Influence of manufacturing process on tabletting ability of powder: comparison between blending, grinding, and spray drying of two formulations made of theophylline and lactose/cellulose or Cellactose.

Three manufacturing processes were applied to two formulations composed of 20% anhydrous theophylline associated with either 20% microcrystalline cellulose and 60% lactose or 80% Cellactose. The processing method (dry blending, grinding, or spray drying) and the formulation were investigated through the comparison of the physical and flow characteristics and the compactibility of the end products. The results demonstrated that the formulation had a major effect on the mechanical properties, with binary blends exhibiting a higher resistance than ternary ones, whereas flow properties and densification depended on the process. Nevertheless, it was also observed that spray drying decreased the difference between the mechanical properties of the two formulations, probably by modifying the texture of the Cellactose in suspension.