Application of calcium silicate for medicinal preparation. I. Solid preparation adsorbing an oily medicine to calcium silicate.

Calcium silicate (Florite RE, FLR), a fine porous powder, was recently approved as a medicinal additive. In this study we sought to make a solid preparation by absorbing an oily medicine to FLR; tocopheryl nicotinate (TN) was used as the oily medicine. TN adsorbed to FLR powder (TN-PO) was prepared by adsorbing TN ethanol solution to FLR and granulating with hydroxypropylcellulose (HPC) in order to improve the flowability. The results were as follows. FLR showed an excellent liquid holding ability compared with other excipients, and this was attributed to the high capillarity of the pores. In the adsorbing process, FLR particles were granulated with TN overflowing from the pores or adhering to the particle surface. The angle of repose was decreased with increasing TN content, which was attributed to the process of granulation, and the angle of repose of the granules with a binder (TN-GR) was below 40 degrees at any TN content. These results show that FLR is an useful additive for the solid preparation of an oily medicine.