Effects of loading procedures of magnetic nanoparticles on the structure and physicochemical properties of cisplatin magnetic liposomes.

The effects of different loading procedures of magnetic nanoparticles (MNs) on the structure and physicochemical properties of cisplatin magnetic liposomes were investigated by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, and fluorescence spectroscopy. 1, 2-Dipalmitoyl-sn-glycero-3-Phosphocholine based cisplatin magnetic liposomes were prepared using two different procedures. In procedure I, MNs were combined with phospholipids during film formation; MNs were embedded in a phospholipid bilayer. In procedure II, MNs were mixed with drugs during hydration and MNs were contained in an interior aqueous compartment. The encapsulation efficiency of cisplain and the content of MN in procedure I liposomes were 33.5% ± 3.3% and 2.34 ± 0.09 mg mL(-1), respectively. It indicated that the deliberate MN loading into the liposome structure was not only successful using procedure I, but also superior over procedure II both in cisplatin encapsulation efficiency and MN content, which can promote the magnetic targeting effect of magnetic liposomes during delivering cisplatin.

[Synthesis and spectral characteristic of pharmaceutical dipfluzine hydrochloride-benzoic acid co-crystal].

Pharmaceutical co-crystals can improve the chemical and physical properties of active pharmaceutical ingredient (API), which is new idea and expected to provide new stable structures. Pharmaceutical co-crystals have the potential to be much more useful in pharmaceutical products than salts, solvates or hydrates, polymorphs and stoichiometric solvates (pseudo-polymorphs). In our study, dipfluzine hydrochloride-benzoic acid co-crystal was synthesized by solid co-grinding. The samples were subjected to IR, DSC, XRD, Raman and THz spectral analysis. The results indicated that dipfluzine hydrochloride-benzoic acid complex was new phase compared with the single API and CCF. THz-TDS characterization indicated that hydrogen bond formed between API and CCF, which confirmed the formation of co-crystal.

[Assemble of magnetic nanoparticles into the structure of cisplatin liposome].

Effects of different procedures of magnetic nanoparticles into the liposome structure on the distribution of magnetic particles in the liposome were investigated. Magnetic liposomes with high-encapsulating rate of cisplatin (CDDP) were obtained. Fe3O4 magnetic nanoparticles which was modified by organic functional group on surface was synthesized by an one-step modified hydrothermal method. The CDDP magnetic liposomes were prepared by a film scattering-ultrasonic technique and the concentrations of CDDP in the liposomes were measured by graphite furnace atomic absorbance spectroscopy. Magnetic liposomes with different microstructure were prepared by the two different procedures, where the magnetic particles were combined with phospholipid before the film preparation to form liposome in procedure I, and drug solution and the magnetic particles were mixed before hydrating the lipids film to form liposome in procedure II. The liposome structure was observed by transmission electron microscope (TEM). The CDDP magnetic liposomes were prepared by the optimized method which was selected by orthogonal test. Encapsulation rate of the magnetic particles distributed in the phospholipid bilayer through the procedure I was 34.90%. While liposome, produced by the procedure II technique, contained magnetic particles in the interior aqueous compartment, which encapsulation rate was 28.34%. Encapsulation rates of both I and II were higher than that of conventional liposome. The release profile of all the three different liposomes in vitro fitted with a first-order equation. Because of distribution of magnetic particles in the phospholipid bilayer, the skeleton of phospholipid bilayer was changed. The releasing tl/2 of magnetic liposomes produced by the procedure I technique is 9 h, which is shorter than that of the other two liposomes. Assemble of magnetic nanoparticles into the structure of liposome was succeeded by the procedure I, which showed superiority than by procedure II whatever in CDDP liposome encapsulation efficiency and content of the magnetic particles and would ensure sustained-release character.

[Synthesis and spectral characteristic of Ga-Fe3O4 at room temperature].

Gallium bearing ferrites with different gallium content were synthesized by oxidation of ferrous and gallium ions under alkaline condition and room temperature. The samples were subjected to IR, XRD, Mossbauer spectral analysis and magnetization characterization. The results indicated that the green-rust intermediate phase would be produced during the procedure of Ga-Fe3O4 formation, and the green-rust intermediate phase was converted to ferrites with spinel structure during the drying under hot-N2 atmosphere. With the introduction of gallium into the spinel structure, the interplanar crystal spacing of the spinel structure decreased, as indicated from XRD spectra, and the lattice vibration of M(T)-O-M(o) moved to the high-frequency resulting from IR spectra. A small amount gallium introduction entered the tetrahedral sites preferentially rather than the octahedral sites, and increasing gallium introduction would enhance the occupation of octahedral sites. Furthermore, a small content of gallium in the initial solution could prevent the formation of non-magnetic Fe2O3.

[Preparation and evaluation of sustained-release microsphere of Sanguis Draconis in vitro].

OBJECTIVE: To prepare sustained-release microsphere containing extract of Sanguis Draconis and to measure its dissolution in vitro. METHOD: Sustained-release microsphere was prepared with polylactic acid (PLA) as carriers using the oil-in-water (O/W) emulsion solvent evaporation method. The powder particle's characteristics of sustainded-release microsphere were evaluated comprehensively, and its dissolution characteristics in vitro were studied. RESULT: The microsphere was round and its surface was smooth, drug-loading rate was 21.97% and the entrapment rate was 55.76%, the accumulative release percentage was 76. 71% in 16 hours. CONCLUSION: The sustained release effect of Sanguis Draconis microspheres was formed with potentially wide applications.