Effervescent couples, histamine H2-antagonist effervescent compositions containing them and their preparation

摘要

The invention relates to an effervescent couple which comprises a mixture of mono-and di-alkali metal citrate as well as to a process for preparing same. The process comprises partially neutralizing citric acid by reacting an alkali metal carbonate or bicarbonate with citric acid and water and controlling the amount of carbon dioxide released during the reaction by stopping the reaction when a certain amount of citric acid has been neutralized. In a preferred embodiment the reaction is stopped when from about 24% to about 54% of the potential amount of carbon dioxide has been released.