Solventless API Coating via Mechanical Film Formation
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Solution Overview
Problem
Current solvent-based coating methods for active pharmaceutical ingredients (APIs) are inefficient, requiring long processing times, generating environmental pollution, and often result in particle breakage or agglomeration, while existing solventless methods struggle to achieve controlled release and taste masking effectively.
Innovation Solution
A solventless process involving mechanical stress to deform a combination of water-soluble and water-insoluble polymer coatings on API particles, creating a continuous film that delays initial release but ensures nearly complete release within 30 minutes, using a combination of water-soluble and swellable materials with substantially water-insoluble polymers, and optionally hydrophobic silica for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If solvent-based coating methods are used, then coating can be applied to API particles, but processing time is long and environmental pollution occurs
Solution Approach 1:
The invention changes the fundamental parameter of the coating medium from solvent-based to water-based, eliminating the need for lengthy solvent evaporation steps. The aqueous suspension coating method allows water to serve as the carrier that can be easily removed, dramatically reducing processing time from hours to minutes while eliminating environmental pollution associated with organic solvents.
Solution Approach 2:
The invention utilizes the phase transition of water from liquid suspension to vapor for coating application and removal. By spraying aqueous suspension and allowing water to evaporate, the coating material is deposited onto API particles without requiring lengthy drying processes, thus reducing processing time while maintaining coating effectiveness.
2Ease of manufacture
If conventional coating methods are used, then coating is applied to API particles, but particle breakage and agglomeration occur
Solution Approach 1:
The invention introduces an intermediary carrier, such as sugar spheres or other inert particles, that mediates the coating process. The API particles are coated indirectly through contact with the carrier particles during tumbling, which prevents direct particle-to-particle impact and reduces breakage and agglomeration while ensuring uniform coating distribution.
Solution Approach 2:
The invention replaces high-shear mechanical mixing systems with low-shear tumbling motion. The coating is applied through gentle tumbling of particles in a coating pan, substituting aggressive mechanical forces with mild gravitational and frictional forces, thereby preventing particle breakage and agglomeration while achieving thorough coating coverage.
3Ease of manufacture
If mechanical coating methods are used, then no plasticizer and thermal treatment are required, but coating layer thickness is limited to 1-5 microns
Solution Approach 1:
The invention employs dynamic control of coating parameters including variable spray rates, adjustable tumbling speed, and controlled suspension concentration. By dynamically adjusting these parameters during the coating process, the method achieves precise control over coating thickness beyond the 1-5 micron limitation of conventional mechanical methods, while maintaining process simplicity without requiring plasticizers or thermal treatment.
Solution Approach 2:
The invention uses periodic intermittent spraying combined with tumbling motion to build up coating layers progressively. The periodic application of coating suspension followed by tumbling and drying cycles allows for controlled accumulation of coating material, enabling precise thickness control and uniform distribution without the limitations of continuous mechanical coating methods.
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 achieves effective taste masking and controlled release of APIs, minimizing particle breakage and agglomeration, with the API being released in a controlled manner, maintaining bioavailability and improving processing efficiency.
Implementation Method 1
a water soluble and/or water swellable coating material
Implementation Method 2
water soluble and/or water swellable coating material
Implementation Method 3
The coated core particles are subjected to mechanical stress to deform the coating on the coated core particles into a substantially continuous or continuous film
Data Source
Figure 1~2A
Figure 2B~3
Figure 4A~4B
AI summary
The present invention is a solventless method of producing polymer coated active pharmaceutical ingredient that is taste-masked and may be released in relatively short time. It employs high energy vibrations or acoustic mixing of API particles, water soluble coating material particles and hydrophobic polymer particles, with or without use of other pharmaceutically relevant powders as media. Additionally the method is capable of producing individually coated drug particles without agglomeration or the long drying times associated with solvent based coating methods.