Method of preparing biologically active formulations

The invention provides pellet for use as a core for a pharmaceutical dosage form having an inner and an outer zone where the inner zone includes a biologically active agent and said outer zone includes a layer formed by applying a substantially dry, free flowing inert powder which forms a non-tacky surface when placed in contact with water. The invention also provides a process for making pharmaceutical pellets where the core or at least one a layer on the core is formed by (a) contacting powder particles, adhering them to each other and compacting the adhered pellets by a rolling movement, wherein the degree of densification is controlled by the rolling movement; and (b) feeding a sufficient amount of a substantially dry, free flowing inert powder which forms a non-tacky surface when placed in contact with water to provide on said particles an outer zone including a layer formed from said substantially dry, free flowing inert powder.