Metal Oxide Coating for Particle Leaching and Release Control
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Solution Overview
Problem
Existing methods for coating solid, water-insoluble particulate matter with metal oxides lack the ability to control and tune the thickness of the metal oxide layer effectively, leading to issues with active agent leaching and toxicity, especially in dermatological and agricultural applications.
Innovation Solution
A process involving multiple iterations of coating solid, water-insoluble particulate matter with a metal oxide layer using ionic additives, followed by aging, to achieve a dense and controllable metal oxide coating that reduces active agent leaching and enhances release control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional coating methods are used to coat solid water-insoluble particulate matter with metal oxides, then the coating process is simple, but the thickness of the metal oxide layer cannot be controlled and tuned effectively
Solution Approach 1:
The coating process is divided into multiple sequential coating steps, where a thin metal oxide layer is deposited in each step and then aged before the next coating step. This segmentation allows precise control over the final thickness by adjusting the number of coating cycles, with each cycle contributing a controlled amount to the total thickness.
Solution Approach 2:
The coating process employs periodic repetition of coating and aging steps. Each coating step is followed by an aging period where the layer consolidates and stabilizes, then another coating step is applied. This periodic action enables progressive thickness buildup with control at each stage.
2Object-affected harmful factors
If the metal oxide layer is made thick to reduce active agent leaching, then toxicity and side effects are reduced, but the release control capability is compromised
Solution Approach 1:
The aging time parameter is used to control the properties of the metal oxide layer. By adjusting the aging time between coating steps, the layer's density, porosity, and crystallinity are modified, which in turn controls the release rate of the active agent. This allows optimization of both protection against leaching and controlled release duration.
Solution Approach 2:
The coating structure is designed to be dynamic rather than static - the aging process continuously modifies the layer's properties to optimize release characteristics. The layer evolves from an initial less dense state to a more dense, controlled state through aging, enabling tunable release behavior.
3Manufacturing precision
If multiple coating steps are performed to achieve controllable thickness, then the metal oxide layer thickness can be tuned, but the manufacturing time increases
Solution Approach 1:
The aging step is performed as a preliminary action between coating cycles, allowing the layer to pre-consolidate and stabilize before the next coating step. This preliminary aging prevents defects in subsequent layers and reduces the need for additional corrective steps, actually improving overall process efficiency despite the added time.
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 process results in a thick, dense metal oxide layer that effectively isolates active agents, reducing side effects and allowing controlled release, suitable for dermatological and agricultural uses.
Implementation Method 1
contacting the solid, water-insoluble particulate matter with an ionic additive and an aqueous medium to obtain a dispersion of said particulate matter having positive charges on its surface
Implementation Method 2
coating the particulate matter by precipitation of a metal oxide salt
Implementation Method 3
aging the coating layer
Data Source
AI summary
The invention relates to a process for coating a solid, water-insoluble particulate matter, with a metal oxide comprising: (a) contacting the solid, water-insoluble particulate matter with an ionic additive and an aqueous medium to obtain a dispersion of said particulate matter having positive charges on its surface; (b) subjecting the particulate matter to a coating procedure comprising precipitating a metal oxide salt onto the surface of the particulate matter to form a metal oxide layer thereon to thereby obtain particulate matter coated by a metal oxide coating layer; (c) repeating step (b) at least 4 more times; and (d) aging said coating layer. The invention further relates to particles comprising a particulate matter coated by a metal oxide layer, to a use of the particles for topical administration, and to a method for preventing, reducing, or eliminating pests at a locus, using the particles.