Arsenic speciation and valence / 中国中药杂志

As arsenic widely exists in nature and has been used in the pharmaceutical preparations, the traditional Chinese medicine(TCM) with arsenic include realgar(As_2S_2 or As_4S_4), orpiment(As_2S_3), and white arsenic(As_2O_3). Among the above representative medicine, the TCM compound formulas with realgar are utilized extensively. Just in Chinese Pharmacopoeia(2020 edition), there are 37 Chinese patent medicines including realgar. The traditional element analysis focuses on the detection of the total amount of elements, which neglects the study on the speciation and valence of elements. The activity, toxicity, bioavailability, and metabolic pathways of arsenic in vivo are closely related to the existence of its form, and different forms of arsenic have different effects on organisms. Therefore, the study on the speciation and valence of arsenic is of great importance for arsenic-containing TCMs and their compound formulas. This paper reviewed four aspects of the speciation and valence of arsenic, including property, absorption and metabolism, toxicity, and analytical assay.

Establishment and preliminary evaluation of multiple drug delivery system of effective components of Angelica sinensis / 药学学报

The multiple drug delivery system of components of traditional Chinese medicine is a system composed of multiple components and multiple units. According to the characteristics of each component, different drug delivery units are designed and combined to achieve the purpose of improving bioavailability and enhancing drug efficacy. In this study, supercritical extracts, phenolic acids, and polysaccharides derived from Angelica sinensis were examined as research objects, and a pellet-based vehicle was applied to construct a multiple drug delivery system for the treatment and chemoprevention of colitis and colorectal cancer. The extrusion-spheronization method was used to prepare pellets of Angelica polysaccharides which should be released in the stomach. The yield in 18-24 mesh and plane critical angle served as the index. The Box-Behnken design and the orthogonal design were used to optimize the formulation and parameters of pellets. According to a previous study, the colon specific pellets loading supercritical extracts and phenolic acid extracts were prepared by the optimized process. These two units of pellets were combined into the multiple drug delivery system of effective components of Angelica sinensis, and the quality evaluation and in vitro release study were conducted. The dynamic observation of pellets in mice was evaluated using small animal in vivo imaging system. The prescription of the Angelica polysaccharides gastric releasing pellets was:microcrystalline cellulose 6.5 g, polysaccharide 3.3 g, silica 0.2 g and 7 mL of 60% ethanol as wetting agent. The process parameters were as follows:extrusion rate at 75 r·min-1, rounding rate at 1 800 r·min-1, and rounding time for 3 min. Both in vivo and in vitro studies indicate that the prepared multiple drug delivery system of effective components of Angelica sinensis produced good release properties. The polysaccharide pellets could be rapidly released in the artificial gastric fluid and in the stomach. The colon specific pellets showed good targeting. They released little in the artificial gastric fluid within 2 hours, released less than 20% in the artificial intestinal fluid for 4 hours, and released more than 90% in artificial colon fluid for 6 hours.