A wide range of new data on recent work with solid and semisolid lipid based depot formulations will be presented. As an alternative to PLGA based implants, lipid based rods for long term delivery of protein drugs have been studied in detail. The depot systems consist only of biocompatible glycerides, mainly triglycerides and are biodegraded by lipases over time. The manufacture of such systems is possible with easy to scale up twin screw extrusion technologies. We now can deliver large molecules like e.g. mabs over more than 6 months in a continuous manner. Comprehensive analytical data on the quality of released proteins are presented as well as data on process engineering and stability of the resulting DDS. 4 marketed antibodies were studied in such lipid based depots and, interestingly, showed very different stability profiles. In a second part, our recent work on lecithin based depots for the delivery range of 2-6 weeks is presented. By using s.c. needle free injection such highly viscous systems can be applied very conveniently and allow the most simple formulation and sustained delivery approach for peptides and other biomolecules. Besides the traditional processing by dual asymmetric centrifugation a novel manufacturing process will be introduced. Recently it became clear, that the ultrafine dispersion of the liposome compartments might not be the most relevant parameter to achieve long term retardation with such systems. We have studied this aspect in more detail and can provide insight into the role protein-lipid interaction, vesicle dispersion and other parameters play.
Audience take away:
• The audience shall understand the options to design depots for biomolecules with simple lipid systems
• The selection of an appropriate design for a certain purpose (a desired release duration) will be explained
• The chances and limits of lipid based depot systems will be critically discussed, also with a side view on competitive approaches
• Overall the state of the art regarding such depots is laid out.