Liquisolid technique for enhancement of dissolution prosperities of tanshinone II(A) / 中国中药杂志

The technique of liquisolid compress is a new technique developed in 1990s, which was considered to be the most promising technique to improve the dissolution of water-insoluble drugs. In this article, tanshinone II(A) and the extracts of the ester-solubility fractions were chosen as the model drugs to evaluate the effects of the liquisolid technique for enhancement of dissolution properties of tanshinone II(A). Several liquisolid tablets (LS) formulations containing different dosage of drugs and various liquid vehicle were pre-pared and for all the formulations, microcrystalline cellulose and silica were chosen as the carrier and coating materials to evaluate their flow properties, such as angle of repose, Carr's compressibility index and Hausner's ratio. The interaction between drug and excipients in prepared LS compacts were studied by differential scanning calorimetry(DSC) and X-ray powder diffraction (XRPD). The dissolution curves of tanshinone II(A) from liquisolid compacts were investigated to determine the technique's effect in improving the dissolution of tanshinone II(A) and its impacting factors. According to the results, the dissolution increased with the rise in the dissolution of the liquid-phase solvent. The R-value and drug dosage can significantly affect the drug release, but with less impact on active fractions. This indicated that liquisolid technique is a promising alternative for improvement of dissolution property of water-soluble drugs, and can make a synergistic effect with other ester-soluble constituents and bettern improve the release of tanshinone II(A). Therefore, the technique of liquisolid compress will have a better development prospect in traditional Chinese medicines.

Study on application of bioassay method in drug-release evaluation in vitro of Salvia miltiorrhiza hydrophilic gel matrix tablets / 中国中药杂志

To investigate the feasible application of the bioassay method in the evaluation of traditional Chinese medicine sustained-release preparations, develop a rapid drug-release evaluation method in vitro for multi-component preparations, and replace the biological activity determination method characterizing the overall behavior with the existing drug-release evaluation method for single component, in order to give better instruction for sustained-release preparations. HPLC was adopted to determine dissolution media, drug releasing rates, and accumulative releasing of active ingredients (salvianolic acid B, protocatechuic aldehyde and rosmarinic acid) of Salvia Miltiorrhiza hydrophilic gel matrix tablets. The ultraviolet spectroscopy was adopted to determine the antioxidant activity of release media, and evaluate the correlation between the drug-time curve of various drug components and the drug-time curve of the total antioxidant activity. The correlation coefficient between the drug-release curve of various components and the drug-time curve of the total antioxidant activity was higher than the critical value r 0.898 (P < 0.001). This indicated that the drug-release curve of the three phenolic acids and the drug-time curve of the total antioxidant activity had a good correlation in different conditions, such as dissolution media, release rates and component ratios. The bioassay method for determination was feasible, simple and convenient for preparation quality evaluation and prescription design in the place of in vitro dissolution.

Pharmacokinetics of scutellarin and its derivant scutellarin ethyl ester in rats / 中国中药杂志

To develop a HPLC method for determination of the concentration of scutellarin and scutellarin ethyl ester and their pharmacokinetics were also compared. 104 mg kg-1of scutellarin or 114. 5 mg kg-1 scutellarin ethyl ester were given at single dose by oral gavarge. Blood samples were collected from the jugular vein. Plasma concentration was measured by HPLC. The pharmacokinetic parameters were calculated with Winnonlin program. The plasma concentration-time profile of scutellarin and scutellarin ethyl ester were both fitted with non-compartment model and both were double peaks. The main pharmacokinetic parameters of scutellarin and scutellarin ethyl ester were as follows: Tmax Cmax and AUC0-t for scutellarin were (6 +/- 1.26) h, (321.55 +/-48.31) microg L-1 and (2 974 +/-753) h micro.g L-1; for scutellarin ethyl ester, Tmax, Cmax and AUC0-t were 0.5 h, (1 550.82 +/-219.75) +/- microg L- and (6 407 +/- 399) h microg L-1. The speed ingested into the blood of scutellarin ethyl ester was faster than scutellarin, and the bioavailability of scutellarin ethyl ester was two times higher than scutellarin.

Studies on flash extraction methods of Arnebia euchroma / 中国中药杂志

The extraction of functional components from radix of Arnebia euchroma was optimized using orthogonal design based on the extraction yields of shikonin, and hydroxyl-naphthoquinone pigments. The data processing was carried out with the multiple guidelines grading method for optimizing the extraction condition. Compared with the traditional method (refluxing and ultrasonic extraction), the flash extraction method was more efficient The optimal conditions were as follows: 95% ethanol extract 3 times with 90 s for each. Under these conditions, the extraction yields of shikonin, and hydroxyl-naphthoquinone pigments were 93.16%, 93.89%, respectively, and the dry extract rate was 5.16%. In conclusion, the result showed that the flash extraction technology was appropriate, stable and feasible.