A Review on Freeze-drying: A Stability Enhancement Technique

Freeze-drying is effective technique used in pharmaceutical industry to increase the efficacy, shelf-life of formulations and makes easier to transport and storage. Freeze-drying applies to the product that is thermolabile and unstable in solution form, because of utilization of low temperature and pressure. Nowadays freeze-drying gained so much attention in the development of parenteral formulation especially vaccines. The selection of excipients plays a key role in development of freeze-dried product and used to improve the shelf life and makes the product cost effective. The structure of cake not only focuses on appearance of product and also provide information about issues on drying stage that impact quality of product. Tray style freeze dryer helps in development of long-term storage vaccines and labile drugs. It performs freeze drying in containers or in vials on large quantities. This makes tray style freeze dryer become most common for developing lyophilized product. The need for improve the shelf-life of protein-based drug and antibiotics formulations makes tremendous growth of freeze-dried product market. This review focuses on the lyophilization process, design of freeze dryer, role of excipients in lyophilization process, decision of selecting the excipients, importance of cake structure helps to develop stable lyophilized drug product for long-term usage and applications of lyophilization technology.