Study on Effect of Excipient and Particle Size on Hygroscopicity of Astragali Radix Extract

OBJECTIVE To investigate the effect of excipient and particle size on hygroscopicity of Astragali Radix extract.METHODS Astragali Radix extracts were prepared into size of 50-65 mesh, 65-80 mesh, 80-100 mesh, 100-120 mesh, 120-150 mesh; moisture adsorption kinetics and critical relative humidity were constructed for the above extracts. The effect of the kind and amount of the excipient on hygroscopicity of extract was studied.RESULTS The particle size of the extract and the kind of the excipient had an obvious effect on hygroscopicity.CONCLUSION The bigger the particle size is, then the larger the critical relative humidity is, the worse the hygroscopicity is. Astragali Radix extract is mixed with 16 excipients and lactose is of the best moistureproof effect.