The dissolution profile of intact tablets was predicted using diffuse transmission Near Infrared spectroscopy. Tablets compressed with varying levels of plasticizer were measured with an at-line NIR instrument and the spectra were correlated for regression with dissolution results. PLS1 models were developed to predict dissolution profiles for 24 hour sustained release solid dosage forms with equivalent error of the laboratory dissolution method. This method is in the spirit of QbD and PAT, and requires no solvents or buffers and no disposal of waste once the calibration model has been developed.