Extraction, separation, and in vitro dissolution of HgS micro & nano-particles from Mongolian medicine Menken Usu / 中草药

ABSTRACT

Objective To study the extraction, separation, and in vitro dissolution method of HgS micro & nano-particles from Mongolian medicine Menken Usu. Methods The Soxhlet extraction method was used to investigate the sulfur from Menken Usu effectively, and the optimum time of extraction was determined by investigating the influence of different extraction time on the extraction rate of sulfur in the Menken Usu. Then, the mercuric sulfide particles were separated by differential centrifugation. The mercuric sulfide micro & nano-particles with different particle sizes can be obtained by controlling the concentration of PVP, molar ratio, centrifuge speed, and other factors. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to analyze the morphology and composition of the particles. Using dithizone colorimetric method to determine and compare the dissolution of HgS particles with different sizes, Menken Usu original herbs, and Menken Usu-18 in simulated human gastric and small intestinal. Results The SEM results showed that the obtained six mercuric sulfide particle samples have a uniform size distribution Uniform size were 2 000-4 000, 800-2 000, 200-800, 80-200, 50-80, and 20-50 nm. The main components in the extracted samples were α-HgS and β-HgS. As the particle size of HgS gradually became smaller, the dissolution of mercury was increased, which indicated that the size of HgS particle was inversely related to the dissolution of mercury. At the same time, the dissolution of mercury is also affected by sulfur, pH, and compounds. Conclusion This is a simple and efficient method for the separation of mercuric sulfide particles, and provides the basis for the pharmacokinetics and pharmacological study of mercuric sulfide nanoparticles with different particle size.