Freeze Drying Adviser Vol.2

The ‘Freeze Drying Advisor: Illustrated Toolkit for General Users’ from BUCHI provides you with knowledge about hardware, the freeze-drying process, overview of the most important parameters and steps in sample preparation.

Freeze-drying (lyophilisation) is used with many substances and materials, in a wide range of applications such as:

• Removal of water for further processing
• Preservation of a substance characteristics
• Preservation of the initial form
• Conditionment of materials
• Chemical analysis

A typical lyophilisation process comprises three main steps which can take several days to complete – freezing (solidification), primary drying (ice sublimation) and secondary drying (moisture desorption – optional).

The process is known to be rather expensive due to the slow drying rate and the high investment and operating costs. By identifying the critical properties of the formulation, so that the process conditions can be specifically tailored to the formulation characteristics, the freeze- drying cycle can be optimised to use only the required amount of energy and time.

Successful freeze-drying necessitates a good balance of several factors and can be a difficult process to manage. Despite improvements in process knowledge, many misconceptions persist. The aim of this guide is to counteract those misunderstandings through technical notes and answers to frequently asked questions.

The ‘Freeze Drying – Illustrated Toolkit for General Users’ white paper from BUCHI is divided into four main parts.

• Part 1: focuses on the hardware used in freeze drying.
• Part 2: offers an overview of the most important parameters and steps in sample preparation.
• Part 3: concentrates on the freeze-drying process itself by focusing on the most important process parameters.
• Part 4: helps to better understand how to perform freeze drying when solvents other than water are used, either pure or diluted.