Alternative methods of controlling nucleation in freeze drying

The control of freezing, and particularly of the nucleation temperature, is one of the most challenging aspects of the development of a lyophilization cycle. Technological advances of recent years have increased the efficiency with which nucleation temperature can be adjusted. This chapter discusses these technologies, as well as some emerging technologies that might play an important role in near future. In particular each technology is presented in terms of easy to be implemented, scalability on industrial units, influence on product morphology, protein preservation, intra-vial and vial-to-vial heterogeneity, and process performance.