Well-mixed active substances for medications are indispensable in the pharmaceutical industry. This applies not only to the pharmaceutical active ingredient but also for lubricants, binding agents, explosives, oxidants and dyes. Analysis of these active ingredients is expensive; they are also only rarely analyzed as a rule. The progress of the mixing procedures can be followed conveniently with NIR spectroscopy, on the one hand using visual comparisons and on the other by means of spectral algorithms. The progress of mixing processes can be predicted in real time with the help of the spectrum when the latter is used.