Pharmaceutical Freeze Drying
Freeze drying technology has now become a standard practice in many pharmaceutical manufacturers. It gently dries products without ruin their chemical and physical properties.
Freeze drying also called lyophilization, is a low temperature dehydration process that used to treat heat sensitive products. The technology has now become a standard practice in many pharmaceutical manufacturers. Because it gently dries products without ruin their chemical and physical properties.
As per related articles published, in 2016, more than 50% of approved biopharmaceutical drugs are require freeze drying in manufacturing process. And the rate is increasing year by year. Which means lyophilization plays an important role in biopharma industry.
Freeze-drying was invented by Jacques-Arsene d’Arsonval at the College de France in Paris in 1906. Later, during World War II, it was widely implemented to preserve blood serum. Since then freeze-drying has become one of the most important processes for preservation of heat-sensitive pharmaceuticals and biological materials.
1, Preserve chemical and physical properties
- Unlike heat-based drying methods, freeze drying uses low temperatures and processes called sublimation and desorption to vaporize water. It avoids too much heat to protect product integrity, this doesn’t affect chemical or physical properties.
2, Preserve biological activity
- For the pharmaceuticals industry, where many products and specimens are delicate, unstable and heat-sensitive, this preservation technique is ideal. Typically freeze drying ensures biological activity >90%.
3, Easy to store and transport
- Freeze dried pharmaceuticals moisture contain <3%, which means they are suitable for storage and transport at room temperature for long periods of time. Adding water is all that’s needed to reconstitute the product. The capacity to stabilize products and increase the shelf life of drugs and medications makes freeze drying one of the most widely used techniques in the pharmaceutical industry. It is said that freeze dried pharmacy can last at least 5 years and up to 30 years.
Pharmaceutical Freeze Drying Process
Essentially, freeze drying pharmaceutical consists of three main steps: freezing, primary drying and secondary drying, which includes:
Freezing: The aqueous product undergoes freezing and this is done quickly to prevent large crystals from forming that might rupture the cell walls of the material.
Primary Drying (Sublimation): This is the second phase of the freeze drying process in which pressure is reduced and heat is applied to vaporize the frozen water. This process takes hours to several days to complete depending on the sample. Once primary drying is complete, 93-95% of the water has already been sublimated out.
Secondary Drying (Adsorption): This is the final phase in which temperature is increased even further to remove residual moisture. The remaining water trapped in the solid matrix is desorbed by means of an increase in the temperature.
Freeze-dried pharmaceuticals are then packaged in glass vials with rubber stoppers and aluminum crimping caps.
Pharmaceuticals Suitable for Freeze Drying
Examples of freeze-dried pharmaceutical products are:
- Red blood cells
- Vitamins and minerals
- Collagen peptides
- Active pharmaceutical ingredients