Application progress of radiolabeled drugs in new drug research and development in China / 药学学报

The metabolism study of radiolabeled drugs plays an important role in the development of new drugs. It provides information on drug absorption, metabolism, tissue distribution and excretion, and plays an irreplaceable role in the metabolite safety evaluation and mass balance of new drugs. The new guidance draft on clinical trials of radiolabeled drugs recently released by the US FDA puts forward higher standards and has been widely concerned by the industry. In recent years, in the research and development of new drugs in China, 14C labeled drugs have been used to carry out clinical metabolism studies, which has overcome key technical bottlenecks and accumulated experience. This paper summarizes the above research progress, analyzes the existing problems, and preliminarily looks forward to the future technological development and application.

On the Commonness of San'ao Decoction and Its Analogous Formulas in Facilitating Fei / 中国中西医结合杂志

San'ao Decoction (SD) and its analogous formulas derived in the following generations are common used prescriptions for treating pulmonary diseases with principal symptoms such as cough and asthma. They are usually compatible with Chinese herbs for facilitating Fei, dispelling wind, resolving phlegm and fluid retention. Material bases in these formulas are mainly derived from Chinese drugs, but dissolution contents of active components are changed and new components are produced after compatibility. By multilevel effect evaluation, these analogous formulas all have commonness in ventilating Fei and superiorities of evidence-based derivation. The effect pathway of commonness was involved in cell structure protection, anti-inflammation, antioxidant, and immunoregulation.

Effects of stable isotope labeled internal standard on determination of ivabradine and N-demethylivabradine in human plasma / 药学学报

This study aims to develop a liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of ivabradine and N-demethylivabradine in human plasma, and investigate effects of stable isotope labeled (SIL) internal standard (IS) on ivabradine. The analytes and IS were extracted from plasma by protein precipitation with acetonitrile, and chromatographied on a Capcell PAK C18 (100 mm x 4.6 mm, 5 μm) column using a mobile phase of methanol and 5 mmol x L(-1) ammonium acetate. Multiple reaction monitoring with electrospray ionization (ESI) was used in the positive mode for mass spectrometric detection. The effect of ivabradine isotope peak [M+H+3] + on IS and the effect of SIL IS purity on ivabradine were evaluated. An appropriate concentration of SIL IS was chosen to permit method selectivity and linearity of the assay over the required range. The standard curves were demonstrated to be linear in the range of 0.100 to 60.0 ng x mL(-1) for ivabradine, and 0.050 0 to 20.0 ng x mL(-1) for N-demethylivabradine. The intra and inter day precision and accuracy were within the acceptable limits for all concentrations. Besides, the interaction between IS and ivabradine did not impact the determination of analytes. This method was successfully applied to a pharmacokinetic study of hydrogen sulfate ivabradine sustained release tablets on Chinese healthy volunteers.

Effect of San'ao Decoction on the airway inflammation and hyperresponsiveness in a murine model of lipopolysaccharide-enhanced asthma / 中国结合医学杂志

<p><b>OBJECTIVE</b>San'ao Decoction (, SAD), as a representative Chinese medicine (CM) formula, was chosen to evaluate the effect of airway inflammation and hyperresponsiveness on the lipopolysaccharide (LPS) enhanced asthma model.</p><p><b>METHODS</b>The asthma model was reproduced in the Balb/C mice sensitized by ovalbumin (OVA), challenged by OVA and LPS. After Balb/C mice's administration of a dose (0.0024 g/kg) of dexamethasone acetate, and three doses (2.2 g/kg, 4.4 g/kg and 8.8 g/kg) of SAD, airway inflammation and responsiveness were observed. The airway inflammation was detected by counting bronchoalveolar lavage fluid (BALF) cells and lung histopathology. Also, differential expressions of interferon-r (IFN-γ), interleukin-4 (IL-4), and IL-5 in the supernatants of BALF were examined. The changes in airway responsiveness indicated by lung resistance (R(L)) and stimulated by acetylcholine (Ach) were determined.</p><p><b>RESULTS</b>Small-dose SAD hardly inhibit airway inflammation or hyperresponsiveness in the LPS-enhanced asthma, while medium-dose and high-dose SAD significantly inhibited the airway hyperresponsiveness, and to some extent, reduced airway inflammation. Meanwhile, the small-dose, medium-dose, and high-dose SAD promoted Th1-type cytokines (IFN-γ) and reduced Th2-type cytokines (IL-4, IL-5) to different extents, which led to a Th1/Th2 balance.</p><p><b>CONCLUSION</b>SAD has a good therapeutic effect on airway hyperresponsiveness in the LPS-enhanced asthma model, but its definite influence on airway inflammation is not remarkable.</p>