Moisture sorption isotherms and Kinetics of active pharmaceutical ingredients (APIs), excipients and compound formulations are used for evaluation of their stability, processing requirements.

Interactions of propellant gases with inhaled products are similarly important to their dosing and storage properties.

Hygroscopic behaviour of excipient materials is used to control the properties of the end product.

Permeability to gases and Moisture Vapour Transfer Rates(MVTR) of packaging films can also be measured.

Polymorphism

Pharmaceutical ingredients can have several different polymorphs, or physical forms. These may have different crystal structures, non-crystalline amorphous forms, or they may be solvates or hydrates.

The physical and chemical properties of polymorphic forms can differ widely, with corresponding variations in the stability, chemical reactivity, dissolution rate, density and so on. For pharmaceutical development, these physical differences affect the manufacturing and processing requirements of pharmaceutical products, as well as the stability, storage and activity of the final product.

Characterisation of the moisture and solvent sorption properties of different polymorphs is an essential part of the drug development process.

The Hiden Analytical HPR-20 gas analyser is used to sample gas composition during Chemical Reaction processes, using measurements of evolved gas composition for reaction rate monitoring and endpoint detection.