Monitoring the dissolution of active pharmaceutical ingredient and TPGS in real time via IR spectroscopy during the manufacturing of liquid dosage formulation

► Dissolution of API and Vitamin E TPGS is monitored univariately via IR spectra. ► The developed calibration models apply to the scale-up spectra. ► Very good agreement with the HPLC assay is achieved. ► Prospects for real-time, online monitoring of the concentrations are discussed.