Flow reaction system for automated forced degradation testing

Forced degradation or accelerated degradation is a process whereby the natural degradation rate of a product or material is increased by the application of an additional stress.

Introduction

Forced degradation studies are used to identify reactions which may occur to degrade a processed product. Usually conducted before final formulation, forced degradation uses external stresses to rapidly screen material stabilities.

Longer term storage tests are usually used to measure similar properties when final formulations are involved because of the stringent FDA regulations. These tests are generally more expensive (because of the time involved) than forced degradation which is therefore used for rapid selection and elimination tests.

Common stresses

There are a number of common stresses which are used to

• pH (acid/base)

Chemical processes are often catalysed by the presence of acids and bases. The exposure of materials to these can therefore accelerate degradation reactions.

• Temperature

In accordance to arrhenius kinetics, increasing temperature increases the rate of any degradation process. The Arrhenius equation is a simple but remarkably accurate formula for the temperature dependence of the Rate constant, and therefore rate of a chemical reaction Temperature is often used in conjunction with other stresses to increase reaction rates.

• Oxidation
• Concentration
• Light

Methodologies

Standard methodologies include:

• Wet chemistry methods
• Flow chemistry
• Calorimetry
• HPLC

Application

See also

• Chemical decomposition
• Thermogravimetric analysis

External links

• Flow chemistry degradation by Syrris