Using Spray Drying For Flu Vaccines: What Challenges Do We Need To Overcome?
When discussing the challenges of manufacturing flu vaccines, the conversation often shifts toward how manufacturers can meet the global demand each year. Currently there are some very innovative technologies aimed at addressing the challenge of manufacturing a larger supply of flu vaccines in a shorter amount of time, such as Novartis’ use of cell culture and Medicago and Fraunhofer’s use of tobacco plants. However, being able to deliver enough of a vaccine is only half the battle. It also needs to be delivered to its final destination within the appropriate temperature range. “It’s a huge misnomer for people who believe these technologies will unconstraint flu,” says Jim Robinson, VP of global technical operations, biological, and sterile products at Merck, who was involved in the manufacturing of billions of doses of flu vaccine prior to joining Merck. “The product still needs to get into a usable form and be delivered safely to the patient.”
This is the reason Dr. Jeff Breit, director of inhalation and biotherapeutic technologies at Bend Research, a research and development firm for pharmaceutical-delivery technologies that is part of Capsugel’s Dosage Form Solutions business unit, is focusing on how to mitigate the pains of delivering flu vaccines in the cold chain through novel ways of making a solid formulation that doesn’t require temperature control. “If you have a dried product at stable, elevated temperatures, you could actually have delivery to patient populations that don’t have access to cold chain storage,” says Dr. Breit. “If we could actually think about mitigation of cold chain storage, not just in developing nations but also in a place like the United States, spray drying could be an enabling technology from the standpoint of de-risking vaccine delivery to everybody.”
According to Robinson, the future for spray drying in flu vaccine formulation could be bright, if the industry can figure out how to overcome the process’s biggest challenges. “Like the rest of the industry, Merck is often limited in our capacity of freeze drying, so we are always looking for faster and low-cost alternatives to make quality vaccines so they can be available for more global markets,” he says. “Spray drying would be one technology where, if one were able to clear the other manufacturing obstacles, it would fit that purpose.”