Viscous Fluid Injection via Droplet Lubrication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The injection of high concentration drug formulations with viscosities ranging from 20 cP to 1000 cP is challenging due to high hydraulic resistance, making conventional delivery methods impractical, and achieving axially lubricated flow is difficult due to eccentricity issues caused by density differences between inner and outer fluids.
Innovation Solution
The system comprises a fluidic pathway with a larger inlet cross-sectional area than outlet, where the second fluid with lower viscosity surrounds the first fluid, maintaining an eccentricity parameter of less than 1, and includes constricted regions and textured surfaces to reduce eccentricity and enhance lubrication, allowing for efficient flow through needles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional delivery methods are used for high concentration drug formulations, then the injection process is simple, but the hydraulic resistance is too high to enable practical injection
Solution Approach 1:
A second fluid with lower viscosity is introduced as an intermediary substance that surrounds the first viscous fluid in a coaxial arrangement. This second fluid acts as a lubricant that reduces the friction between the first fluid and the needle wall, thereby reducing hydraulic resistance and enabling injection of high concentration formulations that would otherwise be too viscous to inject practically.
2Stress or pressure
If axially lubricated flow is attempted with density differences between inner and outer fluids, then viscosity reduction is achieved, but eccentricity causes flow instability
Solution Approach 1:
The system is designed to create a balanced flow configuration where the coaxial arrangement of the two fluids with different densities achieves a stable equilibrium. By maintaining the second fluid surrounding the first fluid in a controlled coaxial manner, the system achieves equipotential flow conditions that prevent eccentricity-driven instability while still benefiting from the viscosity reduction effect of the lubricating outer fluid.
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
This configuration reduces hydraulic resistance, enabling the efficient injection of high concentration drug formulations by maintaining axially lubricated flow and minimizing contact between the first fluid and the needle surface, thus overcoming the limitations of conventional methods.
Implementation Method 1
the second fluid (e.g., a lubricating fluid) lubricates the flow of the first fluid (e.g., a viscous drug) by surrounding the first fluid
Data Source
AI summary
Disclosed herein are articles, systems, and methods for the injection of viscous fluids. For example, inventive articles, systems, and methods for injecting viscous fluids, such as concentrated drug formulations, via droplet lubrication are described.