The importance of excipient solubility in wet granulation has been shown using mixtures of lactose and boric acid containing third components of differing solubility characteristics. Sucrose dissolved in the binder solution and increased the amount of liquid available to form liquid bridges between other solid particles and therefore increased the number of solid bridges when the damp mass was dried. Thus, stronger, larger granules were formed. The results obtained with Sta-Rx 1500 and magnesium carbonate powders were also dependent upon the extent of solubility of these powders in the granulating solution.