The NIR region of the spectrum mainly contains overtones and combination bands that are mainly attributed to hydrogen vibrations for bonds such as OH, CH and NH. Absorption of NIR radiation by these bonds causes molecules to rotate and vibrate. Pharmaceutical drugs and incipients give different NIR transmission spectra. NIR spectra are related to ingredients of the tablet parameters. Change in the content of the active component changes the NIR spectra and different reflectance and transmission spectra are obtained. By calibrating the spectra against samples of known values or measuring the tablet content with high accuracy techniques such as HPLC, a calibration curve can be obtained which relates the magnitude of the absorption peaks to the concentration of the active ingredients. This method can be used in content uniformity testing, which ensures the concentration of Active Pharmaceutical Ingredient (API) from tablet to tablet across an entire batch. Use our bigdatachem.com matching server that contains thousands of active substance and incipients used in the pharmaceutical industry.