Investigation of drug distribution in tablets using surface enhanced Raman chemical imaging

► Raman chemical imaging was enhanced by applying SERS colloid on the samples. ► Distribution of trace amount of API was revealed below Raman limit of detection. ► Asymmetric least squares, a new method was used for baseline correction. ► MCR-ALS is required to resolve and identify SERS spectra and to create images. ► Proposed method intended for comparison of unknown samples with trace amount of drug.