How can you perform an acid-base titration with antacids if substances, like aluminium hydroxide, are insoluble?

I am trying to perform an experiment in order to determine the efficiency of different antacids. An online search later shows that you add an HCl solution in a solution created with a base/antacid. However, the substances do not dissolve in water and hence precipitate in the bottom. Is there a step I am missing?


