An approach combining real-time release testing with near-infrared spectroscopy to improve quality control efficiency of Rhizoma paridis.

Raw material examination is a critical process in the industrial production of traditional Chinese medicine (TCM); high accuracy and minimal time consumption are both required. In this study, near-infrared (NIR) spectroscopy was applied to improve the quality control efficiency of Rhizoma paridis. Partial least squares regression (PLSR) was first used to develop quantitative calibration models, and the discriminant analysis model was established to qualitatively discriminate the qualified samples from the unqualified samples. These two established NIR models were applied for real-time release testing (RTRT) of R. paridis. R. paridis saponins (RPS)≥0.6% and moisture ≤12% were used as the quantitative releasing criteria of RTRT according to the Chinese Pharmacopoeia. Qualified samples classified by the discriminant analysis model were deemed to meet the qualitative releasing criterion of RTRT. Using the established quantitative model, 24 samples were allowed to be released to the subsequent production processes with 100% accuracy. For the qualitative RTRT analysis, three samples were misclassified as the unqualified class and were released unsuccessfully, the accuracy of the qualitative RTRT was 90%. Therefore, the quantitative RTRT was more feasible for actual manufacturing processes. Based on this study, a rapid and effective quantitative NIR spectroscopic method was proposed for the RTRT of R. paridis. The combination of RTRT and NIR spectroscopy could be a potential tool to improve the quality control efficiency of R. paridis.