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.
