ABSTRACT
Freeze-drying, or lyophilization, is a critical unit operation in pharmaceutical development and manufacturing because it allows removal of water from heat-sensitive materials at low temperature, thereby avoiding thermal damage caused by more traditional drying operations. Nearly all freeze-dried injectables are aseptically processed where the required volume of liquid is filled into previously washed, sterilized, and depyrogenated glass vials. Special elastomeric closures with slots allowing the escape of water vapor are then partially inserted into the neck of the vials, and the vials are transported from the filling/stoppering line to the freeze dryer. A good general rule in developing a formulation of a freeze-dried pharmaceutical product, or any product for that matter, is to keep the formulation as simple as possible, and to not include any component without a clear rationale for doing so along with supporting data. It is important to have a clear idea of the critical quality attributes of the product before beginning.
