is homogenous in its distribution of SLNs. A pharmacist or caregiver can cut the film to a precise size/weight corresponding to the pediatric patient's body weight, with the dose being directly proportional to the area of the film segment. The lipid encapsulation provides an additional taste-masking layer.

Mermaid Diagram:

graph LR
    subgraph Manufacturing
        A(Epinephrine Prodrug) --> B(Melted Compritol® 888);
        B --> C{High-Shear Homogenization};
        C --> D[Solid Lipid Nanoparticles];
    end
    subgraph Compounding
        D --> E(Sodium Alginate Solution);
        E --> F{Solvent Casting & Drying};
    end
    F --> G[Homogenous Drug-in-SLN Film Sheet];
    G -- Cut to Size --> H(Precise Pediatric Dose);

Section 3: Cross-Domain Applications

Derivative 3.1: AgTech - Foliar Delivery of Systemic Fungicide Prodrug

Enabling Description: A method for delivering a systemic fungicide to agricultural crops. The active fungicide, azoxystrobin, is chemically modified into a di-ester prodrug to enhance its permeability through the waxy leaf cuticle. This prodrug is incorporated into a rapidly dissolving film made of pectin and a surfactant (e.g., Tween 20). The film is applied to the leaf surface. Upon contact with moisture (dew or irrigation), the film dissolves, and the lipophilic prodrug is absorbed by the leaf. Plant-native esterase enzymes cleave the ester bonds, releasing the active azoxystrobin systemically throughout the plant's vascular system for protection against fungal pathogens.

Mermaid Diagram:

sequenceDiagram
    participant A as Film on Leaf
    participant B as Leaf Cuticle
    participant C as Plant Vascular System
    A->>B: Film dissolves with moisture, releases Prodrug
    B->>B: Lipophilic prodrug permeates waxy cuticle
    B->>C: Prodrug enters plant tissue
    C->>C: Plant esterases cleave prodrug
    C->>C: Active Azoxystrobin is released systemically

Derivative 3.2: Aerospace - Zero-G Delivery of Anti-Kinetosis Agent

Enabling Description: A sublingual film for delivering scopolamine to astronauts to counteract space adaptation syndrome. Scopolamine is formulated as a quaternary ammonium prodrug to improve stability and modify its absorption profile. The prodrug is embedded in a fast-dissolving film of pullulan. The film is administered sublingually and dissolves without the need for water, which is a key advantage in a zero-gravity environment. Rapid onset of action is achieved by bypassing first-pass metabolism, allowing for effective management of nausea and disorientation during critical mission phases.

Mermaid Diagram:

stateDiagram-v2
    [*] --> Inactive: Astronaut is asymptomatic
    Inactive --> Active: Onset of Kinetosis Symptoms
    Active --> AdministerFilm: Sublingual Scopolamine Prodrug Film
    AdministerFilm --> Absorption: Rapid dissolution, no water needed
    Absorption --> TherapeuticEffect: Prodrug converts, symptoms abate
    TherapeuticEffect --> Inactive: Return to asymptomatic state

Section 4: Integration with Emerging Technology

Derivative 4.1: AI-Driven Closed-Loop Anaphylaxis Response System

Enabling Description: A closed-loop system for automated anaphylaxis management. The system consists of: (1) a wearable sensor (e.g., a smartwatch with integrated electrochemical sensors) that continuously monitors for biomarkers of anaphylaxis in sweat, such as histamine. (2) A cloud-based AI algorithm that analyzes the sensor data to predict the onset of a systemic allergic reaction. (3) An IoT-enabled dispenser, worn by the user, containing a cartridge of epinephrine prodrug films. Upon positive detection by the AI, the cloud service sends a signal to the dispenser, which automatically dispenses a film into the user's mouth. The event, including sensor data and time of administration, is logged to a secure health record.

Mermaid Diagram:

flowchart TD
    A[Wearable Sensor] -- Histamine Data --> B(Cloud AI Platform);
    B -- Analyzes Risk --> C{Anaphylaxis Predicted?};
    C -- Yes --> D[Signal to IoT Dispenser];
    D --> E(Dispense Epinephrine Prodrug Film);
    E --> F[Patient Administers Film];
    C -- No --> B;
    D -- Log Event --> G[Blockchain Health Record];

Section 5: The "Inverse" or Failure Mode

Derivative 5.1: Biphasic Release Film for Acute and Sustained Action

Enabling Description: A single dosage form designed to prevent biphasic anaphylactic reactions. The film is constructed with two layers. Layer 1 is a rapidly dissolving formulation (using sodium starch glycolate as a superdisintegrant) containing a 0.3 mg equivalent dose of an epinephrine prodrug for immediate treatment. Layer 2 is a mucoadhesive, slow-eroding layer (using Carbopol 971P and HPMC) containing a lower, 0.15 mg equivalent dose of the same prodrug. After the first layer dissolves and provides the initial bolus, the second layer adheres to the buccal mucosa and slowly erodes over 1-2 hours, releasing a sustained, low level of epinephrine to suppress the potential second wave of symptoms.

Mermaid Diagram:

graph TD
    subgraph Time=0-2 min
        A[Layer 1: Rapid Dissolution] --> B(High Plasma Epinephrine);
    end
    subgraph Time=2-120 min
        C[Layer 2: Slow Erosion] --> D(Sustained Low-Level Epinephrine);
    end
    Start --> A;
    A --> C;
    B --> E{Acute Symptom Resolution};
    D --> F{Prevention of Biphasic Reaction};

Section 6: Combination Prior Art with Open-Source Standards

Combination with HL7 FHIR: The AI-driven closed-loop system (Derivative 4.1) will log each automated administration event by creating an MedicationAdministration resource compliant with the HL7 FHIR (v4.0.1) standard. The resource will be populated with a medicationCodeableConcept specifying the epinephrine prodrug, a dosage element detailing the film strength, and an effectiveDateTime timestamp. This resource will be pushed to the patient's designated EHR via a secure API, ensuring interoperability with clinical decision support systems.
Combination with OPC UA: The manufacturing line for the Biphasic Release Film (Derivative 5.1) will be modeled using the OPC UA framework. The dual-layer casting machine's parameters (e.g., Layer 1 pump speed, Layer 2 viscosity, dryer temperature profile) are exposed as OPC UA variables. A Manufacturing Execution System (MES) subscribes to these variables for real-time monitoring and recipe management, and generates an electronic batch record that is compliant with the ISA-88 standard, using OPC UA as the underlying communication protocol.
Combination with W3C Verifiable Credentials: To ensure the authenticity of the Lyophilized Cryo-Stable Film (Derivative 2.1) for institutional buyers like space agencies or militaries, the manufacturer will issue a W3C Verifiable Credential for each batch. This digital credential, signed by the manufacturer's decentralized identifier (DID), will contain claims asserting the batch number, expiration date, and successful completion of stability testing at specified extreme temperatures. This allows a receiving entity to cryptographically verify the product's provenance and quality specifications without relying on a centralized database.