Milling of Organic Solids

Despite considerable efforts that have been made in the past with regards to milling, no single model has the capability to predict the milling behaviour of materials. The objective here is to further understand the role of material properties in breakage, under the influence of temperature. The methodology is to characterise the mechanical properties of materials at the single particle level using quasi-static nano-indentation and dynamic impact tests. The effect of temperature on the breakage behaviour of these materials is investigated under dynamic impact conditions and the effect of temperature on mechanical properties indirectly inferred. Furthermore, dynamic impact breakage is compared to bulk milling behaviour, under the influence of temperature. A widely used pharmaceutical active ingredient, Aspirin, and two excipients sucrose and -lactose monohydrate (-lm) are chosen as model materials. All three are regarded as semi-brittle materials with different mechanical properties.