Optimization of determination of astragaloside Ⅳ in Astragali Radix by continuous single-factor method / 中国中药杂志

This paper aims to solve the problems of complicated-unstable test solution preparation process and insufficient extraction of the active ingredient astragaloside Ⅳ in the legal method for the determination of astragaloside Ⅳ in Astragali Radix. The continuous single-factor analysis of seven main factors affecting the content of astragaloside Ⅳ was carried out by HPLC-ELSD, and then the pre-paration method of test solution was optimized. This optimized method exhibited excellent performance in precision, repeatability and stability. The average recovery rate of astragaloside Ⅳ was 99.65% with RSD 2.2%. Astragaloside Ⅳ showed a good linearity between the logarithm of peak area and the logarithm of injection quantity in the range of 0.46-9.1 μg(r=0.999 6). The contents of astragaloside Ⅳ in 29 batches of Astragali Radix were determined by the new and the legal methods. The results showed that the average content of astragaloside Ⅳ in these Astragali Radix samples determined by the former method was 1.458 times than that of the latter one, indicating the new method was simple, reliable and more adequate to extract target compound. According to the results, it is suggested to improve the content standard of astragaloside Ⅳ in Astragali Radix in the new edition of Chinese Pharmacopeia.

Optimization of prescription and preparation technology of brucine nanostructured lipid carriers / 中草药

Objective To optimize the prescription and preparation technology of brucine nanostructured lipid carriers (B-NLC). Methods The method of "the solvent emulsification ultrasound" was used to prepare B-NLC. The prescription and preparation was optimized using a single factor method combined with central composite design-response surface methodology (CCD-RSM). Results The resultant B-NLC was transparent liquid with light blue opalescence. The optimal conditions were that the dosage of drugs was 1.28 mg, the mass concentration of poloxamer 188 was 1.08%, and the ratio of solid lipid to liquid lipid was 1.45:1. The obtained NLC showed the average particle size of (136.89 ± 4.23) nm with a polydispersity index of 0.289 ± 0.005 and a zeta potential of (-34.46 ± 0.31) mV. The entrapment efficiency was calculated to be (68.98 ± 2.06)%, and the drug loading content was (1.90 ± 0.06)%. Conclusion B-NLC prepared by solvent emulsification ultrasound had a high entrapment efficiency and a narrow particle size distribution. The method was easy and simple and can be used to optimize the prescription and preparation of B-NLC, which provides a foundation for the further in vivo research of brucine.