[Formulation and process optimization of doxorubicin-loaded PLGA nanoparticles and its in vitro release].

Doxorubicin-loaded PLGA nanoparticles (DOX-PLGA NPs) was prepared by double emulsion (W/O/W) solvent evaporation method with the biodegradable materials-poly (lactic-co-glycolic acid) (PLGA) used as carrier materials. Single-factor test was used to investigate the influence of the type and ratio of the organic phase, the amount of surfactant, PLGA concentration, the ratio of external water phase and oil phase (W/O), the ratio of doxorubicin and PLGA, ultrasonic time and stirring time on the preparation of nanoparticles. The best formulation and preparation conditions were optimized by orthogonal test based on single-factor test, evaluation indicator as particle size and entrapment efficiency, and the results were analyzed by overall desirability.

A new mathematical equation for the evaluation of the compression behavior of pharmaceutical materials.

A new mathematical equation characterizing the compression of pharmaceutical materials is presented. This equation presumed that the rate of change of the compressible volume of powder with respect to the pressure is proportional to the compressible volume. The new model provided a good fit to several model substances employing non-linear regression techniques.

[Chitosan-coated ophthalmic submicro emulsion for pilocarpine nitrate].

The study is to design chitosan-coated pilocarpine nitrate submicro emulsion (CS-PN/SE) for the development of a novel mucoadhesive submicro emulsion, aiming to prolong the precorneal retention time and improve the ocular absorption. CS-PN/SE was fabricated in two steps: firstly, pilocarpine nitrate submicro emulsion (PN/SE) was prepared by high-speed shear with medium chain triglycerides (MCT) as oil phase and Tween 80 as the main emulsifier, and then incubated with chitosan (CS) acetic solution. The preparation process was optimized by central composite design-response surface methodology.

[Preparation of polyelectrolyte microcapsules containing ferrosoferric oxide nanoparticles].

In this study, polyelectrolyte microcapsules have been fabricated by biocompatible ferrosoferric oxide nanoparticles (Fe3O4 NPs) and poly allyamine hydrochloride (PAH) using layer by layer assembly technique. The Fe3O4 NPs were prepared by chemical co-precipitation, and characterized by transmission electron microscopy (TEM) and infrared spectrum (IR). Quartz cell also was used as a substrate for building multilayer films to evaluate the capability of forming planar film.

[Preparation of cationic dextran microspheres loaded with tetanus toxoid and study on the mechanism of protein loading].

The aim of this study is to prepare cationic biodegradable dextran microspheres loaded with tetanus toxoid (TT) and to investigate the mechanism of protein loading. Positively charged microspheres were prepared by polymerization of hydroxylethyl methacrylate derivatized dextran (dex-HEMA) and dimethyl aminoethyl methacrylate (DMAEMA) in an aqueous two-phase system. The loading of the microspheres with TT was based on electrostatic attraction.

[Preparation of polyelectrolyte microcapsules contained gold nanoparticles].

In this work, polyelectrolyte microcapsules containing gold nanoparticles were prepared via layer by layer assembly. Gold nanoparticles and poly (allyamine hydrochloride) (PAH) were coated on the CaCO3 microparticles. And then EDTA was used to remove the CaCO3 core.

[Ion-sensitive nanoemulsion-in situ gel system for ophthalmic delivery of flurbiprofen axetil].

The aim of the study is to prepare flurbiprofen axetil nanoemulsion-in situ gel system (FBA/NE-ISG) and observe its ocular pharmacokinetics, rheological behavior, TEM images, irritation and cornea retention. Production of nanoemulsion was based on high-speed shear and homogenization process, and then mixed with gellan gum to prepare FBA/NE-ISG. Rheological study showed that FBA/NE-ISG possesses strong gelation capacity and its viscosity and elastic modulus increases by 2 Pa*s and 5 Pa respectively when mixed with artificial tear at the ratio of 40 : 7.

Optimized preparation, characterization and biodistribution in heart of breviscapine lipid emulsion.

Breviscapine is a Traditional Chinese Medicine treating cardiovascular diseases by promoting blood circulation and removing blood stasis. The major active component of breviscapine has low aqueous solubility, poor chemical stability, short biological half-life and rapid elimination rate from the plasma. The use of a lipid emulsion formulation containing breviscapine might improve chemical stability, increase drug loading, exhibit sustained release profile.

Characterization, biodistribution and targeting evaluation of breviscapine lipid emulsions following intravenous injection in mice.

Breviscapine lipid emulsions were prepared by a high speed dispersion-homogenization method with optimal formulation and technological method. The proportion of liposomes in breviscapine lipid emulsions, an important character for determining the behavior of drug in vivo belongs to which carriers, was less than 5%. Loading breviscapine into lipid emulsions did increase the breviscapine concentrations in plasma, retarded the clearance, and exhibited the properties of sustained-release concluded by pharmacokinetic parameters: after bolus administration, the elimination phase (t(1/2(β)) = 99.

Synthesis, self-assembly, and characterization of PEG-coated iron oxide nanoparticles as potential MRI contrast agent.

Aim: Investigated the self-assembly and characterization of novel antifouling polyethylene glycol (PEG)-coated iron oxide nanoparticles as nanoprobes for magnetic resonance imaging (MRI) contrast agent.

Method: Monodisperse oleic acid-coated superparamagnetic iron oxide cores are synthesized by thermal decomposition of iron oleate. The self-assembly behavior between iron oxide cores and PEG-lipid conjugates in water and their characteristics are confirmed by transmission electron microscope, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, and vibrating sample magnetometer.

Identification of a TRAP transporter for malonate transport and its expression regulated by GtrA from Sinorhizobium meliloti.

Sinorhizobium meliloti can live as a saprophyte in soil or as a nitrogen-fixing symbiont inside the root nodule cells of alfalfa and related legumes by utilizing different organic compounds as its carbon source. Here we have identified the matPQMAB operon in S. meliloti 1021.

Characterization and expression analysis of Medicago truncatula ROP GTPase family during the early stage of symbiosis.

ROPs (Rho-related GTPases of plants) are small GTPases that are plant-specific signaling proteins. They act as molecular switches in a variety of developmental processes. In this study, seven cDNA clones coding for ROP GTPases have been isolated in Medicago truncatula, and conserved and divergent domains are identified in these predicted MtROP proteins.

Synthesis of a novel polymer bile salts-(polyethylene glycol)2000-bile salts and its application to the liver-selective targeting of liposomal DDB.

Purpose: The objective of this study was to achieve a sustained and targeted delivery of liposome to the liver, by modifying the phospholipid [phosphatidylcholine (PC)/cholesterol (10 : 1) liposomes with a novel polymer bile salts-(polyethylene glycol)(2000)-bile salts (BP(2)B).

Methods: First, we generated a novel BP(2)B by N,N'-dicyclohexylcarbodiimide/4-dimethylaminopyridine esterification method and confirmed by Fourier transform infraredand (1) H-NMR spectra. Second, we prepared the BP(2)B-modified liposomes (BP(2)BL) that included BP(2)B, and the effect of the weight ratios of BP(2)B/PC on entrapment efficiency was investigated and BP(2)B/PC = 3% (w/w) was determined as the optimum ratio for the 4,4'-dimethoxy-5,6,5',6'-bi (methylenedioxy)-2,2'-bicarbomethoxybiphenyl liposomes.

[A novel pulmonary delivery system--dry powder inhalers].

Dry powder inhalers (DPIs) have received considerable attention because of their propellant-free composition and stability. DPIs include the DPI devices and inhalation powders. The purpose of this review is to address the development of the DPIs, including the mechanisms of absorption, the products, the devices, the preparation technology, and the characteristics.

Preparation, characterization, and biodistribution of breviscapine proliposomes in heart.

Breviscapine proliposomes were prepared by ethanol injection-homogenization-lyophilization method. On contact with 5% glucose, the proliposomes were rapidly converted into a liposomal dispersion, in which a certain amount of breviscapine was entrapped by the liposomes. The entrapment efficiency measured by reverse dialysis method was 77.

[Electrophoresis and fluorospectrophotometry methods to determine the content and entrapment efficiency of siRNA in cationic liposomes].

To develop different methods for determining siRNA content and the entrapment efficiency of siRNA loaded liposomes, SYBR Gold electrophoresis method and Ribogreen fluorospectrophotometry method were used respectively. SYBR Gold electrophoresis method has a good linear relation in a range at 0.2-2.

[Evaluation with compression equations of compression behavior of pellets with different intragranular pore volumes].

Microcrystalline cellulose (MCC), calcium phosphate (DCP)/MCC (4:1, w/w) and lactose (Lac)/MCC (4:1) pellets with different intragranular porosity were prepared in an extrusion-spheronizator and three volume ratios of ethanol/water were used as binder agents to prepare pellets. The compression behaviors of these pellets with different intragranular pore volume were evaluated with the parameters of Kawakita model. The results showed that high pore volume of pellets made up of MCC had the best compressibility and low pore volume of pellets had a poor compactibility.

[Preparation of verapamil hydrochloride core-in-cup tablets with double-pulsatile and multi-phasic release].

To prepare verapamil hydrochloride (VH) core-in-cup tablets with tri-layered tablet and four-layered tablet as core tablets, separately, which can provide biphasic release with double-pulsatile and multi-phasic release, core tablets were prepared by direct compression method, and core-in-cup tablets by dry-compression coated technology. The parameter, time-lag (T(lag)), was used to evaluate the influence of factors, such as the weight of the top cover layer, the amount of hydroxypropylmethylcellulose (HPMC), and the compression load on VH release. With the increase of the weight and HPMC amount of the top cover layer, the first lag time T(lag1) was prolonged.

[Preparation and in vitro corneal retention behavior of novel cationic microemulsion/in situ gel system].

The aim was to prepare a novel ocular cationic microemulsion-in situ gel (CM-ISG) system with vitamin A palmitate (VAP) as model drug, and investigate the corneal retention behavior and corneal irritation of the system. VAP/CM was prepared by a process based on supply of energy, and the before-and-after gelation rheology of VAP/CM-ISG was investigated. In vitro VAP release and gel dissolution of both VAP/CM-ISG and Oculotect Gel was determined.

Maturation of the nodule-specific transcript MsHSF1c in Medicago sativa may involve interallelic trans-splicing.

In nonplant species, many heat-shock transcription factors (HSFs) undergo spatiotemporal-specific alternative splicing. However, little is known about the spatiotemporal-specific splicing of HSFs in plants. Previously, we reported that the alfalfa HSF gene MsHSF1 undergoes multiple alternative splicing events in various tissues.

The GntR-type regulators gtrA and gtrB affect cell growth and nodulation of Sinorhizobium meliloti.

GntR-type transcriptional regulators are involved in the regulation of various biological processes in bacteria, but little is known about their functions in Sinorhizobium meliloti. Here, we identified two GntR-type transcriptional regulator genes, gtrA and gtrB, from S. meliloti strain 1021.

Recombinant human interleukin-2 inhalation powders: preparation and distribution in the alveolus.

The aim of this work was to prepare recombinant human interleukin-2 (rhIL-2) inhalation powders, and the important parameters such as particle size, the remaining ratio of rhIL-2 were also studied. To elucidate the target effect of rhIL-2 inhalation powders, an in situ pharmacokinetic two-compartment model was used to explain their distribution characteristics in lung epithelial lining fluid and alveolar macrophage in the alveolus after the administration of the rhIL-2 inhalation powders in rats.

[Preparation of tablets containing enteric-coated diclofenac sodium pellets].

Fluidized-bed manufactured enteric-coated diclofenac sodium pellets were compressed into tablets. The blend of two aqueous acrylic resins dispersion in different ratios, Eudragit NE30D and Eudragit L30D-55, were used to prepare enteric-coated diclofenac sodium pellets of different particle sizes and coating level. The cushioning pellets with different properties and these enteric-coated pellets were compressed into tablets in different proportions.