This invention relates to a bioactive composition comprising: (d) pH sensitive bioactive agent (e) an edible carboxylic acid containing moiety and (f) an edible alkalising moiety, wherein the proportion of said moieties and active agent provide pH control such that (i) when 400mg of said composition is added to 20 ml of 0.033 normal hydrochloric acid and at a temperature of 37 +/- 3 DEG C, the pH reaches a value in the range 4 to 8, and (ii) when 400mg of said composition is added to 20 ml of deionised water at pH 7 and at a temperature of 37 +/- 3 DEG C, the pH reaches a value less than 8.5.
