Using Texture Analysis technique to assess the freeze-dried cakes in vials.

A freeze-dried (FD) cake should possess, among others properties, a sufficient dryness and strength to prevent cracking or powdering during transportation and storage. In the present work the application of a standard Texture Analysis (TA) technique to study the mechanical properties of the FD cakes directly in glass vials used for freeze-drying has been demonstrated. Examining the FD cakes in glass vials has many advantages as it allows studying the intact FD cakes minimizing the bias from texture distortion during samples preparation, and reducing the moisture uptake. A procedure allowing quantitative assessment of the strength, fracturability and elastic properties of the FD cakes using Texture Analysis has been developed. The results show that the TA method is sensitive to the variations in cake materials, storage conditions (temperature, excessive moisture) and cake quality. The results also show that TA can also be applied for optimization / improvement of the freeze-drying protocols and rapid disintegrating tablet formulation development. The simplicity of the Texture Analysis technique and a number of different probes available on the market allow using the TA for the routine reliable and robust tests of freeze-dried solids providing valuable information on the strength and texture of the cakes.