Reduction of tablet coloration at tableting for oily medicine (tocopheryl nicotinate)

The powder (TN-PO) which adsorbed D,L-tocopheryl nicotinate (TN) as an oily medicine was prepared using porous calcium silicate (Florite(R)RE, FLR) as an adsorbing carrier. Tablets (TN-TAB) were produced by compression of TN-PO at different compression pressures. As TN-PO was compressed at the higher TN content in TN-PO and compression pressure, the more TN was exuded from TN-PO, and an increase in the degree of tablet coloration was observed. Therefore, FLR or colloidal silica (AEROSIL(R)200, AER) was newly added to TN-PO at compression to reduce the degree of tablet coloration. Further, the effects of addition of FLR or AER on the crushing strength, friability, porosity and disintegration property of the tablet and the dissolution property of TN from the tablet were studied. After addition of FLR or AER, a similar reduction of tablet coloration was observed. When the addition percentage of FLR to TN-PO exceeded 30%, the crushing strength of the tablet increased significantly. On the other hand, when TN-PO added with AER was compressed, no change was observed in the crushing strength of the tablet. The disintegration time of the tablet with added FLR was shorter than that of the tablet with added AER. At every addition percentage studied, the tablet with added FLR showed a higher releasing ability of TN compared with the tablet with added AER. These results indicate that it is possible to reduce tablet coloration by adding FLR or AER at compression of TN-PO. Further, it is considered that the differences in the crushing strength, disintegration property and dissolution property of TN between the tablets with added FLR or AER resulted in different liquid adsorbing and holding mechanisms of FLR particles and AER particles.