Isopropyl myristate molecular gels and drug-loaded transdermal capability / 药学学报

<p><b>AIM</b>To prepare of isopropyl myristate (IPM) molecular gels and investigate of its transdermal capability.</p><p><b>METHODS</b>Microstructure of IPM gels was studied by scanning electron microscope (SEM) and optical microscope (OM). The rheology and thixotropy of IPM gels were investigated by viscosity. Triptolide was used as model drug to investigate its transdermal capability.</p><p><b>RESULTS</b>The microstructure of IPM gels was a three-dimension network formed by the aggregation of Span 60 in IPM, which was rod-like tubular aggregate. It has good rheology and thixotropy. There was a good linear correlation between the accumulative permeated amount per unit area and the time for triptolide-loaded IPM gels. The permeation process agreed with zero order pharmacokinetics. The average permeability through rat skin for triptolide was 19.26 ng x cm(-2) x h(-1), which was 2.92 times of triptolide unguents obtained commercially available.</p><p><b>CONCLUSION</b>Isopropyl myristate molercular gel can be formed by span 60 assemblies. Transdermal capability drug-loaded IPM gels was better than that of triptolide unguents.</p>

Progress in research on triptolide / 中国中药杂志

To further understand triptolide, this paper has introduced the pharmacology, pharmacokinetics, toxicity, the clinic application and semi-synthesis of triptolide on basis of importance and significant contents of reference which have been consulted in the past twenty years. Presently triptolide and Tripterygium wilfordii have been a hot spot of modernization of Chinese traditional medicine. It is very important to develop a new dosage form of high effect and low toxicity by making use of advanced technology according to its characteristics.

Preparation and toxicity of triptolide-loaded poly (D,L-lactic acid) nanoparticles / 药学学报

<p><b>AIM</b>Investigations on reducing the toxicity of triptolide through poly(D, L-lactic acid) nanoparticles as a drug carrier by oral administration to Wistar rats.</p><p><b>METHODS</b>Triptolide-loaded poly (D, L-lactic acid) nanoparticles (TP-PLA-NPs) were prepared by modified spontaneous emulsification solvent diffusion (modified-SESD). The shape of nanoparticles was observed by transmission electron microscope (TEM). The size distribution and mean diameter were measured by laser light scattering technique. The entrapment efficiency and contents of drug loading were determined by RP-HPLC. The physical state of drug loaded in nanopartiles were primarily investigated by X-ray powder diffractometry. TP-PLA-NPs release behavior in vitro was carried out. After oral administration of the nanoparticles to Wistar rats in 15d, the toxicity for liver and kidney were studied by determining aspartate transaminase (AST), alanine transaminase (ALT) and blood urea nitrogen in serum and concentration of protein in urine.</p><p><b>RESULTS</b>The preparation process adapted to the formulation was as follows: the volume ratio of the aqueous and organic phases was 40/15; the surfactant concentration was 1%; the drug concentration was 0.3%; triptolide-PLA was 1:15 (w/w). The mean diameter was 149.7 nm and the polydispersity index was 0. 088 for the nanoparticles prepared by above conditions. The entrapment efficiency and content of drug loading were 74.27% and 1.36%, respectively. The release behavior of drug in vitro showed an initial burst effect, subsequently a slower rate stage. The results indicated that the liver toxicity (P < 0.01) and kidney toxicity (P < 0.05) caused by triptolide could be decreased significantly by nanoparticles carrier.</p><p><b>CONCLUSION</b>PLA-NPs might be used as a new oral carrier for triptolide.</p>

Characterization of Me. PEG-PLA copolymer nanoparticles prepared by modified spontaneous emulsion-solvent evaporation / 药学学报

<p><b>AIM</b>Characterization of poly (D, L-lactic acid)/monomethylether terminated/polyethylene glycol (Me. PEG-PLA) block copolymers nanoparticles.</p><p><b>METHODS</b>Me. PEG-PLA block copolymers were prepared by bulk polymerization. A series of nanoparticles were made from Me. PEG-PLA block copolymer by modified spontaneous emulsion-solvent evaporation technique.</p><p><b>RESULTS AND CONCLUSION</b>The structure of copolymer was performed by means of 1HNMR and FT-IR. The morphological examination of nanoparticles was performed by means of atomic force microscope (AFM). Results indicated that nanoparticles exhibited a smooth spherulite and core-shell structure. The hydrophilic shell is consisted of PEG segments and hydrophobic core is consisted of PLA segments. Zeta potential of nanoparticles was zero and further indicated core-shell structure. The particle size and size distribution of nanoparticles were measured by laser light scattering technique. The effective particle size range was from 70 to 160 nm and showed a normal distribution.</p>