Discriminant analysis on first ten principal components was carried out for statistical evaluation both for capsules and tablets; each batch of a drug was considered as a separate class. The obtained values of spectral range in Mahalanobis units were used to assess batch-to-batch reproducibility and describe production variability of different manufacturers. The authors also have used the discriminant analysis to compare the following groups - each separate batch against all the remaining series range (so-called spectral library). The analysis resulted in a lower spectral difference between the classes, then in case of batch-to-batch matching. So it is recommended, every newly manufactured batch of the product should not uphold the general product class more than the value of the specified spectral range.