Physicochemical comparison between microcrystalline cellulose and silicified microcrystalline cellulose

Silicified microcrystalline cellulose (SMCC) has been compared with a standard grade of microcrystalline cellulose (MCC) using several physicochemical techniques in order to elucidate any chemical or polymorphic changes in the material that could be attributed to the silicification process. Samples of SMCC, MCC and dry and wet mixes of MCC and silicon dioxide were analysed using FT-IR, C-13 NMR, powder X-ray diffraction, mercury porosimetry, helium pyonometry and scanning electron microscopy together with particle size analysis and deaggregation studies. Analysis of the data obtained from these methods suggested that there were no discernible chemical or polymorphic differences between the samples, indicating that the 'silicification' process produces a material which is chemically and physically very similar to standard MCC. (C) 1998 Elsevier Science B.V. All rights reserved.