Simple transmission Raman measurements using a single multivariate model for analysis of pharmaceutical samples contained in capsules of different colors

► Transmission Raman spectra of samples in glass vials were collected. ► A PLS model was developed using these spectra. ► This model was directly used to determine concentrations of the same samples in capsules of different colors. ► Fluorescence emanating from capsules was reduced by the transmission measurement. ► Accurate determination was feasible without influence of capsule colors seriously.