pMDI Formulation with HCl and EDTANa4 for LABA Stability

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Solution Overview

Problem

Existing pressurized metered dose inhaler (pMDI) formulations with LABA agents and corticosteroids face stability issues over extended periods, particularly when contained in aluminum cans, necessitating improved chemical stability to maintain consistent active ingredient delivery.

Innovation Solution

Incorporating a mixture of an acid, such as hydrochloric acid (HCl), and a chelating agent, like EDTANa4, into the formulation with a LABA agent and optionally a corticosteroid, stabilizes the formulation, enhancing its stability even in aluminum cans.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a LABA agent and corticosteroid are formulated in a pMDI device with aluminum canister, then the formulation can be administered effectively, but the chemical stability of active ingredients deteriorates over extended periods

Engineering Contradiction:
Improvechemical stability of active ingredientsVSAvoidproduct lifetime
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

A chelating agent is introduced as an intermediary substance that binds to metal ions (Al³⁺ from the aluminum canister) to form stable complexes, preventing these metal ions from catalyzing the degradation of LABA agents and corticosteroids. This mediator approach effectively isolates the harmful interaction between the aluminum canister and the active ingredients, maintaining formulation stability throughout the product lifetime.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the chemical environment of the formulation by adjusting pH levels and adding stabilizing agents, thereby changing the parameters that govern chemical reactivity. By controlling the pH and introducing chelating agents, the formulation's resistance to degradation is enhanced, allowing stable storage in aluminum canisters over extended periods without significant loss of active ingredient integrity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If stabilizing agents are added to improve chemical stability, then active ingredient degradation is reduced, but the formulation complexity increases

Engineering Contradiction:
Improveformulation stabilityVSAvoidformulation composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and addresses the specific destabilizing factor (metal ion catalysis) by selectively adding only the necessary chelating agent to bind these ions. Rather than adding multiple broad-spectrum stabilizers that would significantly complicate the formulation, the solution targets the specific mechanism of degradation, minimizing the increase in formulation complexity while achieving the desired stability improvement.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If the formulation is stored in an aluminum canister for extended periods, then manufacturing and device simplicity is maintained, but degradation products increase

Engineering Contradiction:
Improvecanister manufacturing simplicityVSAvoiddegradation products
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potentially harmful interaction between aluminum canister material and active ingredients into a beneficial outcome by adding a chelating agent that selectively binds to aluminum ions. This approach allows the continued use of simple, inexpensive aluminum canisters while preventing them from generating degradation products, effectively transforming the canister from a source of instability into a stable delivery system.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The inclusion of a mixture of HCl and EDTANa4 significantly improves the stability of LABA agents and corticosteroids in pMDI formulations, maintaining high residual active ingredient levels and ensuring consistent delivery over time.

Implementation Method 1

the inclusion of a mixture of an acid and a chelating agent in a formulation comprising a LABA agent, optionally in combination with a corticosteroids, substantially avoids the degradation of said active ingredients

Methodology Applied
Scientific EffectChelation:

Implementation Method 2

a pharmaceutical composition comprising formoterol fumarate in a solution of HFA propellant and a co-solvent, containing an amount of HCl such that the solution has an apparent pH between 3 and 3.5

Methodology Applied
Scientific EffectpH control:

Data Source

PatentUS20250312274A1A pharmaceutical formulation for pressurised metered dose inhaler
Publication Date: 2025.10.09 CHIESI FARMACEUTICI SPA

AI summary

The present invention generally relates to pharmaceutical composition comprising a LABA agent, optionally in combination with other active ingredients, a mixture of an acid and a chelating agent, a propellant and a co-solvent. The invention also provides a pharmaceutical composition for the treatment of respiratory diseases, such as asthma and COPD.