Abstract

LYOPHILIZATION / FREEZE DRYING – A REVIEW

Kunal A. Gaidhani*, Mallinath Harwalkar, Deepak Bhambere, Pallavi S. Nirgude

Abstract

Freeze-drying is a method of removing water by sublimation of ice crystals from frozen material. Suitable parameters of process application allow us to obtain best quality products compared to products dried with traditional methods. In pharmaceutical field lyophilization has become important subject to ongoing development and its expansion. Lyophilization is common, but cost intensive and hence one of the key objectives during freeze-drying process development is to minimize the drying time (mainly primary drying time, which is the longest of the three steps in freeze-drying). However, increasing the shelf temperature into secondary drying before all of the ice is removed from the product will likely cause collapse or eutectic melt. Thus, from product quality as well as process economics standpoint, it is very critical to detect the end of primary drying. This review focused on the recent advances and its targets in near future. At first, the principle, steps involved, formulation aspects and importance of lyophilization, methods of lyophilization with detection of end point in lyophilization was explained.On 21st century, in pharmaceutical field lyophilization has become important subject to ongoing development and its expansion. Lyophilization is common, but cost intensive. In old days process optimization was focused only on drying rather than lyophilization. But lyophilization was more (or) equally important for the process of pharmaceuticals. This review focused on the recent advances and its targets in near future. At first, the principle, steps involved, formulation aspects and importance of lyophilization was explained.

Keywords: End point of freeze-drying, Freeze drying, Freeze drying methods, Lyophilization.