Water Activity is a critical parameter in determining the safety and quality of pharmaceutical products. Measuring Water Activity in the pharma environment is described in USP<1112>. It is used as an indicator for chemical hydrolysis and microbial growth. Water Activity is defined by the partial vapor pressure of water in a substance divided by the vapor
pressure of water in standard state, expressed either as 0–100% equilibrium relative humidity (erh) or scaled to 0–1 water activity units (aw).
Dedicated instruments that measure Water Activity require up to 30 minutes for a single measurement. Using the XDS Masterlab Analyzer and Visible-Near Infrared Spectroscopy (Vis-NIRS), reliable results are now available in just a few seconds.


Metrohm AG

9100 Herisau