Preparation of nanosuspension of quercetin with a miniaturized milling method / 中国中药杂志

The nanosuspension of quercetin (QT-NS) was prepared by a miniaturized milling method, and the process was optimized by Box-Behnken response surface method. Then the accumulative release rate of QT-NS in vitro was determined. The results showed that the optimal process parameters were as follows: ZrO2 4.5 mL, milling speed 690 r•min⁻¹ and milling time 1.5 h; the particle size of QT-NS was (169±5) nm, polydispersity index of 0.204±0.006 and stability index of 0.827±0.014, respectively. There was a little deviation between the theoretically predicted value and the measured value, indicating that this model had a good prediction effect. The accumulative release rate in vitro of QT-NS in 120 min was significantly higher than that of the raw drug and physical mixture. This simple low-cost miniaturization approach could prepare QT-NS successfully, and could provide reference for the formulation of the nanosuspension.

Preparation of isopsoralen loaded nanostructured carrier and its in vitro transdermal permeation characteristics / 中国中药杂志

To increase the permeation and retention of isopsoralen in skin, and improve its bioavailability.Isopsoralen loaded nanostructure liquid carrier (IPRN-NLC) was prepared by high pressure homogenization andoptimized by orthogonal experiment with the encapsulation efficiency, drug loading and average particle size as the evaluation indexes. The in vitro transdermal permeation of IPRN-NLC was evaluated by Franze diffusion cells.The results showed that solid-liquid lipid ratio of optimum IPRN-NLC formulation was 7∶3,drug-lipid ratio of 1∶30, 1% surfactant. Under these conditions, IPRN-NLC had an average encapsulation of （90.25±0.73）%,drug loading of （1.56±0.27）% and an average particle size of (305±1.57) nm.The in vitro transdermal permeation results showed that IPRN-NLC could increase the amount of IPRN permeated though skin, with 3 times of the epidermal retention as compared with IPRN solution. From the results we can know that the IPRN-NLC prepared by high pressure homogenization can improve the permeation andaccumulation of IPRN in the skin, with wide application prospects in the field of transdermal administration.