ABSTRACT
Objective: To establish simultaneous determination method of eight main flavonoids from Puerariae Lobatae Radix (PLR) by using UPLC, and to study the effect of ultrafine grinding technology on the content of flavonoids in PLR for optimizing its production process. Methods: Response surface method was used to investigate the crushing time, sampling capacity, and initial particle size in the superfine pulverizing technology of PLR. Using the particle size distribution (D50, D90), and the content of eight flavonoids (3′-hydroxy puerarin, puerarin, 3′-methoxy puerarin, daidzin, genistin, daidzein, genistein, and formononetin) from PLR powders with various particle sizes (10—40, 40—65, 300 mesh) determined by UPLC, we selected these 10 elements as the response factors to evaluate the ultrafine powders technology for PLR. Results: Eight flavonoids from PLR had a good linear relationship with the linear range of 75.8—242.7, 205.6—658.0, 147.3—417.3, 10.2—163.3, 11.3—182.0, 1.2—18.8, 0.25—4.00, 0.35—5.37 μg/mL, and the average recovery ranged from 98.86%, 99.25%, 99.90%, 100.17%, 100.21%, 101.40%, 100.73%, and 101.42%. In addition, the repeatability, stability, and precision RSD were all less than 3%. UPLC result showed that, compared with the PLR powders with other particle sizes, the ultrafine powder of PLR (300 mesh) had a higher flavonoids contents. Results: of response surface method showed the optimized preparing parameters of PLR ultrafine powder technology as follows: 80 mesh [(180 ± 7.6) μm] of particle size, 247 g of sampling amount, and 26 min of crushing time. Conclusion: Optimization of ultrafine powders process from PLR by response surface method is simple and accurate, which can obtain PLR ultrafine powder with higher content of flavonoids. This process can provide reference for the ultrafine grinding technology of PLR.