With reference to which classification has the statement “ranitidine is an antacid” been given?

This statement refers to the classification of drugs according to pharmacological effects of the drug because any drug which is used to neutralise the excess acid present in the stomach will be called an antacid and ranitidine prevents the interaction of histamine with the receptors presents in the Stomach wall. Histamine stimulates the secretion of pepsin and HCl in the stomach.