Antitussive agent and method for making the same

摘要

An antitussive agent. A composition for relieving, preventing and/or treating cough includes a sufficient amount of Cynanchi Atrati Radix extract as an active component. The effective Cynanchi Atrati Radix extract is prepared by extracting Cynanchi Atrati Radix with water, ethanol, hexane, ethyl acetate or a combination thereof. The crude extract can be further fractioned by ultrafiltration or reverse phase column.