Qualitative determination of polyvinylpyrrolidone type by near-infrared spectrometry.

Soluble polyvinylpyrrolidones are very useful and versatile pharmaceutical auxiliaries. The different types of povidone are characterised by their viscosity measured in water, expressed as a K-value. We have developed a rapid, accurate, reliable, and non-destructive near infrared (NIR) spectroscopy method for the determination of PVP type and consequently identification thereof. We have implemented chemometrics onto NIR spectra collected in diffuse reflectance mode using fibre optics to build a qualitative model that enables us to obtain useful analytical information. A principal component analysis and a modelling technique soft independent modelling of class analogy (SIMCA) were applied. An approach to validate the method was developed.