Scale-Up of Liposome Manufacturing
The study provides a comprehensive overview on different stabilization techniques for liposomal formulations. The selection of the appropriate technology for a particular formulation can thereby be based on several considerations. If free flowable particulate bulk material is desired the spraying-technologies are preferred over lyophilization. Another advantage of spraying-based technologies is the possibility to combine the liposome formation step and the drying step within the same process. It is a prerequisite for the selection of the stabilization technique that the integrity of the liposomes is preserved with the incorporated drug after the process. Spray-drying is related to a thermal stress for the formulation but only for a short time. For heat labile drugs processes with low process temperatures, e.g. freeze-drying, spray freeze-drying, inert-spray drying or supercritical drying are most adequate. However, for technologies with a freezing step a sufficient stabilization against freezing induced stress e.g. by the selection of appropriate cryoprotectors is needed.