Use of roughness maps in visualisation of surfaces.

In this study we will present a new method to describe surface roughness. This method builds a roughness map of the studied area. The roughness map can give information of localised roughness. The test surfaces used in the evaluation of the method were tablets, which were made of lactose monohydrate, theophylline anhydrate, sodium chloride and potassium chloride. The roughness determinations were made by a laser profilometer. The new matrix method gives detailed roughness maps, which are able to show local variations in surface roughness values and provide an illustrative picture of the heterogeneity of surface roughness of various materials.

[1]  T. Yoshinobu,et al.  Mesoscopic Roughness Characterization of Grown Surfaces by Atomic Force Microscopy , 1994 .

[2]  Kinam Park,et al.  Fractal Analysis of Pharmaceutical Particles by Atomic Force Microscopy , 1998, Pharmaceutical Research.

[3]  P. Paronen,et al.  Dynamic solid-state and tableting properties of four theophylline forms. , 2001, International journal of pharmaceutics.

[4]  Hassan Zahouani,et al.  Effect of lateral resolution on topographical images and three-dimensional functional parameters , 1998 .

[5]  J. M. Cook,et al.  The fractal approach to heterogeneous chemistry , 1990 .

[6]  R. Rowe,et al.  The effect of the relationship between punch velocity and particle size on the compaction behaviour of materials with varying deformation mechanisms , 1986, The Journal of pharmacy and pharmacology.

[7]  J. Rantanen,et al.  Tablet surface characterisation by various imaging techniques. , 2003, International journal of pharmaceutics.

[8]  P. Wagberg,et al.  Surface profilometry : a comparison between optical and mechanical sensing on printing papers , 1993 .

[9]  C. R. Helms,et al.  Analyzing atomic force microscopy images using spectral methods , 1997 .

[10]  O. Antikainen,et al.  The effect of compression force on surface structure, crushing strength, friability and disintegration time of erythromycin acistrate tablets. , 1998, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[11]  G. Alderborn,et al.  Pharmaceutical Powder Compaction Technology , 1995 .

[12]  D. Landolt,et al.  Variable length scale analysis of surface topography: characterization of titanium surfaces for biomedical applications , 1998 .

[13]  G. Bolhuis,et al.  Materials for Direct Compaction , 1995 .

[14]  F. Podczeck.  Measurement of Surface Roughness of Tablets Made From Polyethylene Glycol Powders of Various Molecular Weight , 1998 .

[15]  David Avnir,et al.  The Fractal approach to heterogeneous chemistry : surfaces, colloids, polymers , 1989 .

[16]  Bruno C. Hancock,et al.  The relationship between the particle properties, mechanical behavior, and surface roughness of some pharmaceutical excipient compacts , 2003 .

[17]  K. Birdi.  Fractals and Geochemistry , 1993 .

[18]  A. Malinverno.  A simple method to estimate the fractal dimension of a self‐affine series , 1990 .

[19]  Surface profile estimation by digital filtering for wear volume calculation , 2002 .

[20]  F. Podczeck,et al.  Investigations into the deformability and tensile strength of pellets , 1998 .