A functional study of tubing material for the spray drying of mRNA-lipoplexes
Jana Schembera1, Ricarda Leister2 and Regina Scherließ1
1Department of Pharmaceutics and Biopharmaceutics, Kiel University, Grasweg 9a, Kiel, 24118, Germany
2Meggle GmbH & Co. KG, Megglestr. 6-12, Wasserburg am Inn, 83512, Germany
Summary
The overall goal of this project was to produce an inhalable dry powder platform for mRNA vaccination. In order to achieve this goal mRNA-lipoplexes comprising mRNA and DOTAP:DOPE were developed, which shall be transferred to inhalable dry particles by spray drying. Compatibility experiments with mRNA-lipoplexes have shown that mannitol or lactose could be suitable excipients with established use in inhalation. However, the first spray drying experiments revealed decreased transfection capabilities of the processed mRNA-lipoplexes compared to the control. Thus, we focused on the spraying process itself to assess the influence of each individual step: the pumping of feed liquid through the tube, the atomisation and the drying itself. The tube was identified as a major obstacle as the lipoplexes adsorbed to the tubing, resulting in loss-of-function of the mRNA-lipoplexes. Comparative studies identified materials suitable for the processing of DOTAP:DOPE mRNA-lipoplexes.
Key Message
Liquid handling of mRNA-lipoplex formulations is not as mundane as it seems. Commonly used silicone tubes are not suitable as lipoplexes adsorb to the inner surface. In this study, the Tygon® 2375 NSF-51 tube showed the lowest impact on the transfection efficiency of mRNA-lipoplexes.