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.

Absorption of aqueous extracts from Salviae Miltiorrhizae Radix et Rhizoma by everted intestinal sac method / 中国中药杂志

To study the absorptive characteristics of aqueous extracts from Salviae Miltiorrhizae Radix et Rhizoma by in vitro rat everted intestinal sac model. Three representative ingredients in aqueous extracts from Salviae Miltiorrhizae Radix et Rhizome--protocatechuic aldehyde (PAL), posmarinic acid (RA) and salvianolic acid B (SAB), were selected as the study objects. An UPLC method was established to determine and measure their cumulative absorption amount, in order to explain the absorption characteristics of ingredients in different intestinal sections. According to the experimental result, RA and SAB showed the passive absorption in ileum, which conformed to the first-order absorption rate; with low and medium doses, they showed a zero-order absorption rate in jejunum, which was reflected in the coexistence of both positive and passive absorptions; PAL showed a passive absorption manner both in ileum and jejunum. According to the experiment for absorption in different intestinal sections, RA and SAB were mainly absorbed in jejunum, while PAL was absorbed mainly in ileum. All of the three ingredients in aqueous extracts from Salviae Miltiorrhizae Radix et rhizome--PAL, RA and SAB could be absorbed in intestines, but with differences in the absorption rate and mechanism, which indicated that the intestinal absorption of aqueous extracts from Salviae Miltiorrhizae Radix et rhizome was selectivity, instead of a simple semi-permeable membrane penetration process.

Quality analysis of scutellarin ethyl ester and its related substances / 中国药学杂志

OBJECTIVE: To establish an analytical method for simultaneous determination of scutellarin ethyl ester and its related substances by RP-HPLC and identify the main related substances by UPLC-MS. METHODS: The assay was performed on a Kromasil C18 column (4.6 mm×250 mm, 5 μm),and gradient elution was used with methanol-water containting 0.2% formic acid. The flow rate was 1.0 mL·min-1 and the detection wave length was set at 335 nm. The structure of the main related substance was identified by high resolution MS. RESULTS: Under the separation condition, the related substances were completely separated from the principal components. The calibration curve of scutellarin ethyl ester showed good linearity in the concentration range of 5.005-1001 mg·L-1 (r2=0.9999). The average recovery was 99.6%. The main related substance was identified as scutellarin by LC-MS. The contents of total impurities and scutellarin were 1.14% and 0.89%, respectively. CONCLUSION: The method is simple, efficient and accurate, and can be used for the quality control of scutellarin ethyl ester.