Peer reviewed article authored by (Yuangang Zu, Yu Zhang, Xiuhua Zhao, et al). Read article or submit your manuscript for publishing.

In this study, folic-dextran-camptothecin (Fa-DEX-CPT) tumor-targeted nanoparticles were produced with a supercritical antisolvent (SAS) technique by using dimethyl sulfoxide (DMSO) as a solvent and carbon dioxide as an antisolvent. A factorial design was used to reveal the effect of various process parameters on the mean particle size (MPS) and morphology of the particles formed. Under the optimum operation conditions, Fa-DEX-CPT nanoparticles with a MPS of 182.21 nm were obtained. Drug encapsulation efficiency and loading efficiency were 62.13% and 36.12%, respectively. It was found that the concentrations of the camptothecin (CPT) and dextran solution had a major influence upon morphology and shape of the final product. In addition, the samples were characterized by Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) with the purpose of developing a suitable targeted drug delivery system for cancer chemotherapy.

The particle sizes of pharmaceutical substances are important for their bioavailability. Bioavailability can be improved by reducing the particle size of the drug. In this study, artemisinin was micronized by the rapid expansion of supercritical solutions (RESS). The particle size of the unprocessed white needle-like artemisinin particles was 30 to 1200 µm. The optimum micronization conditions are determined as follows: extraction temperature of 62 °C, extraction pressure of 25 MPa, precipitation temperature 45 °C and nozzle diameter of 1000 μm. Under the optimum conditions, micronized artemisinin with a (mean particle size) MPS of 550 nm is obtained. By analysis of variance (ANOVA), extraction temperature and pressure have significant effects on the MPS of the micronized artemisinin. The particle size of micronized artemisinin decreased with increasing extraction temperature and pressure. Moreover, the SEM, LC-MS, FTIR, DSC and XRD allowed the comparison between the crystalline initial state and the micronization particles obtained after the RESS process. The results showed that RESS process has not induced degradation of artemisinin and that processed artemisinin particles have lower crystallinity and melting point. The bulk density of artemisinin was determined before and after RESS process and the obtained results showed that it passes from an initial density of 0.554 to 0.128 g·cm⁻³ after the processing. The decrease in bulk density of the micronized powder can increase the liquidity of drug particles when they are applied for medicinal preparations. These results suggest micronized powder of artemisinin can be of great potential in drug delivery systems.

Introduction: The livertaxis of glycyrrhizic acid-conjugated bovine serum albumin (GL-BSA) has been reported in the literature. Now, in this paper, we describe a novel type of drug-targeted delivery system containing 10-hydroxycamptothecin (HCPT) with liver tumor targeting. Methods: First, GL was coupled to BSA then HCPT was encapsulated in GL-BSA by high-pressure homogenization emulsification. In the experimental design, the influencing variables on particle size and drug loading efficiency were determined to be BSA concentration, volume ratio of water to organic phase, and speed and speed duration of homogenization as well as homogenization pressure and the number of times homogenized at certain pressures. Particle size plays an important role in screening optimal conditions of nanoparticles preparation. Characteristics of 10-hydroxycamptothecin-loaded glycyrrhizic acid-conjugated bovine serum albumin nanoparticles (GL-BSA-HCPT-NPs), such as the drug encapsulation efficiency, drug loading efficiency, and GL-BSA content were studied. In addition, the morphology of the nanoparticles (NPs) and weight loss rate were determined and Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, and thermal analysis performed. Results: The average particle size of the sample NPs prepared under optimal conditions was 157.5 nm and the zeta potential was −22.51 ± 0.78 mV; the drug encapsulation efficiency and drug loading efficiency were 93.7% and 10.9%, respectively. The amount of GL coupling to BSA was 98.26 µg/mg. Through physical property study of the samples, we determined that the HCPT had been successfully wrapped in GL-BSA. In vitro drug-release study showed that the nanoparticles could release the drug slowly and continuously. Hemolysis testing showed the safety of GL-BSA as a novel drug delivery system. The targeting properties of GL-BSA-HCPT-NPs were studied in an in vitro cell uptake study and cell proliferation assay. Cells incubated with GL-BSA-HCPT-NPs and labeled with fluorescein isothiocyanate showed more extensive fluorescence spots and stronger fluorescence intensity than samples without GL conjugation. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to determine the inhibitory rate of the samples. It was found that the inhibitory rate of GL-BSA-HCPT-NPs develops as concentration rises. Further, the inhibitory rate of GL-BSA-HCPT-NPs was higher at the same concentration and had a lower half maximal inhibitory concentration value than the other samples. The half maximal inhibitory concentration values of GL-BSA-HCPT-NPs, BSA-HCPT-NPs, and HCPT sodium were 0.78 ± 0.015, 1.62 ± 0.039, and 7.93 ± 0.255 µg/mL, respectively. Conclusion: The results of this study show GL-BSA-HCPT to be a promising new vehicle for hepatocellular carcinoma-targeting therapy.