What is freeze-drying, advantages, areas where it is used, the principle of freeze-drying, processing method, and why this method to be chosen? (animations are used)

1. PRESENTED BY:
SHIKHANGI SINGh
PHP&FE, GBPUAT,
PANTNAGAR

2. INTRODUCTION
Also known as lyophilisation, lyophilization, or
cryodesiccation
Involves a process of drying in which water is
sublimed from the product after it is frozen.
Standard process used to stabilize, store or
increase the shelf life of drug products and other
biologicals
Products can be stored at room temperature or
4℃ for long time
Typically used to preserve a perishable material
or make the material more convenient for
transport

4. 1 2
The main principle
involved in freeze
drying is a
phenomenon called
sublimation
Principle
The material to be dried is
first frozen and then
subjected under a high
vacuum so that frozen
liquid sublimes leaving
only solid, dried
components of the
original liquid

6. 3
Sublimation of water
can take place at
pressure and
temperature below triple
point

8. • Method of treating the product prior to freezing. Eg. conc. the product,
formulation revision
Pre-treatment
• Cool the material below its triple point.
• Larger crystals are easier to freeze-dry, so slow cooling is preferred
Freezing
• Lowering pf pressure (to the rage of a few millibars)
• Sublimation by supplying heat
• Re-solidification of moisture on Condenser
Primary drying
• Temperature raised to break physico-chemical interactions remove
unfroze water
• Pressure is also lowered
Secondary Drying

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10. WHY THIS
METHOD?
High
stability
(for several
years)
All food
products
can be
dried
Health
friendly
Preservation of
temperature
sensitive
products

11. THANK YOU