[Comparison of different administration routes of saikosaponin in plasma pharmacokinetics and brain pharmacokinetics].

To evaluate the optimum administration routes of saikosaponin in the treatment of epilepsy by comparing the plasma pharmacokinetics and the brain pharmacokinetics after different administration routes of saikosaponin. After receiving saikosaponin in different administration routes, the mice were sacrificed to collect the blood and brain tissues. The acetonitrile and methanol (9∶1) were used to precipitate the plasma protein. The concentration of the SSa in mice plasma and brain was determined by UPLC-MS/MS, and the pharmacokinetic parameters, bioavailability, the brain targeting coefficient (Re) and the brain drug targeting index (DTI) were calculated with Kinetica software. The relative brain Re was 142.17% by intranasal administration, with DTI of 3.06, significantly higher than those by the injections; in addition, the brain DTI was 1.25 by gavage administration. The brain drug targeting of saikosaponin by intranasal administration was higher than that by injection and gavage administration, indicating the advantages of the intranasal administration on medicine absorption into the brain.

[In vitro recovery rate of bullatine A microdialysis probe].

To establish UPLC-MS/MS method for determination of the recovery rate of bullatine A microdialysis probe. The concentration difference method(incremental method, decrement method) was used to measure in vitro recoveries, and the effects of perfusate pH value, flow rate, concentration, and temperature on the recovery rate were investigated to explore the feasibility of microdialysis for the pharmacokinetic study of bullatine A. The method of UPLC-MS/MS showed good linear relationship within the required range; the specificity, recovery rate and precision of chromatography met the requirements of microdialysis samples. There was no significant difference in the measured recovery rate between incremental method and decrement method. Under the same conditions, in vitro recovery rate of the probe was decreased with the increase of flow rate, and was significantly increased with the increase of temperature, but was independent of bullatine A concentrations around the probe. The results showed that, microdialysis technology can be used for the pharmacokinetic study of bullatine A, and retrodialysis method (decrement method) can be used for the determination of the in vivo recovery rate of bullatine A microdialysis.

[Pharmacokinetics of bullatine A in Aconitum brachypodum total alkaloids gel in transdermal delivery].

In this study, the changes of bullatine A in plasma and skin of mice with time in microemulsion gel and ordinary gel of Aconitum brachypodum total alkaloids were compared through UPLC-MS/MS, and their pharmacokinetic parameters were also compared and analyzed, to investigate the feasibility of microemulsion agent in the transdermal drug delivery. UPLC-MS/MS method for simultaneous determination of bullatine A in plasma and skin had high sensitivity and was in line with the pharmacokinetic study requirements for transdermal drug delivery. The main pharmacokinetic parameters for microemulsion gel in the plasma were as follows: Cmax=(37.62±14.31) µg•L⁻¹, Tmax=(3.40±1.34) h, AUC0-∞=(1 027.7±260) µg•L⁻¹â€¢h⁻¹, MRT=(34.80±12.31) h, MRTlast=(10.68±0.57) h, t1/2=(23.11±9.20) h; main pharmacokinetic parameters for ordinary gel in the blood: Cmax=(52.23±15.90) µg•L⁻¹, Tmax=(4.00±0.00) h, AUC0-∞=(728.60±280.80) µg•L⁻¹â€¢h⁻¹, MRT=(20.69±3.98) h, MRTlast=(9.34±0.42) h, t1/2=(14.69±3.15) h. The results showed that the microemulsion gel had more stable transdermal absorption, longer duration of action and higher bioavailability than ordinary gel, indicating that the microemulsion gel had a good and stable transdermal effect. There was no significant difference in bioavailability of bullatine A in skin between microemulsion gel and ordinary gel.

Targeting mesoporous silica-encapsulated gold nanorods for chemo-photothermal therapy with near-infrared radiation.

Mesoporous silica-encapsulated gold nanorods (GNRs@mSiO(2)) have great potential both in photothermal therapy and drug delivery. In this paper, we firstly developed GNRs@mSiO(2) as a synergistic therapy tool for delivery heat and drug to the tumorigenic region. We studied the ablation of tumor both in vitro and in vivo by the combination of photothermal therapy and chemotherapy using doxorubicin (DOX)-loaded GNRs@mSiO(2). Significantly greater cell killing was observed when A549 cells incubated with DOX-loaded GNRs@mSiO(2) were irradiated with near-infrared (NIR) illumination, attributable to both GNRs@mSiO(2)-mediated photothermal ablation and cytotoxicity of light-triggered DOX release. We then performed in vivo therapy studies and observed a promising tumor treatment. Compared with chemotherapy or photothermal treatment alone, the combined treatment showed a synergistic effect, resulting in higher therapeutic efficacy. Furthermore, the lower systematic toxicity of GNRs@mSiO(2) has been validated.