A functional study of tubing material for the spray drying of mRNA-lipoplexes

Kiel University, Germany, and  Meggle GmbH & Co. KG present “A functional study of tubing material for the spray drying of mRNA-lipoplexes”:

INTRODUCTION

• The overall aim of this project is the development of an inhalable dry powder platform for mRNA vaccines.
• As many viral infections enter the body through the respiratory tract, an application of mRNA vaccines directly into the lungs might lead to more effective protection.
• Liquid vaccines face the risk of chemical degradation and physical instability, a solid formulation might secure stability without challenging storage conditions.
• DOTAP:DOPE is a safe transfection agent for human administration. and was used as lipoplex builder. The lipoplex composition and transfection efficacy was determined in a previous study.
• In the first spray drying experiments decreased transfection capabilities of the processed mRNA-lipoplexes compared to control were observed.

> We focused on each individual step of the process: pumping, spraying, drying

METHODS AND MATERIALS

1. Preparation of naked mRNA solution with a concentration of 0.002°μg/μl.
2. Preparation of mRNA-lipoplex dispersion:
   a. Formation of DOTAP:DOPE (DD) liposomes via lipid film method and homogenisation with a sonicator
   b. Addition of Firefly Luciferase mRNA in a weight ratio of 5:1 (DD:mRNA)
3. Addition of mannitol as matrix material to a concentration of 20°μg/μl.
4. Pumping and spraying of naked mRNA and lipoplexes, respectively, using 3 tubing materials. Samples were collected with a falcon tube positioned underneath the two-fluid nozzle.
5. Addition of DOTAP:DOPE (DD) liposomes to processed naked mRNA solution in a weight ratio of 5:1 (DD:mRNA).
6. Transfection of mRNA-lipoplexes into CALU-3 cells, measuring of luciferase expression using a luminescence assay. For normalisation to protein content per well, a Bradford-Assay was performed.

RESULTS

1. Spraying and pumping of naked mRNA and Lipoplexes using a silicone tube

2. Pumping of naked mRNA and Lipoplexes using two alternative tubes

CONCLUSION

• Liquid handling and processing complex mRNA-formulations is challenging.
• Adsorption of lipid formulation components to equipment, especially tubing material, can be a major obstacle and has to be avoided.
• In contrast, using the investigated tubing materials adsorption of mRNA itself was not a problem.
• In this study, we identified Tygon® 2375 NSF-51 as a suitable tubing material for the handling of DOTAP:DOPE lipoplexes.

FUTURE WORK

• As a next step, we are going to analyse and optimise the entire spray drying process. In order to spray dry a formulation containing fully functional mRNA-lipoplexes, the addition of stabilising excipients such as leucine, PEG or trehalose, might be necessary.
• Once we have produced a stable formulation, the development of a formulation with suitable aerodynamic characteristics can begin.

Download the full poster “A functional study of tubing material for the spray drying of mRNA-lipoplexes“ here

(or click on the picture below)

Source and authors: Poster “A functional study of tubing material for the spray drying of mRNA-lipoplexes”,
Jana Schembera, Ricarda Leister, Regina Scherließ, Department of Pharmaceutics and Biopharmaceutics, Kiel University, Germany, Meggle GmbH & Co. KG, Wasserburg am Inn, German

See also the overview video of the MEGGLE Dry Powder Inhalation product range here:

Company: MEGGLE is one of the world´s leading manufacturers of pharmaceutical grade lactose and co-processed excipients with expertise of more than 70 years. We encounter lactose in so many areas of our life – reason enough to take a closer look at this multi-functional “white powder”.

Do you need more information or a sample of Meggle excipients?