Self-emulsifying pellets in a lab-scale high shear mixer: Formulation and production design

the preparation of solid self-emulsifying drug delivery systems (solid-SEDDS) by means of awet granulation process was optimized in a lab-scale high shear mixer in order to improve the dissolution rate of piroxicam, a poorly water-soluble model drug. With this aim, the classic liquid granulation binder was replaced with an oil-in-water microemulsion, loaded with the drug. The microemulsion formulations were first selected on the basis of phase diagrams and their physicochemical properties, such as viscosity and droplet size. The best microemulsions were then used to prepare solid-SEDDS while maintaining the composition of the solid carrier and the operating conditions of the lab-scale high shear mixer used in this study. These pellets demonstrated an emulsifying capability and their piroxicam release was significantly enhanced with respect to pure drug. Since their dissolution was a function of pellet size fraction, in the subsequent step the yield of the best performing fraction was further increased by modifying experimental conditions for pellet production (impeller speed and amount of povidone). In this way, the 400 μm pellet size fraction of the selected formulation was produced with a percentage yield of 42.5 by wt., with satisfactory technological properties and unchanged drug dissolution performance.