Binary powder mixtures of four different types of crystalline lactose: alpha-lactose monohydrate, anhydrous alpha-lactose, roller-dried beta-lactose and crystalline beta-lactose, were compressed into tablets. The results showed a proportional intercorrelation of the crushing strength and internal specific surface area of the tablets, respectively, with the composition of the powder blend, when compressed from binary mixtures of same particle size fraction. All data were found to fit the unique relationship between the crushing strength and the internal specific surface area of crystalline lactose tablets. It is concluded that binary mixtures of same particle size fractions of different types of crystalline lactose exhibit no interaction between the components during consolidation