Development and validation of a high-throughput GC measurement for water activity

The development and validation of a headspace GC method to measure the water activity of pharmaceutical samples is presented. Thermal and moisture transfer equilibration rates are shown to be critical variables in the measurement. Several different calibration schemes are discussed with their advantages and disadvantages. The high-throughput applications and experimental considerations of this approach are discussed. The method is shown to be a useful tool to measure a high throughput of water activity samples.