Study on chitosan-modified tripterygium glycoside nanoparticles and its renal targeting property / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare chitosan-modified tripterygium glycoside nanoparticles (LMWC-TG-PLA-NPs), and assess its renal targeting property in rats.</p><p><b>METHOD</b>Chitosan-modified tripterygium glycoside nanoparticles (LMWC-TG-PLA-NPs) were prepared by modified spontaneous emulsification solvent evaporation method, and modified with 50% deacetylated low molecular weight chitosan (LMWC). The shape of nanoparticles was observed under a transmission electron microscope. The mean diameter of nanoparticles was measured by particle size analyzer. The drug encapsulation efficiency and drug loading were measured by centrifuge method. The in vitro release behavior was studied with dialysis bags. Renal microdialysis technique and renal artery administration technique were combined to study the renal targeting property of nanopartcles. LMWC-TG-PLA-NPs were administrated in rats by tail vein injection (TVI) and renal artery administration (RAA), respectively, with TG-PLA-NPs as the control group. Renal dialysis fluid was regularly collected to determine the drug concentration in the dialysis fluid, map drug concentration-time curves, and calculate AUC ratio in kidneys through the two injection approaches as the renal targeting parameter (RTP), in order to assess the renal targeting property of LMWC-TG-PLA-NPs.</p><p><b>RESULTS</b>The prepared LMWC-TG-PLA-NPs looked smooth and round. Their average diameter, polydispersity index, encapsulation efficiency and drug loading were (207.6 +/- 3.4) nm, (0.078 +/- 0.009)%, (61.83 +/- 2.43)%, and (10.70 +/- 0.37)%, respectively. The pH 7.4 PBS buffer solution containing 20% ethanol showed obvious sustained release behavior. LMWC-TG-PLA-NPs showed a RTP of 71.97%, which was 3.6 times of TG-PLA-NPs of the control group.</p><p><b>CONCLUSION</b>The prepared LMWC-TG-PLA-NPs showed high drug encapsulation efficiency and drug loading, with obvious sustained release characteristics and renal targeting property. LMWC-TG-PLA-NPs are expected to become a new type vector for reducing toxic and side effects of tripterygium glycoside. Meanwhile, a new method is established for assessing renal targeting property with AUC ratio in kidneys after administrated through caudal veins and renal arteries as the renal targeting parameter.</p>

Pharmacokinetics of supersaturable self microemulsion drug delivery system of silybin in rats / 中草药

Objective: To study in vivo pharmacokinetic characteristic of supersaturable self microemulsion drug delivery system (S-SMEDDS) of silybin in rats. Methods: According to the random design, 12 male rats were divided into one control group and one experimental group by six each. SMEDDS of silybin was given to the control group and S-SMEDDS of silybin to the experimental group by both ig administration at dosage of 533 mg/kg, respectively. Blood sampling was conducted by means of an automated blood sampling device (Accusampler) at different time points. After ig administration of S-SMEDDS of silybin to rats, the silybin concentrations in plasma were determined by HPLC and the pharmacokinetic parameters were calculated by non-compartment model of statistical moment analysis. Results: The main pharmacokinetic parameters of the control and experimental groups were as follows: tmax is (1.00 ± 0.40) and (1.50 ± 0.84) h, Cmax is (5.68 ± 0.52) and (16.10 ± 4.06) μg/mL, AUC0→1 is (27.30 ± 3.29) and (82.64 ± 12.36) μg·h·mL-1, respectively. Conclusion: This assessment demonstrates that the oral absorption bioavailability could be substantially improved via the approach: by S-SMEDDS of silybin.