Optimization of the Integrated Processing Technology of Primary Processing for Asparagi Radix by HPLC-CAD Combined with the Box-Behnken Design

Background Asparagi Radix (AR) is one of the widely used Traditional Chinese Medicines (TCMs) for clinical applications, owning the effects of clearing the lungs and promoting body fluid, nourishing yin, and moistening the lung. To reduce the loss of active ingredients and improve production efficiency, the integrated processing technology of primary processing was used to obtain the decoction pieces of AR. However, there are no specific processing methods and index ingredients of AR in Chinese Pharmacopoeia (2020 edition). Materials and Methods This study aimed to establish a method of content determination of protodioscin and asparagine by high-performance liquid chromatography with charged aerosol detector (HPLC-CAD) as the index of process optimization. Furthermore, Box-Behnken design was used to optimize the integrated processing technology of primary processing. Results The result showed the contents of protodioscin and asparagine could reach 0.2678% and 0.4114%, respectively, both above the traditional process. After verification, the actual value (99.56) and predicted value (101.15) were similar, indicating that the integrated technology was feasible. In particular, the optimized process parameters of boiling time, drying time, and temperature were 25 min, 12 h, and 60°C, respectively. Conclusion In summary, these research findings may provide a reference for the primary processing and quality control of AR.