Real-Time Total Content Uniformity Assessment of Solid Dosage Forms Using Near-Infrared Transmission Spectroscopy

Real-time monitoring of solid dosage forms is crucial in continuous manufacturing processes for detecting product variability and bias and minimizing defective products. Traditional process analytical technologies often struggle to maintain high-throughput production. This study presents a novel approach using near-infrared (NIR) transmission spectroscopy for rapidly and comprehensively assessing the quality of solid dosage forms. A chemometric model was developed, based on NIR spectra obtained from tablets produced through wet granulation, to accurately predict active pharmaceutical ingredient (API). Performance was validated against the conventional high-performance liquid chromatography (HPLC) method, achieving a high correlation coefficient (R² = 0.9979) and a low root-mean-square error of prediction (RMSEP = 1.09%). Critically, even at a high inspection speed of 250,000 tablets/h, the method maintained high analytical accuracy (RMSEP = 1.19%) and met content uniformity requirements (±15%). With negligible bias compared with HPLC across all formulations, the proposed NIR transmission spectroscopy method offers a powerful alternative for the rapid and precise quantification of API content and real-time quality control, thereby substantially contributing to quality assurance in continuous manufacturing processes.