text: The moisture sorption properties of pharmaceutical materials such as excipients, drug formulations and packaging films are recognized as critical factors in determining their storage, stability, processing and application performance.  Further, vapor sorption experiments can be used to study hydrate and solvate formation. Gravimetric vapor sorption experiments are one of the most sensitive methods for determining amorphous contents, which may have a detrimental impact on the stability, manufacturability and dissolution characteristics of the formulated drug product.