ASSESSMENT OF THE WETTABILITY OF PHARMACEUTICAL POWDERS

There is Considerable interest in the assessment of the wettability of pharmaceutical powders, as the data can be used to give indications o f product performance (in terms of a crude predictor of rates of drug release from dosage forms, or as a guide to the interfacial interactio ns between components of a formulation). However, contact angle method s for powders are problematic, in particular because powders have hete rogeneous and rough surfaces, and these ale often capable of rapid cha nges in properties. The different approaches to contact angle assessme nt are reviewed, and some advantages of vapour sorption experiments ar e discused.