The demand for productivity and profitability in the freeze drying, also known as lyophilisation, sector is increasing. This increase is driving practitioners in the industry to consider the benefits of freeze drying compared to spray drying.
Which Should You Choose?
Freeze drying is widely recognised in the biopharmaceutical industry as the preferred method for preserving a wide range of pharmaceutical formulations and biologicals. This drying method is particularly beneficial when stability in the liquid state is inadequate, storage requirements are too stringent, or a solid form of the product is desired to improve shelf life or enable shipping between differing climates and environments.
Freeze drying is certainly the established ‘go to’ drying process across a variety of materials and applications. However, owing to the costs, availability of APIs and sometimes processing and production volumes, evaluation of alternative methods is conducted to ensure that the most suitable drying method for the product and/or project is used. The most popular alternative to freeze drying is spray drying.
Spray drying also offers a variety of benefits. Despite being a comparative newcomer in the industry versus freeze drying, it showcases capabilities to work with higher throughput amounts at a scalable level (continuously rather than batch by batch). As a result, spray drying can also be seen as a viable option for product drying, subject to the contextual processing requirement and product application.
Use in the Industry
Both processes can be used for a vast range of applications. For example, freeze drying is typically sought out for the preservation of different cell types, fine chemicals, laboratory reagents and injectable vaccines, as well as for the food industry & dairy products. Because it is typically performed with product directly filled in vials or other containers, this processing method is best suited for formulations that do not require further processing after drying; additionally, vials can be sealed in-situ of the freeze dryer, thus avoiding potential contamination when the cycle is complete.
Spray drying, on the other hand, is more commonly associated with bulk processing rather than vial based processing. However, it is a common misconception that spray drying is only a suitable process for food and robust bulk pharmaceuticals, where contemporary research suggests it may be a valid methodology for use with some complex products i.e. microencapsulated bacteria and nano particulates, for example.
Both methods of product drying process can be effective when used correctly, and for the appropriate products. In order to achieve optimal results in product processing that includes a drying stage, ultimately the deciding factor for which method will be best for a project, or ongoing processing need, will be the quality of the end product and how it will reach the end users.
Here you can read the Biopharma Group article.