In order to mask the bitter taste of zonisamide, a new antiepileptic compound, nondisintegrating and matrix-types of fine granules were studied by several production methods using ethylcellulose (EC) and hydroxypropylmethyl-cellulose (HPMC) as a coating or as granulating materials.
It was found that the procedure for granulating mixtures of zonisamide, EC, HPMC and lactose with a soluble solvent to EC by using a high speed mixer-granulator is more appropriate to mask the bitter taste of zonisamide than that by the coating method, and it is especially convenient for the mass production.
In this granulating method, the particle size of EC was the most important factor affecting the dissolution rate, the size distribution and the taste of granules.

View full abstract

Scale-up methods and performances of a continuous vibro fluidized-bed were investigated experimentally for the agglomeration of milk powder. Two small-scale and one large-scale experimental apparatus having 0.3, 1.2 and 16.0m² of area of the perforated-plate, respectively, were used in this study.
Agglomerates of similar particle size distributions and moisture contents were produced from these three apparatus by equalizing the following factors: (1) the feed rate of milk powder per unit area of the perforated plate (2) the superficial velocity and the temperature of air (3) the weight ratio of water added to milk powder (4) the size distribution of sprayed droplets (5) the height of the weir placed at the exit and (6) the vibration of the apparatus. The agglomerates had excellent properties for dissolving in water compared with the original milk powder. It was found that the data obtained in this study was useful in the design of commercial plants.

View full abstract

To clarify the fundamental mechanism of shape separation for irregular particles, the relationships between the shape and the friction angle of a particle on an inclined plane were investigated by using typical geometric particles (regular polygon and ellipse) and two kinds of irregular particles. The particle shape was evaluated by a shape index φ (Eq. (23)). The results obtained were as follows:
(1) The theoretical relationships between the rolling friction angle α_cr and φ for regular polygon particles agree approximately with the theoretical ones for ellipse particles.
(2) Experimental relationships α_cr vs. ψ for irregular particles could be estimated by the above theoretical ones.
(3) On the surface of a plate having a larger sliding friction angle α_cs, shape separation might be performed more effectively.
(4) The three dimensional shape of a particle could be closely related to the rolling frictional characteristics.

View full abstract

In order to make certain of the validity of the expression for 50% separation diameter d_c presented in my 2nd report, the theoretical values of d_c were compared with the values of “equilibrium particle size” d_R=E which can be derived from the experimental values of collection efficiency E in 4 similar cyclones for talc powder separation. Similarly, comparison between the theoreticals d_c and the experlmentals d_R=E are also made in the case of quartz dust separation in a cyclone with vortex arrestor in the dust outlet.
It is found that the values of the cut size ratio, d_R=E/d_c, could be expressed as follows:
d_R=E/d_c=K/Re_c^0.1
where K is constant value dependent on introduced cyclone including the effects of agglomeralion, bouncing or re-entrainment of particles upon the overall efficiency: and Re_c is the Reynolds Number based on the cut size particle expressed as
Re_c=d_cw_s/vuk²/gr^k

View full abstract