Hierarchically Nanostructured Fe3O4/C Composite as a Promising Magnetic Targeted Drug Nanocarrier.

Nanostructured Fe3O4/C composites are very attractive for high-performance magnetic targeted drug carriers. Herein, Fe3O4/C composite nanospheres with good dispersity are prepared by a simple one-step hydrothermal synthesis and subsequent heat treatment in Ar. The composite nanospheres consist of clustered primary nanoparticles, and exhibit a hierarchical architecture with a high specific surface area of 119.3 m² g-1. The Fe3O4/C composite nanospheres show a high saturation magnetization value of 101 emu g-1 and good biocompatibility. In particular, the composite nanospheres deliver a large loading content (85.8%) of epirubicin hydrochloride (EPI), resulting from their unique composition and microstructure. More importantly, the release of EPI from the EPI-loaded magnetic carrier (Fe3O4/C-EPI) may be enhanced by both a slightly acidic environment and a rotating magnetic field induced by a simple motor-driven magnet system. The above favorable properties make the hierarchical Fe3O4/C composite sample a promising candidate for magnetic targeting nanocarriers of EPI.

Simultaneous determination of six major stilbenes and flavonoids in Smilax china by high performance liquid chromatography.

A simple, sensitive and specific HPLC method was developed for simultaneous determination of the six major active constituents in Smilax china, namely taxifolin-3-O-glycoside (1), piceid (2), oxyresveratrol (3), engeletin (4), resveratrol (5) and scirpusin A (6), respectively. The samples were separated on an Aglient Zorbax XDB-C18 column with gradient elution of acetonitrile and 0.02% phosphoric acid (v/v) at a flow rate of 1.0 ml/min and detected at 300 nm. The six target compounds were completely separated within 35 min. All calibration curves showed good linearity (r2>0.999) within test ranges. The reproducibility was evaluated by intra- and inter-day assays and R.S.D. values were less than 3.7%. The recoveries were between 93.7 and 103.0%. The method was successfully applied to the analysis of six constituents in 15 commercial samples of S. china. The results indicated that the developed HPLC assay was readily utilized as a quality control method for S. china.

Chemical fingerprint and metabolic fingerprint analysis of Danshen injection by HPLC-UV and HPLC-MS methods.

HPLC-UV and HPLC-MS techniques were used in fingerprint analysis of Danshen injection and its raw materials (roots and rhizoma of Salvia miltiorrhiza). HPLC profiles of Danshen injections from a Chinese pharmaceutical factory and their raw materials were established as their characteristic fingerprint and employed to assess their consistency and difference. To develop the representative fingerprint of Danshen injection, 10 batches of samples were analyzed under the same HPLC conditions. The results showed that 10 batches of Danshen injections had very similar HPLC fingerprints. To characterize the major constituents of Danshen injection for quality control, 11 major chromatographic peaks were characterized by their MS spectra and comparison with the reference standards. Through comparison of the HPLC profiles of Danshen injection with its raw material, it was found that they are greatly different, which indicated the changes of major constituents in the course of preparation procedure. In addition, the rat's plasma was analyzed by HPLC-MS technique after intravenous administration of Danshen injection at different time intervals to explore the in vivo metabolism of the major active constituents. Except for protocatechuic aldehyde, the major phenolic acids in Danshen injection appeared in rat's plasma after intravenous administration, but quantity of each phenolic acids was very different from that in Danshen injection. With the administration time prolonged danshensu and salvianolic acid B disappeared quickly, salvianolic D, lithospermic acid and salvianolic A slowly decreased and maintained relatively high concentration after 30 min of intravenous administration. This indicated that polyphenolic acids were significant for biological activity of Danshen injection. It might be concluded that chemical fingerprint combined with metabolic fingerprint is a useful means to control the quality and to clarify the possible mechanism of action of herbal products.