High-pressure treatment, a potential antimicrobial treatment for pharmaceutical preparations? A survey

Sterilization by means of heat, irradiation and gas are methods universally used for the production of microbiologically safe pharmaceutical preparations, medical devices, and foods. However, in many cases limited chemical and physical stability, interaction with the sterilizing agent, and legal restrictions prohibit the use of these methods. About two decades ago high hydrostatic pressure (HHP) treatment was introduced as a commercially attractive alternative sterilizing method for the food industry. HHP is, under appropriate conditions, virucidal, bactericidal, sporicidal, and fungicidal. To achieve a sporicidal effect, the combined action of pressure and heat is necessary. The survival curves of both spores and vegetative cells often exhibit a biphasic or a sigmoid shape. Therefore, the development of reliable sterilization cycles requires detailed studies with individual products. So far the potential application of this relatively new technology has been studied only incidentally for pharmaceutical preparations. In this paper the HHP process, its mode of action, and its kinetics are reviewed. HHP's possible applications for pharmaceutical purposes are discussed.