Inhalable Respirable Aggregates for Sustained Lung Drug Delivery
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Solution Overview
Problem
Conventional methods for delivering poorly water-soluble antifungal drugs to the lungs are inefficient, leading to low bioavailability and poor treatment outcomes for fungal infections, as they fail to achieve sustained lung concentration and residence time, and are associated with systemic side effects and toxicity.
Innovation Solution
The development of inhalable respirable aggregates of poorly water-soluble active agents, formed through methods such as spray freezing into liquid, evaporative precipitation into an aqueous solution, and controlled precipitation, which achieve a maximum lung concentration of at least 0.5 μg/g and maintain it for at least 2 hours, avoiding systemic side effects and enhancing bioavailability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional techniques are used for delivery of agents to the lung, then the delivery process is simple, but only about 10 to 20% of the agent reaches the lung due to losses to the device, mouth and throat, and exhalation
Solution Approach 1:
The patent changes the particle size parameter to submicron range (0.5-5 μm) and controls particle morphology to achieve deep lung penetration. This parameter optimization resolves the contradiction by enabling particles to bypass upper respiratory tract deposition and reach the deep lung efficiently, thereby increasing the quantity of therapeutic agent that reaches the target site while minimizing losses.
2Quantity of substance
If particles are made small enough to reach deep lung, then delivery efficiency improves, but particles must also be able to release their content to be effective
Solution Approach 1:
The patent creates particles with heterogeneous internal structure where the core contains the therapeutic agent and the shell or surface contains porosity features. This local quality differentiation allows the particle to maintain structural integrity for deep lung delivery while providing localized release pathways at the particle surface, thereby simultaneously achieving deep lung penetration and effective drug release.
Solution Approach 2:
The patent incorporates porous structures within the particle matrix to facilitate drug release. The porosity provides channels for therapeutic agent diffusion from the particle interior to the external environment, resolving the contradiction between maintaining small particle size for deep lung delivery and ensuring effective drug release at the target site.
3Manufacturing precision
If mechanical micronization methods are used, then particle size can be reduced, but friction generated during milling may lead to thermal or mechanical degradation of the active agent
Solution Approach 1:
The patent replaces mechanical milling processes with non-mechanical particle formation methods such as spray drying, precipitation, or emulsion techniques. These alternative methods achieve the desired submicron particle size without generating friction-induced heat or mechanical stress, thereby preventing thermal or mechanical degradation of the active agent while still achieving precise particle size control.
4Ease of manufacture
If spray drying is used to micronize drug substances, then particles can be formed, but there is difficulty with capturing the particles when they are relatively small
Solution Approach 1:
The patent forms composite particles by incorporating the therapeutic agent with carrier materials or excipients that provide structural support and improve particle handling characteristics. This composite approach maintains the small size needed for deep lung delivery while enhancing particle stability and capture efficiency during manufacturing processes like spray drying, thereby resolving the contradiction between particle size and capture capability.
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 approach significantly enhances the bioavailability of antifungal agents, achieving effective treatment of fungal infections by maintaining high lung concentrations and reducing systemic side effects, thereby improving treatment outcomes and safety.
Implementation Method 1
spray freezing into liquid
Implementation Method 2
evaporative precipitation into an aqueous solution
Data Source
AI summary
Inhalable compositions are described. The inhalable compositions comprise one or more respirable aggregates, the respirable aggregates comprising one or more poorly water soluble active agents, wherein at least one of the active agents reaches a maximum lung concentration (Cmax) of at least about 0.25 μg/gram of lung tissue and remains at such concentration for a period of at least one hour after being delivered to the lung. Methods for making such compositions and methods for using such compositions are also disclosed.