Measuring and predicting pore size distribution of freeze-dried solutions

In this work, a novel procedure is presented for the measurement and prediction of pore size distribution of freeze-dried solutions in vials. A method based on segmentation is proposed for determining the size of the pores left by ice crystals, using images obtained by scanning electron microscopy. The original ice crystal size distribution is also predicted using a mathematical model based on balance equations. The model predictions and the results of the segmentation technique show a fairly good agreement. The proposed procedure could be used to efficiently estimate the resistance to mass transfer during drying and hence optimize the freeze-drying process.