ABSTRACT

Dry heat is one of the oldest methods of sterilization. Dry heat is used in the pharmaceutical industry mainly for depyrogenation of glassware and equipment going into an aseptic processing area. Due to the high heat input required for the depyrogenation process, products that have been validated for depyrogenation are considered to be validated for sterilization without additional work. One of the most effective ways to inactivate bacterial endotoxin—to depyrogenate—is by a dry-heat process. This occurs basically through an incineration process. The materials being treated must be heat stable due to the high temperatures required for an effective process. Dry heat is not widely used as a mode of sterilization due to the inefficiency of the process. The issue is that air is a good insulator with heat transfer from air to product items in dry heat being slow. The heat conductivity of the items themselves can be somewhat slow, and stratification of air in the chamber can occur.