ABSTRACT
OBJECTIVE:To improve the dispersion stability in water of Tussilago farfara powder,and to improve compliance of Xiao’er feike granules. METHODS:The effects of 4 kinds of dispersion stabilizer (sodium hexametaphosphate, dextrin, PEG4000 and lecithin) on dispersion stability of suspension in water were investigated during the grinding of T. farfara using rate of absorbance change(β)and Zeta potential as index;IR spectrum of samples were characterized. Using original formulation with-out dispersion stabilizer as control,the dispersion stability of new formulation granules in water were analyzed comparatively after adding dispersion stabilizer. RESULTS:Among 4 kinds of dispersion stabilizer,β of sample prepared by sodium hexametaphos-phate was the lowest,while Zeta potential of it was the highest;compared with original T. farfara,β of T. farfara grinded with 2.5% sodium hexametaphosphate decreased by 16.8%,and Zeta potential absolute value increased by 29.4%;no new peak was found in IR spectrum. Compared with control granules,granules suspension prepared by new formulation had lower β and higher Zeta potential absolute value (P<0.01);particle size was 30 μm and no large particle aggregation was found;β was less than 5.0% within 20 s sedimentation. CONCLUSIONS:During the preparation of Xiao’er feike granules,the application of sodium hexametaphosphate in the grinding of T. farfara powder can improve the dispersion stability of granules in water and the compliance of the preparation.
ABSTRACT
The formation of bone-like apatite on porous HA/beta-TCP bioceramics in dynamic simulated body fluid (SBF) undergoing a simulated inflammation procedure (pH = 6.5) was investigated in order to study the mechanism of osteoinduction and build a new method to choose biomaterials with better bioactivity. The results showed that the surface of porous HA/beta-TCP bioceramics which underwent a simulated inflammation procedure in dynamic SBF was more smooth. The light acidity in the simulated inflammation procedure would dissolve the fine grains and the parts possessing smaller curvature radius on the surface of porous HA/beta-TCP bioceramics, which would reduce the bioceramics solubility. Followed in normal SBF (pH = 7.4), the amount of bone-like apatite formed on the porous HA/beta-TCP bioceramics was less than that of porous HA/beta-TCP bioceramics incubation in normal SBF all along. The results also showed that the amount of bone-like apatite formed on the porous HA/beta-TCP bioceramics sintered by a microwave plasma was more than that of porous HA/beta-TCP bioceramics sintered by a conventional furnace.