Determination of rat serum emodin level by microemulsion liquid chromatography with direct sample loading / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a microemulsion liquid chromatography system with direct sample loading for determining the serum level of emodin in rats.</p><p><b>METHODS</b>The separation was performed on C₁₈ column (Hypersil BDS, 5 µm,150 mm×4.6 mm) with the microemulsion mobile phase consisting of 3.3% (w/V) SDS, 6.6% (V/V) n-butyl alcohol, and 1.0% (V/V) octane and water. The flow rate was 1.0 ml/min and the detection wavelength was 254 nm.</p><p><b>RESULTS</b>The linear range of emodin detection was 0.333-5.32 µg/ml. The average recovery was 99.65% with a RSD of 3.60%. The limit of quantification was 0.1386 µg/mL.</p><p><b>CONCLUSION</b>Microemulsion liquid chromatography system with direct sample loading allows simple, accurate and rapid determination of emodin in rat serum.</p>

Micronization of magnolia bark extract by RESS as well as dissolution and pharmacokinetics evaluation / 药学学报

The purpose of this study is to explore the feasibility and superiority of using rapid expansion of supercritical solution (RESS) technology in the field of traditional Chinese medicine. The extract of magnolia bark (EMB) was obtained by supercritical carbon dioxide (SCF-CO2) extraction technology. Microparticles of EMB were manufactured by RESS technology. The effects of operating temperature and pressure on the contents of the active ingredient in the particles were evaluated by HPLC. The effect of expansion conditions on the particle size distribution of EMB particles was investigated. The smallest sample (mean size: 4.7 microm) was obtained under the RESS condition: pressure of 25 MPa, temperature of 50 degrees C and a nozzle size of 100 microm. The characteristics of microparticles were also studied by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and image analysis. The dissolution rate study showed that microparticles had a significantly faster dissolution rate than normal material particles. After oral raw EMB suspension, the mean areas under the plasma concentration-time curves (AUC(0-t)) of honokiol and magnolol were found to be (4.23 +/- 0.36) and (5.46 +/- 0.57) mg x h x L(-1), respectively, which were increased significantly, i.e. (5.41 +/- 0.63) and (7.24 +/- 0.83) mg x h x L(-1) when micronized EMB suspension was administered orally in SD rats (P < 0.05). Similarly, the mean maximum plasma concentrations of honokiol and magnolol increased from (1.55 +/- 0.22) and (2.35 +/- 0.14) mg x L(-1) (raw EMB) to (2.31 +/- 0.17) and (2.84 +/- 0.21) mg x L(-1) (micronized EMB), respectively. The results of t-test demonstrated that AUC(0-t) and Cmax value for honokiol and magnolol was significantly increased with the micronization compared to raw EBM (P < 0.05). This study demonstrated that the RESS was applicable for preparing microparticles of EMB at low operating temperature. The process was simple, free of environment pollution and without residual solvent.

Preparation of tanshinone transfersome and its deformability / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare tanshinone transfersome (TTs) and evaluate its deformability.</p><p><b>METHODS</b>The transfersomes were prepared by film dispersion method followed by sonication, and their physical properties, morphology, content, entrapment efficiency, particle size, polydispersity, and Zeta potential were investigated. The stability and deformability of TTs were studied. Liposomes with different molar ratios of cholate and lecithin were compared for their permeability under external pressure.</p><p><b>RESULTS</b>The prepared TF were spherical vesicles with content of 1.0192+/-0.075 mg/ml, entrapment efficiency of (62.3+/-0.08)%, particle size of 110 nm, polydispersity of 0.19 and Zate potential of -15.0 mV. The TTs remained stable during light-proof preservation for 3 months at 4 degrees C, and sodium cholate contributed to the flexibility of the lecithin vesicles.</p><p><b>CONCLUSION</b>TTs prepared by film dispersion method has good entrapment efficiency and stability. The vesicles possess high deformability in relation to the molar ratio of sodium cholate to lecithin and the external pressure.</p>