Abstract

SCIENTIFIC TOOLS FOR CHARACTERIZATION OF SURFACE MORPHOLOGY OF SOLID STATE PHARMACEUTICALS

SwathimutyamPallerla, *Dr. BalaPrabhakar, Debendra Kumar Panda

ABSTRACT

The surface properties of solid state pharmaceuticals are of critical importance. Processing modifies the surfaces and effects surface roughness, which influences the performance of the final dosage form at many different levels. Surface roughness has an effect on, e.g., the properties of powders, tablet compression and tablet coating. The goal of this review is to understand the surface structures of pharmaceutical surfaces. In this context the specific purpose is to compare four different analysing techniques (optical microscopy, scanning electron microscopy (SEM), laser profilometry and atomic force microscopy (AFM)) in various pharmaceutical applications where thesurfaces have quite different roughness scale. It was found that optical microscopy was still a very efficient technique, as it yielded information that SEM and AFM imaging are not able to provide. Roughness measurements complemented theimage data and gave quantitative information about height differences. AFM roughness data represents the roughness of only a small part of the surface and therefore needs other methods like laser profilometer are needed to provide a larger scale description of the surface. The new developed roughness analysing method visualised surface roughness by giving detailed roughness maps, which showed local variations in surface roughness values. The method was able to provide a picture of the surface heterogeneity and the scale of the roughness.

Keywords: Optical Microscopy, Scanning Electron Microscopy (SEM), Laser Profilometry And Atomic Force Microscopy (AFM), Terahertz Pulsed Imaging (TPI).