Micrometer sized particles seen through the lens of a microscope: Image analysis of pharmaceutical powders and suspensions

摘要

From the moment around 1670 that Antonie van Leeuwenhoek as the 'father of microscopy' presented his version of the optical microscope (Figure 1), millions of people have been fascinated by the beauty of the microscopic world. Nevertheless, it was not until the late 20th century that computer technology allowed one to routinely use optical microscopy for the automated acquisition, processing and analysis of large series of images. Nowadays, Static Image Analysis (SIA) and Dynamic Image Analysis (DIA) have become indispensable tools in the particle size and shape distribution analysis of pharmaceutical powders and suspensions [1,2]. However, though a significant number of manufacturers make SIA and DIA systems commercially available, serious differences may exist in the way these systems operate. In this paper, a schematic overview is presented on the microscopic size and shape distribution analysis of micrometer sized particles, and the various technical solutions that allow one to do this.