Deliquescence-induced caking in binary powder blends.

In this study, moisture-induced caking of deliquescent crystalline powder blends was investigated. Physical mixtures of sugars and citric acid anhydrous showed significant cake formation when cycled above and below the mixture critical relative humidity. It was found that combinations of glucose and citric acid underwent efflorescence to form crystalline solid bridges while fructose and citric acid cakes contained amorphous material. In conclusion, the reduced deliquescence point in deliquescent solid mixtures was found to cause caking.