In situ UV fiber optics for dissolution testing – What, why, and where we are after 30 years

Abstract

Ultraviolet (UV) fiber optic spectroscopy has been applied to dissolution testing for more than 30 years. Multiple types of instrumentation schemes have been designed and implemented over that time, all aimed to introduce UV light into the dissolution apparatus to perform in situ measurement of the percent dissolved of the active pharmaceutical ingredient (API). In situ UV fiber optic systems provide many advantages over conventional dissolution testing. It generates real-time dissolution profiles with more frequent data points, providing rich information useful not only for regulated quality control tests, but also for formulation development, troubleshooting, and analysis of novel formulations, such as nanoparticles that are hard to filter. In situ UV measurement without filtration is challenging due to the effects of particulates and scattering. Mathematical “filters” including baseline correction and derivative spectroscopy can overcome these challenges and remove the contribution of non-API components. Innovative applications such as multicomponent dissolution, small volume bio-predictive dissolution, and biphasic dissolution are also being advanced by using in situ UV testing. More benefits are expected as the in situ UV methodology for dissolution is more broadly accepted and implemented in pharmaceutical arena.