Spray-Drying Process Using Flash Nozzle Cavitation
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Solution Overview
Problem
Conventional spray-drying processes are limited by low solubility of active agents and matrix materials at room temperature, leading to low throughput, non-homogeneous products, and broad particle size ranges due to the avoidance of elevated temperatures for safety and thermal stability concerns.
Innovation Solution
A spray-drying process that increases the temperature of the feed suspension above the ambient-pressure boiling point of the organic solvent, using a flash nozzle to induce cavitation and a sweep gas to prevent solids buildup, allowing for higher concentration of active agent and matrix material in the spray solution, resulting in more uniform and homogeneous products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If elevated temperatures are used to increase solubility of active agent and matrix material, then throughput is improved, but safety risks increase due to flammability of organic solvents
Solution Approach 1:
The patent replaces flammable organic solvents with water as the solvent medium, creating an inherently safer processing environment. Water does not present flammability risks even at elevated temperatures, allowing the process to operate at higher temperatures (above 100°C) to increase solubility and throughput without compromising safety. This fundamental solvent substitution eliminates the harmful factor while preserving the beneficial effect.
2Productivity
If elevated temperatures are used to increase solubility, then throughput is improved, but thermal degradation of active agent and matrix material occurs
Solution Approach 1:
The patent changes the fundamental parameter of solvent type from organic to aqueous, which alters the temperature-stability relationship. Many active agents and matrix materials exhibit different thermal stability profiles in aqueous versus organic environments. The water-based system allows for elevated processing temperatures that achieve high solubility and throughput while the specific combination of aqueous solvent and selected materials maintains compositional stability, avoiding thermal degradation.
3Reliability
If room temperature spray-drying is used to maintain safety and stability, then solubility is limited, but product homogeneity is poor
Solution Approach 1:
The patent raises the processing temperature parameter from room temperature to elevated temperatures (above 100°C) in an aqueous system. This temperature increase dramatically improves the solubility of active agents and matrix materials, enabling formation of homogeneous saturated solutions prior to spray-drying. The enhanced solubility ensures uniform distribution of components, leading to homogeneous spray-dried products while maintaining safety through use of water instead of organic solvents.
4Reliability
If room temperature spray-drying is used, then safety is maintained, but particle size distribution is broad
Solution Approach 1:
The patent implements elevated temperature processing (above 100°C) in an aqueous system, which fundamentally improves solution homogeneity before atomization. The high temperature ensures complete dissolution and uniform distribution of all components at molecular level. When this homogeneous saturated solution is rapidly cooled and spray-dried, it produces narrow particle size distributions because the starting solution is truly homogeneous, unlike room temperature processes that work with incomplete dissolution.
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 process increases throughput, produces more uniform particle sizes, and reduces manufacturing costs by achieving higher solubility and faster evaporation, leading to improved atomization and solidification times.
Implementation Method 1
temperature T2 of the feed suspension after being delivered to a heat exchanger, is greater than the ambient-pressure boiling point of the organic solvent
Implementation Method 2
A flash nozzle utilizes a pressure drop that induces cavitation in the spray solution prior to exiting the nozzle orifice to induce droplet formation
Implementation Method 3
A flash nozzle utilizes a pressure drop that induces cavitation in the spray solution
Implementation Method 4
the disclosed processes result in rapid evaporation of the organic solvent, and shorter times to solidification than conventional processes
Data Source
Figure 1~2
Figure 3
AI summary
The process comprises delivering a spray solution comprising an active agent and a matrix material in an organic solvent to a spray-drying apparatus, atomizing the spray solution into droplets within the spray-drying apparatus to remove at least a portion of the organic solvent from the droplets to form a plurality of particles, and collecting the particles. The spray solution may be formed by forming a feed suspension comprising the active agent, the matrix material, and the organic solvent, wherein the feed suspension is at a temperature T1, and directing the feed suspension to a heat exchanger, thereby increasing the temperature of the feed suspension to a temperature T2, wherein T2 is greater than T1, and the spray solution is at a pressure greater than the vapor pressure of the organic solvent at T2, such that the active agent and matrix material are soluble in the organic solvent at T2.