effervescent salt

ef·fer·ves·cent salt

Any of the preparations made by adding sodium bicarbonate and tartaric and citric acids to a medicinally active salt.
References in periodicals archive ?
Some people find effervescent salts, such as liver salts, help," says Angela Chalmers, Boots pharmacist.
Peppermint Foot Soak (pounds 7) is a revitalising treat, containing effervescent salts to cool cleanse and refresh.