SPDS EXPERT REVIEW PANEL

B. Is there information demonstrating that the method meets the SMPR Method Performance Requirements using the Reference Materials stated in the SMPR? If not, then specify what is missing and how this impacts demonstration of performance of the method. method performs within the SMPR Method Performance REquirements table specifications for all analytes in the SMPR applicability statement? If not, please specify what is missing and whether or not the method's applicability should be modified. C. Is there information demonstrating that the

YES. The reference materials used in the method are five phenolic standards, caftaric acid, chlorogenic acid, cichoric acid, cynarin, and echinacoside from legitimate botanical standard suppliers.

YES. The required method performance parameters by SMPR include analytical range, LOQ, recovery, repeatability (RSDr) and reproducibility (RSDR). The method authors reported 6 calibration points for the 5 phenolic standards for linearity determination. The tested concentration range for each analyte is around 0.2 to 1000, 1 to 1000, or 2 to 1000 µg/mL, which is equivalent to the analytical range of 0.004% to 20%, 0.02% to 20% or 0.04% to 20% by w/w when weighing 125mg sample and dissolving in 25 mL of solvent. The method authors also give an effective analytical range as 0.004% to 6% for total phenolic contents (five of the phenolic compounds) after testing many different samples. These ranges meet the SMPR criteria for analytical range of 0.01% to 5% requirement. In the two SLVs from the supporting documents, the obtained limits of quantification were from 0.007% to 0.036% (w/w) and 0.003% to 0.012% for the five individual phenolic compounds, respectively, while the SMPR requires a general LOQ is not more than 0.01%. Therefore the LOQs meet or closely meet the SMPR criteria. In the same supporting documents, the recoveries were obtained in the range of 94.1% to 108% for the five individual phenolic compound and 97.6% to 99.8% for all the 5 phenolic compounds, respectively, meet the SMPR 90% to 107% criteria. In an interlaboratory collaborative study, the method authors reported the repeatability RSDr values 0.6% to 5.0% and the reproducibility RSDR 3.6% to 7.9% for precision evaluation after many tests on the different samples of three different Echinacea species, different plant parts (aerial or roots), and different dose forms (raw powder, powdered extracts, alcohol tincture). The results satisfy the SMPR RSDr and RSDR, which are not more than 6% and 8%, respectively, excepting for the high RSDr (6.9%) and RSDR (21.7%) for Echinacea glycerite tincture, which is suggested by the authors that the method is not suitable for the analysis of the analytes in tincture preparations.

IV. General Submission Package

A. Based on the supporting information, were there any additional steps in the evaluation of the method that indicated the need for any additional precautionary statements in the method?

NO. Since the chemicals and reagents related to the method are commonly used in analytical labs, such as acetonitrile, methanol, and phosphoric acid, plus the 5 individual botanical standards, no further precautionary statement is needed.