Fine particle coating by a novel rotating fluidized bed coater

Watano, Satoru; Nakamura, Hideya; Hamada, Kenji; Wakamatsu, Yoshihiro; Tanabe, Yoshiaki; Davé, Rajesh N.; Pfeffer, Robert

doi:10.1016/j.powtec.2003.03.001

Cited by 86 publications

(45 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, fines of isoproterenol HCl (5 wt%) were coated using the hybridizer onto potato starch (∼70 m) followed by a coating of carnauba wax (5 wt%) to produce a controlled-release drug (Ishizaka et al, 1993). Numerous devices have been developed for dry particle coating, which include mechanofusion (Yokoyama et al, 1987), hybridizer (Ishizaka et al, 1993), Magnetically Assisted Impaction Coater (MAIC) (Ramlakhan et al, 2000) and Rotating Fluidized Bed Coater (Watano et al, 1999). In recent years, dry powder coating has widely been used to attach guest particles onto some host particles.…”

Section: Introductionmentioning

confidence: 99%

Improving flowability of cohesive particles by partial coating on the surfaces

Zhou

Zhu

2009

Can J Chem Eng

View full text Add to dashboard Cite

Very fine guest particles were partially coated onto the surfaces of cohesive particles using a patent-pending dry particle coating method involving shear force. It was observed that partial coating on the surfaces could significantly reduce the cohesiveness and hence enhance the flowability of cohesive host particles. Based on different contacting status of the guest particles in relation to the host particles, two contact models were proposed. Inter-particle forces based on these models were employed to discuss the possible roles of the guest particles, partially coated on the host particle surfaces, in reducing the cohesiveness of the host particles.De très fines particules invitées ontété partiellement imprégnées sur les surfaces de particules cohésives au moyen d'une méthode d'imprégnation de particules sèches dont le brevet est en instance et mettant en cause la force de cisaillement. On a observé que l'imprégnation partielle sur les surfaces pouvait réduire considérablement les propriétés de cohésion et, par le fait même, accroître la coulabilité des particules hôtes cohésives. En s'appuyant sur l'état différent de l'entrée en contact des particules invitées, par rapport aux particules hôtes, deux modèles d'entrée en contact ontété proposés. On a employé les forces interparticulaires s'appuyant sur ces modèles pour discuter des rôles possibles des particules invitées, partiellement imprégnées sur les surfaces des particules hôtes, en réduisant les propriétés de cohésion des particules hôtes.

show abstract

Section: Introductionmentioning

confidence: 99%

Improving flowability of cohesive particles by partial coating on the surfaces

Zhou

Zhu

2009

Can J Chem Eng

View full text Add to dashboard Cite

show abstract

“…A good example of surface modification via spray drying is the use of surface-active amino acids, particularly leucine analogs, to reduce surface forces as they are enriched on particle surfaces (2,8,10). Attempts have been made to produce modified surfaces by an encapsulation technique in supercritical carbon dioxide (15) and by spray-coating (14) or by physical vapour deposition, PVD, (3) of particles in fluidized bed reactors.…”

Section: Introductionmentioning

confidence: 99%

A Novel Gas Phase Method for the Combined Synthesis and Coating of Pharmaceutical Particles

2007

View full text Add to dashboard Cite

show abstract

“…Figure 5 shows a schematic diagram of a rotating fluidized bed coater. [2][3][4] A rotating fluidized bed coater consists of a plenum chamber and a porous cylindrical air distributor (ID 0.4 mϫD 0.1 m) made of stainless sintered mesh with 20 mm openings. The horizontal cylinder (air distributor) rotates around its axis of symmetry inside the plenum chamber.…”

Section: Methodsmentioning

confidence: 99%

“…Equation of continuity (1) Equations of motion r-direction (2) q-direction (3) z-direction (4) where, e, u, P are the voidage, the gas velocity, the gas pressure, and r f and f i are the gas density and the volumetric interaction forces between particle and fluid. The f i in Eqs.…”

Section: Numerical Modelmentioning

confidence: 99%

“…[2][3][4] Since the RFB can impart high centrifugal force and drug force to particles, which are larger than the cohesive forces, the RFB enables fine particles to fluidize uniformly. We have already reported that wet granulation 2) and film coating 3,4) of fine particles (group C in the Geldart's classification) could be smoothly conducted in a RFB, in which any conventional fluidization techniques have been impossible to do. However, the particle fluidization behaviors in a RFB are very complicated, and mechanisms of film coating process have not been well studied yet.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Numerical Simulation of Film Coating Process in a Novel Rotating Fluidized Bed

Nakamura

Iwasaki

Watano

2006

CHEMICAL & PHARMACEUTICAL BULLETIN

Self Cite

View full text Add to dashboard Cite

Particle coating process has been widely employed in many industries, such as food, agriculture, cosmetic and pharmaceutical industries, in order to produce functional materials. Among many types of particle coating system, fluidized bed is one of the most promising techniques because of its advantages of high heat transfer, temperature homogeneity, high mixing performance, flowability of particulate materials, and availability of multilayer coating capability.Recently, fine particles, having size range between several micrometers and nanometers, have become major interest in many industries. In the pharmaceutical industry, fine particles have been expected for novel drug delivery systems, such as asthma therapy by inhalation or cancer therapy by transcatheter arterial embolization. However, according to the Geldart's classification, 1) it is very difficult to fluidize fine particles in group C having diameters less than 20 mm, because of the strong cohesive forces between fine particles. Therefore, a reliable technique for fluidization of fine particles and giving tailored functions to them is strongly required. So far, we have developed a novel rotating fluidized bed (RFB) in order to fluidize fine powders. [2][3][4] Since the RFB can impart high centrifugal force and drug force to particles, which are larger than the cohesive forces, the RFB enables fine particles to fluidize uniformly. We have already reported that wet granulation 2) and film coating 3,4) of fine particles (group C in the Geldart's classification) could be smoothly conducted in a RFB, in which any conventional fluidization techniques have been impossible to do. However, the particle fluidization behaviors in a RFB are very complicated, and mechanisms of film coating process have not been well studied yet. From the viewpoint of "Quality by Design (QBD)," it is very important to propose a model for film coating process and analyze the relationship between the operating conditions and quality of products, such as uniformity of coated material, in a RFB.There are some studies on numerical simulation of film coating process in a fluidized bed, such as a population balance model in a conventional fluidized bed 5) and Monte Carlo simulation in a tumbling fluidized bed. 6) However, these models are very complicated and calculation results strongly depend on the model parameters. By contrast, a DEM-CFD coupling model 7) is one of the most useful numerical models of fluidized bed. In this model, individual particle motion and fluid motion are calculated by a discrete element method (DEM) and a numerical method of computational fluid dynamics (CFD). In the DEM simulation, individual particle motion can be calculated based on 'first principle'; integrating the Newton's second law for individual particle, allowing for external forces, such as contact forces, drag force and etc., acting on each particle. Therefore, it is expected that film coating process can be well simulated by using a DEM-CFD coupling model. However, there is no report on numerical sim...

show abstract

Fine particle coating by a novel rotating fluidized bed coater

Cited by 86 publications

References 6 publications

Improving flowability of cohesive particles by partial coating on the surfaces

Improving flowability of cohesive particles by partial coating on the surfaces

A Novel Gas Phase Method for the Combined Synthesis and Coating of Pharmaceutical Particles

Numerical Simulation of Film Coating Process in a Novel Rotating Fluidized Bed

Contact Info

Product

Resources

About