Novel Technique for Coating of Fine Particles Using Fluidized Bed and Aerosol Atomizer

Abstract

Fine particles are widely used in many industrial fields, and there are many techniques applied for these particles, like electroplating, and chemical and physical vapor deposition. However, in the food and pharmaceutical industries, most coating processes conducted with fluidized bed use core particles with a diameter larger than 200 μm, otherwise agglomerates are formed. This study contributes to the development of a new coating process for fine particles with diameters of around 50 μm. The innovation lies in the combined use of a Wurster fluidized bed and a novel aerosol atomizer. The feasibility of the operation is based on the application of the aerosol atomizer, which generates droplets smaller than 1 μm in diameter. A series of experiments with different coating solutions and glass beads in a 150 mm fluidized bed fed with droplet aerosol supplied from the cone chamber bottom is presented. The quality of the coating product is analyzed by scanning electron microscopy and CAMSIZER®. In this way, the influence of different conditions and core material properties on the product quality were determined. Experimental results showed the coating layer quality getting worse as coating solution viscosity became lower, meanwhile moderate process temperature was found to enhance coating layer formation and quality of that. It was also observed that lower aerosol feed rates help improve the yield of the process.

Specialised Coating Processes Finding Pharmaceutical Applicability

“…However there may slight variations in process depending on nature of substrate, apparatus, processing conditions, and CM(s) used 4,9 . Available WCMs are pan coating, fluidised bed coating, wet-chemistry based techniques (coacervation, urea/formaldehyde deposition, interfacial polymerisation, and many others) 1,[5][6][7]9 .…”

“…In this area, pharmaceutical technocrats and researchers are working extensively 1,3 . They are mostly engaged in modifying SDFSP's interaction behaviour and/or finding their worthy applications and functionalities; for taking assorted advantage 1,3,5 . In this regards, they are exploiting numerous elegant strategies/ engineering methods to modify SDFSP's surface and/or surface attributes [1][2][3] .…”

Development of a Semi-Empirical Model for Droplet Size Determination of a Three-Channel Spray Nozzle for Pellet Coating Based on the Optical Method Concept

“…Therefore, alongside the basic model properties presented in the Supplementary Section S1, the final equations for the average and the standard deviation of droplet size were extracted from MODDE software by scaling and centering the responses included as significant in the models constructed (Table 4): The scale-up of the fluid bed coating process is simplified because the distribution of droplet size can be kept constant when transferring from laboratory to production scale, thereby eliminating one of the various influences on the overall fluid bed coating process. First, using Equation (11), by inputting the dispersion properties and process parameters used on the laboratory scale, the average droplet size on the laboratory scale is determined. Second, a similar procedure is repeated with Equation (12), where the standard deviation is calculated.…”

“…Pellet coating is generally considered a critical process step, and it could have a significant influence on CQAs, such as drug dissolution (semi-permeable membrane or enteric coatings), stability of the product (coating with moisture-protective polymers), or even assay and content uniformity, when coating with an active pharmaceutical ingredient (API; i.e., layering) [6][7][8][9]. Furthermore, a coating can be used to mask an unpleasant or bitter taste and therefore improve patient compliance [6][7][8][9][10][11].…”

Thermo-Mechanical Dry Coating as Dry Coating Process is for Pharmaceuticals

“…High surface area of FiUlFiPs is reasoning for receiving interest 1,2,4 . Researchers (scientists and engineers) in pharmaceutical sectors working extensively in finding applications and taking advantage of many worthy properties and new functionalities attributed to FiUlFiPs, as drug delivery system/carriers 1,2,5 . They were exploiting numerous elegant strategies of particle engineering methods to modify density and/or shape of FiUlFiPs to resolve the problems caused by cohesion and find their worthy properties and new functionalities [1][2][3] .…”