Particle and Surface Characterisation Methods

thorough characterisation of surfaces is an increasing need in many, very different fields ranging from pharmaceutical development to polymer chemistry and development of medicinal devices. This concerns flat surfaces of e.g. films and membranes but also curved surfaces of particulates (solid particles, emulsions, liposomes) including their size analysis.

Size and surface properties determine e.g. the:
- physical stability of dispersions (suspensions, emulsions) - interaction between a surface and excipients (e.g. adsorption) - performance of dispersions in technical processes (e.g. flocculation) - adsorption of gases on powders and filter materials (e.g. as function of surface area) - interaction between surfaces and a biological environment (e.g. protein adsorption) - biocompatibility of surfaces (e.g. implants) - complement-activating properties of surfaces (e.g. of dialysis membranes) - substrate-specific adsorption (e.g. in blood purification, detoxication) - interaction of particles with cells (e.g. surface hydrophobicity) >A prerequisite for thorough characterisation are suitable analytical methods and instruments. Especially with regard to international guide-lines (e.g. GMP, GLP) the instruments require validation of software and hardware - a top issue in many companies.