StarLac® is a new direct compression excipient, produced by spray-drying of α lactose-monohydrate and maize starch. Powder properties like densities and particle size distribution are useful to characterize the flowability of materials. Pressure-time-profiles, pressure-porosity- profiles and compactibility plots help to evaluate the tableting properties.

Aim of this study is to characterize both the pure substances and the physical mixtures of spray-dried lactose and maize starch in comparison to the new direct compression excipient StarLac®. Flowability and tableting properties indicate that StarLac® is a useful new excipient for direct compression. Among its main advantages are: a higher plastic deformability, and a better compactibility and flowability.