Quantitative pharmaceutical analysis based on the PCA of Raman spectra

In the present work we examine the distribution of ciprofloxacin drug as an active ingredient in tablets samples from eight different laboratories. Additionally, control samples with different concentration were prepared for calibration. Raman spectra were recorded from all samples, including controls, and a principal component analysis (PCA) was implemented on them. The results of the PCA on control samples show that a clear discrimination among the different samples can be achieved and, more importantly, that the principal component of the Raman spectra has a well-defined, linear relation with the concentration of ciprofloxacin. Such a strong, statistically significant linear correlation obtained for the control samples constitutes our calibration for the quantitative analysis of commercial pharmaceutical compounds.