Preparation and physicochemical characterization of a solid dispersion of (3, 5, 6-trimethylpyrazin-2-yl) methyl 3-methoxy-4-(3, 5, 6-trimethylpyrazin-2-yl) methoxy benzoate (VA-T) and polyvinylpyrrolidone / 中国天然药物

Ischemic brain injury is a major disease which threatens human health and safety. (3, 5, 6-trimethylpyrazin-2-yl) methyl 3-methoxy-4-[(3, 5, 6-trimethylpyrazin-2-yl) methoxy] benzoate (VA-T), a newly discovered lead compound, is effective for the treatment of ischemic brain injury and its sequelae. But the poor solubility of VA-T leads to poor dissolution and limited clinical application. In order to improve the dissolution of VA-T, the pharmaceutical technology of solid dispersions was used in the present study. VA-T/polyvinylpyrrolidone (PVP) solid dispersion was prepared by the solvent method. The dissolution studies were carried out and solid state characterization was evaluated by differential scanning calorimetry (DSC), infrared spectroscopy (IR), x-ray diffraction (XRD) and scanning electron microscopy (SEM). The dissolution rate of VA-T was significantly improved by solid dispersion compared to that of the pure drug and physical mixture. The results of DSC and XRD indicated that the VA-T solid dispersion was amorphous. The IR spectra showed the possible interaction between VA-T and PVP was the formulation of hydrogen bonding. The SEM analysis demonstrated that there was no VA-T crystal observed in the solid dispersions. The ideal drug-to-PVP ratio was 1:5. In conclusion, the solid dispersion technique can be successfully used for the improvement of the dissolution profile of VA-T.

Study on applicability of kinetic model for water extracts from puerariae radix / 中国中药杂志

To establish an appropriate experimental and data processing method on the basis of the general kinetic model for extraction of traditional Chinese medicines, in order to study the effect of total flavonoids in water extracts from Puerariae Radix on the adaptability of the model, with total flavonoids of Puerariae Radix as the determination indicator. The results showed that the natural logarithm of mass concentration of total flavonoids showed a good linearity with the changes in extraction time and solvent volume. Through calculating and fitting, we successfully established the kinetic model for water extraction of total flavonoids from Puerariae Radix, and verified its accuracy. Its good fitting degree and controllable deviation within the range of industrial production requirements indicated a good adaptability of the model. However, its equation correction factors require further studies.

Study on fingerprint of xiaochaihu granules sold in the market / 中国中药杂志

To establish a fingerprint of Xiaochaihu granules sold in the market with HPLC method, and study fingerprints of Xiaochaihu granules produced by different manufacturers and in different batches of the same manufacturer. Seven major index components were identified for the first time. The established method provided an all-around analysis on the quality assessment of Xiaochaihu granules.