ABSTRACT
Reflectance near-infrared (NIR) spectroscopy has been investigated as a method to distinguish between the sites of manufacture of a number of proprietary tablets. As test samples, parallel imports which are pharmaceutically equivalent products manufactured at different sites have been used. Three products: Aremis/Besitran, Renitec and Voltarol Retard originating from two or more sites and Adalat from a single site were examined. The principal component analysis (PCA) score plots showed that spectra of tablets originating from different sites of manufacture often gave rise to statistically different populations. PCA loadings indicated that the differences were related to moisture content and excipients. Spectra were used to construct a library for the classification of tablets to predict the site of manufacture based on the method of residual variance of the principal components. Where a large data set was available (Aremis/Besitran tablets) prediction rates for the successful identification of the two sites of manufacture, Madrid and Barcelona, were 95.7 and 98.1%, respectively for the validation set with all errors encountered of Type I.
