In-line monitoring of alcohol precipitation by near-infrared spectroscopy in conjunction with multivariate batch modeling

Alcohol precipitation is a critical unit operation during the manufacture of Chinese herbal injections. To facilitate enhanced process understanding and develop control strategy, the use of near-infrared spectroscopy (NIRS) combined with multivariate statistical process control (MSPC) methodology was investigated for in-line monitoring of alcohol precipitation. The effectiveness of the proposed approach was evaluated through an experimental campaign. Six batches were run under normal operating conditions to study batch-to-batch variation or batch reproducibility and establish MSPC control limits, while artificial process variations were purposefully introduced into the four test batches to assess the capability of the model for real-time fault detection. Several MSPC tools were compared and assessed. NIRS, in conjunction with MSPC, has proven to be a feasible process analytical technology (PAT) tool for monitoring batch evolution and potentially facilitating model-based advanced process control of the alcohol precipitation during the manufacture of Chinese herbal injections.

Batch score control charts (t1) based on six NOC batches with control limits (±3 SD) dyed solid black line, and average trace marked by dotted black line: (a) batch 7, (b) batch 8, (c) batch 9, (d) batch 10.Figure optionsDownload as PowerPoint slideHighlights
► NIRS combined with MSPC was proposed for in-line monitoring of alcohol precipitation.
► MSPC control limits were established to detect and diagnose batch-to-batch variation.
► The method has proven to be a feasible PAT tool for monitoring batch evolution.