Methods: Quantification of VER HCl by ultraviolet absorption spectroscopy and HPLC; evaluate the solubility of VER HCl 120mg sustained-release capsules according to the method in USP 41; evaluate the stability of VER HCl 120mg sustained-release capsules under real condition and accelerated aging condition (temperature 40±1oC, humidity 75%); The evaluation parameters included: pellet appearance, VER HCl content and solubility.