The method to improve the properties of dry granules was investigated by introducing pre-coating process with an active pharmaceutical ingredient (API) and a submicron-sized binder prior to conventional roller compaction. Hydroxypropylcellulose (HPC) and acetaminophen (APAP) were used as models of a binder and a low-compactible API, respectively. The submicron-sized HPC (HPC-subMP) was obtained by a lab-scale spray dryer. The APAP particles were pre-coated with 5–10% of the HPC-subMP by a high shear mixer, formed into granules using a lab-scale roller compactor, mixed with other excipients and then compressed to make them tablets containing 50% APAP. The tablets prepared with the HPC-subMP showed a high tensile strength without significant retardation of the disintegration time in comparison to those with a raw HPC particle, indicating that the use of API particles pre-coated with submicron-sized binder particles in roller compaction was effective to prepare granules suitable for tableting without any fundamental changes of materials and manufacturing processes.

This paper presents the results of analysis of linear inverse problem for static light scattering (SLS) particle size distribution measurement.

The problem is written by Mv = w, where v is a particle size distribution (unknown), w is intensities of the scattered light of particles (known), and M is a kernel matrix based on Mie scattering theorem.

This study was made to identify characteristics of SLS problem. We made optical simulation of Mie scattering in computer to make kernel matrix. Then we did singular value decomposition to the kernel matrix and evaluated results.

It was found that the singular values has characteristic similar to diffusion equation.

Namely the matrix contains many minute singular values. It shows that SLS is an ill-posed problem which has instability for solution. Also the right singular vectors present TSVD (Truncated singular value decomposition) is not effective.

Finally, we discussed appropriate solution method for SLS.

A population balance equation to predict transient pattern of particle size distribution in a direct granulation of agrochemical suspension using fluidized bed was proposed, in which turbulent correlations on aggregation and additional restriction are considered as coalescence kernel. First of all, transient behavior of particle size distribution at typical operating conditions was numerically investigated. The operation conditions such as spray mist size and slurry flow rate were changed and calculated granule size was compared with measured particle sizes. As a result, it was found that some modification on aggregation kernel must be introduced to obtain reasonable predictions. The granule growth mechanism was thus elucidated by the present model.

A novel type of silicone polymer film prepared from hydrophilic SiO₂ nanoparticles and silicone oligomers having methyl- and methoxy-side groups will be introduced. The typical fabrication process involves the controlled hydrolysis/condensation reaction of silicone oligomers having alkoxy-side chains on hydrophilic SiO₂ nanoparticles, followed by casting and heat treatment to complete polymerization process. A free standing, roll-able, and transparent silicone film possessing a tensile modulus of ca. 7.8 MPa and a strain at the break point of 0.76 % can be successfully manufactured through the proposed process. The relations between the film fabrication process and the macroscopic/microscopic properties of the prepared films will be explained based on the film formation mechanism.

In the car OEM coating, the conventional solvent borne paints have been replaced by water borne paints. In order to utilize water as the paint solvent, there have been several technical problems to be solved. This is because water exhibits much lower vaporization rate, higher surface tension and higher solubility parameter value. In this article, the structure and the coating stages of the ordinary paint layers for car OEM coatings are described firstly. Then the problems and its current technical solutions concerning to utilize water as the paint solvent are described. Due to the much higher heat of vaporization of water, emission of CO₂ from the water borne coating process is larger than conventional solvent borne process. Novel coating process comprising less number of the coating stages are appeared and shown briefly.