Binding effect of fluorescence labeled glycyrrhetinic acid with GA receptors in hepatocellular carcinoma cells.

Glycyrrhetinic acid (GA) is a natural active component from licorice, which is broadly used in traditional Chinese medicine. Lots of glycyrrhetinic acid receptors (GA-R) are proved to locate on the surface of liver cells. Many reports about the hepatocellular carcinoma (HCC) treatment were dependent on GA modified carriers. However, the reality of GA-R in HCC cells was not clear. In this paper, 18ß-glycyrrhetinic acid (18ß-GA) was labeled with fluorescence (FITC) by chemical synthesis. Together with the binding effect of fluorescence labeled glycyrrhetinic acid (FITC-GA), the competitive action of 18ß-GA with GA-R was investigated in HCC cells. The results showed that in HepG2 cells, 18ß-GA and FITC-GA presented similar cytotoxicity. The specific binding saturation of GA showed the dissociation constant (Kd) was 7.457±2.122pmol/L and the maximum binding counts (Bmax) was 2.385±0.175pmol/2.5×106 cells, respectively. FITC-GA bound to cytomembrane specifically and 18ß-GA competed to bind the sites significantly in HepG2 cells. Therefore, there is binding effect between fluorescence labeled GA and GA-R. The GA-R on HCC cells is confirmed as expected, which provides a useful reference of active target modified by GA and a novel approach for receptors and ligands study.

Preparation, optimization and characteristic of huperzine a loaded nanostructured lipid carriers.

The objective of the present work was to study the preparation, optimization and characteristics of Huperzine A (Hup A), an effective Traditional Chinese Medicine treatment of Alzheimer's disease (AD), loaded nanostructured lipid carriers (NLC). NLC were successfully prepared by a modified method of melt ultrasonication followed by high pressure homogenization using Cetyl Palmitate (CP) as the solid lipid, Miglyol((R))812 as the liquid lipid, Soybean phosphatidylcholine (Spc) and Solutol HS15 as the emulsifiers. The best formulation was optimized with a three-factor, three-level Box-Behnken design. Independent variables studied were the amount of the mixed lipid, the amount of the emulsifier mixture and lipid/drug ratio in the formulation. The dependent variables were the particle size, entrapment efficiency (EE) and drug loading (DL). Properties of NLC such as the morphology, particle size, zeta potential, EE, DL and drug release behavior were investigated, respectively. As a result, the designed nanoparticles showed nearly spherical particles with a mean particle size of 120 nm and -22.93 + or - 0.91 mV. The EE (%) and DL (%) could reach up to 89.18 + or - 0.28% and 1.46 + or - 0.05%, respectively. Differential scanning calorimetry (DSC) of Hup A loaded NLC indicated no tendency of recrystallisation. In vitro release studies showed a burst release at the initial stage and followed by a prolonged release of Hup A from NLC up to 96 h. The results suggest that the presented Hup A loaded NLC system is a potential delivery system for improving drug loading capacity and controlled drug release.

Preparation and characterization of nanostructured lipid carriers loaded traditional Chinese medicine, zedoary turmeric oil.

BACKGROUND: The objective of this work was to study the preparation and characteristics of zedoary turmeric oil (ZTO), a traditional Chinese oily medicine, loaded with nanostructured lipid carriers (NLCs). METHOD: Aqueous dispersions of NLC were successfully prepared by melt-emulsification technique using Crodamol SS as the solid lipid, Miglyol 812N as the liquid oil, and soybean phosphatidylcholine (SbPC) as the emulsifier. Properties of NLC such as the particle size and its distribution, the transmission electron microscope (TEM), drug entrapment efficiency (EE), and drug release behavior were investigated, respectively. The Germacrone blood concentration after intravenous administration of ZTO-NLC was determined and compared with that of ZTO-injection. RESULT: As a result, the drug EEs were improved by adding the liquid lipid into the solid lipid of nanoparticles (SLNs). In vitro drug release experiments indicated that the prepared NLC could enhance the drug release rate over the SLN, and the drug release rate could be adjusted by the liquid lipid content in lipid nanospheres. X-ray and differential scanning calorimetry (DSC) measurements revealed that imperfect crystallization occurred in the inner core of the NLC particles. CONCLUSION: The results suggest that the presented NLC system might be a promising intravenous dosage form of water-insoluble oily drugs.

[Preparation and study in vitro of long-circulating nanoliposomes of curcumin].

OBJECTIVE: To prepare the long-circulating nanoliposomes of curcumin. METHOD: The long-circulating nanoliposomes were prepared by ethanol infusion and the encapsulation efficiency was determindated by the mini-column centrifugation. The effect of some factors on the encapsulation efficiency, such as the buffer solutions, the weight ratio of curcumin to SPC, the weight ratio of SPC to Chol, the pH of buffer solution and the iron strength of water phase, was investigated respectively. Then the formulation was optimized by orthogonal design. RESULT: The encapsulation efficiency of the curcumin liposomes was (88.27 +/- 2.16)%, and the average diameter of the liposomes was (136 +/- 18) nm. There was no change on encapsulation efficency within 30 d. CONCLUSION: The preparation of curcumin liposomes was easy and practicable and the pharmaceutical characterization showed that the curcumin liposomes are stable.

[Study on influence of buffer system on separate capacity of macroporous resin on ferulic liposome].

OBJECTIVE: To study the effect of buffer on separate capacity of macroporous resin. To evaluate the quality of ferulic acid liposome and determine its entrapment efficiency. METHOD: Different type of macroporous resin counterpoised by buffer system of Na2 HPO3-NaH2, PO3 was used to separate the free ferulic acid from the preparation and HPLC was used to determine the concentration of the ferulic acid to calculate the entrapment efficiency. RESULT: This method had good linearity in the range of 0.56 - 2.8 g x mL(-1) (r = 0.999 6). The precision RSD was less than 1.1%. The adsorption effect of macroporous resin on liposome was reduced while it had no effect on the absorption ability of macroporous resin on the ferulic acid by the usage of buffer. The recovery of HPD450 resin on blank liposome was between 97.2% - 100.8%, while the average recovery is 98.1%. CONCLUSION: Buffer system can enhance the separate ability of macroporous resin on liposome and free drug.

[Study on the preparation of rapid-dissoluted EGb droppills].

OBJECTIVE: To study the formulation and technique of preparation of rapid-dissoluted EGb (Extract of Ginkgo biloba) droppills. METHOD: Taking the dissolution percentage of total flavonoids in EGb and weight variation as index, the formulation and technique of EGb droppills were optimized by the orthogonal experiment. RESULT: T50 was 3.62 min and mean weight variation was 2.80%. CONCLUSION: Rapid-dissoluted EGb droppills can increase the dissoluting rate distinctly and reach the purpose of preparation.