Vial Breakage in Lyophilization- Case Studies from Commercial Manufacturing and Laboratory Studies.

Vial breakage during lyophilization reduces yield and can lead to product contamination with glass particulates, personnel interventions during manufacturing and damage to equipment. We present case studies of full-scale commercial lyophilization operations and small-scale laboratory lyophilization studies to understand and mitigate the sources of vial breakage for sterile injectable products. In the first case study, changes to the lyophilization cycle caused the breakage of 11% of the vials.

Modeling the Secondary Drying Stage of Freeze Drying: Development and Validation of an Excel-Based Model.

Although several mathematical models of primary drying have been developed over the years, with significant impact on the efficiency of process design, models of secondary drying have been confined to highly complex models. The simple-to-use Excel-based model developed here is, in essence, a series of steady state calculations of heat and mass transfer in the 2 halves of the dry layer where drying time is divided into a large number of time steps, where in each time step steady state conditions prevail. Water desorption isotherm and mass transfer coefficient data are required.

Systematic investigation of parameters affecting the performance of an agitated filter-dryer.

A systematic experimental investigation of contact drying operation was carried out in an agitated Charles Thompson filter-dryer. In this study, the effect of process parameters (wall temperature, impeller speed, fill level) on the drying performance in the filter-dryer is quantified as a function of bed temperature and solvent concentration. In addition, the impact of drying conditions on the particle size distribution was also examined.

Contact drying: a review of experimental and mechanistic modeling approaches.

Drying is one of the most complex unit operations with simultaneous heat and mass transfer. The contact drying process is also not well understood as several physical phenomena occur concurrently. This paper reviews current experimental and modeling approaches employed towards a better understanding of the contact drying operation.