Changes in the dissolution of tolbutamide by a traditional Chinese medicine, Sho-saiko-to (Xiao Chaihu Tang)

The evaluation of the chemical quality and UV overall components dissolution consistency of Flos Chrysanthemi Indici preparation

In recent years, new chemical technology and chemical analysis methods have been widely used for the quality control of medicine to provide security for human life. However, for the increasingly popular traditional Chinese medicine (TCM) preparations, the traditional quality control technology has been challenged due the presence of multi-components. To solve this problem, this study proposed a comprehensive evaluation strategy from two aspects: chemical quality and in vitro dissolution consistency. Zhenju antihypertensive tablet (FCIP), as the research object of this study, is a compound preparation of Flos Chrysanthemi Indici with moderate antihypertensive effect. For the chemical quality, the capillary electrophoresis fingerprint (CE-FP) was established based on the characteristic multi-wavelength averaging fusion profiling (CMW-AFP) strategy, which can fuse peaks in the CE chromatogram at several select characteristic wavelengths into one profile through an averaging algorithm. All samples were clarified into 5 quality grades using the systematic quantified fingerprint method, and showed significant difference among the four manufacturers. Combined with the accurate determination of the marker components, the CE-FP evaluation results can provide a guarantee for the chemical quality consistency. For the in vitro dissolution consistency, a UV overall components dissolution method was proposed. Meanwhile, in order to match the established UV overall dissolution system, two f2 factors (f2-R and f2-MI) were calculated to compare the dissolution profiles. By comparing the chemical and UV overall dissolution results plus the PCA analysis, the holistic quality of the FCIP samples of four manufacturers were obtained as MA > MC > MD > MB. The established evaluation system is also a suitable strategy for controlling the chemical quality and dissolution consistency of other TCM preparations.

A novel method for quality consistency evaluation of Yankening Tablet by multi-wavelength fusion profiling combined with overall components dissolution method and antioxidant activity analysis

Yankening Tablet (YKNT) is an anti-inflammatory Chinese medicine, which has the effect of heat-clearing and purging pathogenic fire. In this paper, a novel method for quality consistency evaluation of YKNT by multi-wavelength fusion profiling combined with multi-component quantification, overall components dissolution method and antioxidant activity analysis was established. The five-wavelength fusion fingerprint (FWFFP) of 19 batches of YKNT was established, which was evaluated qualitatively and quantitatively by systematic quantified fingerprint method (SQFM), and the quality of YKNTs was divided into different grades successfully. Three active components, Berberine (BBR), baicalin (BCL) and chrysophanol (CRP) in YKNT, were quantitatively determined by quantitative analysis of multi-components by single marker (QAMS). Principal component analysis divided the 19 batches of samples into two categories according to the content difference, which was consistent with the SQFM evaluation results. The combination of SQFM and QAMS successfully achieved the quantitative determination of YKNT from the whole to accurate. Partial least squares (PLS) model was developed to explore the relationship between the antioxidant ability and fingerprint of YKNT. Further overall dissolution UV fingerprints (ODUV-FP) were successfully established, in which the ultraviolet fingerprint (UV-FP) quantitative method was applied to determine the dissolution of the whole chemical substance of traditional Chinese medicine (TCM) preparation. HPLC fingerprints (HPLC-FP) and ODUV-FP were combined to realize the dual control of the quality and efficacy of YKNT, providing a new method for consistency evaluation of TCM.

Hepatoprotective and Anti-fibrotic Agents: It's Time to Take the Next Step

Hepatic fibrosis and cirrhosis cause strong human suffering and necessitate a monetary burden worldwide. Therefore, there is an urgent need for the development of therapies. Pre-clinical animal models are indispensable in the drug discovery and development of new anti-fibrotic compounds and are immensely valuable for understanding and proofing the mode of their proposed action. In fibrosis research, inbreed mice and rats are by far the most used species for testing drug efficacy. During the last decades, several hundred or even a thousand different drugs that reproducibly evolve beneficial effects on liver health in respective disease models were identified. However, there are only a few compounds (e.g., GR-MD-02, GM-CT-01) that were translated from bench to bedside. In contrast, the large number of drugs successfully tested in animal studies is repeatedly tested over and over engender findings with similar or identical outcome. This circumstance undermines the 3R (Replacement, Refinement, Reduction) principle of Russell and Burch that was introduced to minimize the suffering of laboratory animals. This ethical framework, however, represents the basis of the new animal welfare regulations in the member states of the European Union. Consequently, the legal authorities in the different countries are halted to foreclose testing of drugs in animals that were successfully tested before. This review provides a synopsis on anti-fibrotic compounds that were tested in classical rodent models. Their mode of action, potential sources and the observed beneficial effects on liver health are discussed. This review attempts to provide a reference compilation for all those involved in the testing of drugs or in the design of new clinical trials targeting hepatic fibrosis.

Effects of Chinese Herbal Medicines on Intestinal Drug Absorption

Sho-saiko-to (Xiao-Chai-Hu-Tang), one of the major traditional Chinese medicines, has been frequently prescribed with other synthetic or biotechnological drugs for the treatment of various acute or chronic diseases in Japan, and thus it is important to understand the interactions between Sho-saiko-to and coadministered drugs. This paper reviews the effects of Sho-saiko-to on the pharmacokinetics and pharmacodynamics of concomitant drugs in the gastrointestinal tract. Sho-saiko-to slightly hastens the gastrointestinal absorption of the sulfonylurea compound tolbutamide. Furthermore, it is considered that the increase in the gastrointestinal absorption rate by Sho-saiko-to may potentiate the hypoglycemic effects of tolbutamide in the early period after oral administration. Sho-saiko-to can facilitate the epithelial membrane permeability of tolbutamide at an early phase across the rat jejunum in situ and Caco-2 cell monolayers. It is also suggested that Sho-saiko-to enhances the energy-dependent transport of tolbutamide and has an inhibitory effect on the passive paracellular transport of tolbutamide in Caco-2 cells. This result might be related to the accelerated in vivo absorption rate of tolbutamide by concomitant dosing with Sho-saiko-to in rats. In addition, Sho-saiko-to has inhibitory effects on the efflux pump mediated by MDR1, and it appears that the crude constituents in Glycyrrhizae radix, glycyrrhizic acid and liquiritin, contribute to MDR1 suppression.

Transepithelial Permeation of Tolbutamide across the Human Intestinal Cell Line, Caco-2

Sulfonylurea hypoglycemic agents have interindividual variability in the gastrointestinal absorption rate. However, the absorption mechanism at the intestinal epithelium has not yet been clarified. To elucidate contribution of the specific mechanism for transepithelial transport of sulfonylureas, the apical-to-basolateral and basolateral-to-apical transport studies of tolbutamide were carried out using Caco-2 cell monolayers cultured on the polycarbonate membrane. The transported amounts of the substrate were measured by HPLC to estimate the apparent permeability coefficients (P(app)). In the apical-to-basolateral flux, the transport activity of tolbutamide was facilitated when the pH of the apical medium was more acidic than the basolateral one. ATP-depletion decreased the P(app) of tolbutamide. The kinetic analysis of the permeation rate indicated that the saturable process largely contributed to the tolbutamide flux. The P(app) of tolbutamide was lowered by an ionophore and monocarboxylic acids, while dicarboxylic acids and the inhibitor for the anion exchanger had no effect. In addition, mutual inhibition with benzoic acid was observed in transepithelial transport of tolbutamide. On the other hand, the permeation rate of tolbutamide from the basolateral to apical side was concentration-independent and neither affected by metabolic inhibitors, probenecid nor inhibitors for P-glycoprotein. In conclusion, these results suggest that apical-to-basolateral transport of tolbutamide across the Caco-2 cell monolayers is mediated by the pH-dependent specific system, presumably shared with other organic anions such as benzoic acid.