Manufactured by SANATOGEN COMPANY (CHINA), THE.

"Sanatogen" appeared first in the Shenbao (1914), then in the North China Daily News (1924). This tonic was introduced  by a German company (BAUER CHEMICAL COMPANY) in 1898. Since the First World War, foreigners boycotted the German product and the British company "Sanatogen Company" launched a competitive brand as a substitute to replace the German brand.

Source: Wikipedia (https://en.wikipedia.org/wiki/Sanatogen).