Objective: To optimize ultrafine pulverization process of Codonopsis Radix and investigate its in vitro dissolution. Method: Taking extraction amount of lobetyolin as index,orthogonal test was adopted to optimize ultrafine pulverization process with powder consumption,preliminary powder fineness and pulverization time as factors. HPLC was employed to determine the content of lobetyolin with mobile phase of acetonitrile-water( 20∶ 80) and detection wavelength of 268 nm. Dissolution was determined by Paddle-s...