Formulation optimization of emodin nanostructured lipid carriers by Box-Behnken response surface method and in vitro quality evaluation / 中国中药杂志

Emodin nanostructured lipid carriers(ED-NLC) were prepared and their quality was evaluated in vitro. Based on the results of single-factor experiments, the ED-NLC formulation was optimized by Box-Behnken response surface method with the dosages of emodin, isopropyl myristate and poloxamer 188 as factors and the nanoparticle size, encapsulation efficiency and drug loading as evaluation indexes. Then the evaluation was performed on the morphology, size and in vitro release of the nanoparticles prepared by emulsification-ultrasonic dispersion method in line with the optimal formulation, i.e., 3.27 mg emodin, 148.68 mg isopropyl myristate and 173.48 mg poloxamer 188. Under a transmission electron microscope(TEM), ED-NLC were spherical and their particle size distribution was uniform. The particle size of ED-NLC was(97.02±1.55) nm, the polymer dispersion index 0.21±0.01, the zeta potential(-38.96±0.65) mV, the encapsulation efficiency 90.41%±0.56% and the drug loading 1.55%±0.01%. The results of differential scanning calorimeter(DSC) indicated that emodin may be encapsulated into the nanostructured lipid carriers in molecular or amorphous form. In vitro drug release had obvious characteristics of slow release, which accorded with the first-order drug release equation. The fitting model of Box-Behnken response surface methodology was proved accurate and reliable. The optimal formulation-based ED-NLC featured concentrated particle size distribution and high encapsulation efficiency, which laid a foundation for the follow-up study of ED-NLC in vivo.

Preparation and in vitro evaluation of total alkaloids of Strychni Semen-total glucosides of paeony lipid-based cubic liquid crystalline nanoparticles / 中草药

Objective: To prepare total alkaloids of Strychni Semen (TASS) - total glucosides of paeony (TGP) lipid-based cubic liquid crystalline nanoparticles (TASS-TGP LLCN) and investigate its percutaneous absorption behavior. Methods: TASS-TGP LLCN was prepared by precursor injection method, and the encapsulation efficiency (EE) was determined by ultrafiltration centrifugation. The prescription of TASS-TGP LLCN was optimized by uniform design with the encapsulation efficiency as the index, and the basic properties of the optimized TASS-TGP LLCN were evaluated. Meanwhile, Poloxamer 407 (F127) was used as matrix to prepare gel, Franz diffusion method was used to compare the in vitro percutaneous permeability of TASS-TGP LLCN gel with TASS-TGP ordinary gel. Results: The optimal formula of TASS-TGP LLCN was glycerol monooleate (GMO) 1.0 g, F127 0.25 g, dispersed phase 60 mL. The EE of brucine, strychnine and paeoniflorin were all more than 50%, the average particle size was about (245.3 ± 16.4) nm, the pH value was 6.62, and the cubic structure was uniform in size under transmission electron microscope. The cumulate osmotic quantities in 24 h, the permeation rate and the skin retention volume of TASS-TGP LLCN gel were all better than ordinary gel of TASS-TGP. Conclusion: TASS-TGP LLCN has dual effects of promoting permeability and skin reservoir, which has a potential development prospect.

Synthesis and antitumor evaluation of desmosdumotin C derivatives on B-ring / 中国药学杂志

OBJECTIVE: To synthesize desmosdumotin C derivatives on B-ring with antitumor activity. METHODS: The target compounds were synthesized from 2, 4, 6-trihydroxyacetophenone via methylation, O-methylation and aldol reaction. Their antiproliferative activities were tested against six human tumor cell lines. RESULTS: Fourteen target compounds were synthesized, nine of which were new compounds. All of them were characterized using 1H-NMR, 13C-NMR and MS. CONCLUSION: Preliminary pharmacological test showed that all the title compounds except 1i exhibited potent antitumor activities. 1h and 1n were better than desmosdumotin C in vitro. Introducing two fluoro atom on B-ring would benefit its activity against some tumor cells.