Pharmacokinetics and efficiency of brain targeting of ginsenosides Rg1 and Rb1 given as Nao-Qing microemulsion.

Nao-Qing solution has been shown to be clinically effective in the treatment of acute ischemic stroke (AIS). The purpose of this study was to improve the pharmacokinetics and brain uptake of Nao-Qing, administered as an oil-in-water microemulsion. Sprague-Dawley (SD) rats were given Nao-Qing microemulsion by intranasal or intragastric routes. Samples of blood, brain, heart, liver, lung and kidney were collected at pre-determined time intervals, and the contents of ginsenosides Rg1 and Rb1 (active ingredients of the Nao-Qing microemulsion) were analyzed by high-performance liquid chromatography (HPLC). The results showed that contents of ginsenosides Rg1 and Rb1 in Nao-Qing microemulsion was 8475.13 ± 54.61 µg/ml and 6633.42 ± 527.27 µg/ml, respectively, and that the particle size, pH and viscosity of the microemulsion were 19.9 ± 5.07 nm, 6.1 and 3.056 × 10(-3 )Pas, respectively. Absorption of ginsenoside Rg1 was higher than that of ginsenoside Rb1, which was barely detectable after intragastric administration; furthermore, the concentration of ginsenoside Rg1 in blood and other tissues at each time point was lower for intragastric than for intranasal administration. Compared with intragastric administration, intranasal administration resulted in a shorter tmax (0.08 versus 1 h), a higher Cmax (16.65 versus 11.29 µg/ml), and a higher area under the concentration-time curve (AUC) (592.91 versus 101.70 µgch/ml) in the brain. The relative rates of uptake (Re) and the ratio of peak concentration (Ce) in the brain were 126.31% and 147.48% for ginsenoside Rg1, respectively. These data illustrate that intranasal administration can promote the absorption of drugs in Nao-Qing microemulsion and achieve fast effect.

Formulation and characterization of Brucea javanica oil microemulsion for improving safety.

OBJECTIVE: This study engaged in investigation of optimal formulation, characteristics analysis of Brucea javanica oil microemulsion (BJOM) in order to address safety concerns and make recommendations for improvements in BJOM safety during clinical use in vivo. METHODS: Pseudo-ternary phase diagram techniques were used to determine the appropriate ratio of surfactant, cosurfactant and oil phases. Subsequent stability testing of BJOM was performed by dilution, centrifugation and accelerated stability testing. The results were expounded through additional assessment utilizing the classical thermostat method to establish the shelf life of the material. These results were utilized to evaluate the safety of BJOM by haemolytic, irritative and allergic testing in vitro. In addition, the cytotoxicity of BJOM was examined using the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), with particular emphasis given to potential uses in cancer treatment. RESULTS: The most suitable method of preparation for BJOM was found to be a one to one ratio (Km 1:1) of Solutol HS15 surfactant matched with sorbitol cosurfactant in the ratio. The microemulsion droplets of BJOM possessed a spherical shape, uniform size and average diameter of 23.8 nm. The expiration date of BJOM was found to be 568 d. The safety study demonstrated no hemolysis activity at the experimental BJOM concentrations; however, mild hemolysis was observed at higher concentrations of Brucea javanica oil emulsion (BJOE), a common commercially available product. Irritation observed upon BJOM treatment can be primarily attributed to Brucea javanica oil (BJO) with little influence of BJOM excipients. In addition, BJOM caused no observed hypersensitivity or other visible allergic reactions in guinea pigs. The anticancer activity curves of BJOM and BJOE demonstrate that both BJOM and BJOE inhibit Hela cells, with BJOM demonstrating significantly more dramatic anticancer activity. CONCLUSION: An optimal formulation of BJOM superior to commercially available products and safe for medical application such as intravenous injection has been outlined along with its anticancer activity rating.