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@#A novel allicin pro-drug tablet containing antacid pellets was developed to realize pH-regulated allicin release and to guarantee allicin yield in stomach environment.Firstly, allicin precursor pellets containing antacid pellet were prepared and artificial gastric juice was used as the medium to determine the yield of the allicin.Then, the total lipid cholesterol (TC), triglyceride cholesterol (TG), high density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) were used as indicators to study the hypolipidemic effect of allicin precursor pellets in rats.The dissolution test showed that in artificial gastric juice, the yield of allicin-containing antacid pellets exceeded 90%.In pharmacodynamic studies, it was found that antacid pellets showed the expected hypolipidemic effect on hyperlipidemia rats compared without antacid pellets.There was a very significant difference in blood lipid levels between the two test groups (P < 0.05).The allicin pro-drug tablets containing antacid pellets can effectively lower blood lipids.
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@#The purpose of this study was to prepare dabigatran etexilate nanoemulsion to improve bioavailability of dabigatran etexilate, a poorly water-soluble drug. The physicochemical properties and the stability of dabigatran etexilate nanoemulsion were investigated. Equilibrium solubility of dabigatran etexilate in commonly used oil materials for nanoemulsion were determined for selection. Then, surfactant and co-surfactant were chosen based upon the plooted pseudo-ternary diagrams. The formulation and preparation process were further optimized with orthogonal design. As a result, the dabigatran etexilate nanoemulsion was formulated based on the system consisting of Oil Acid/Labrafac Lipophile WL1394/Cremophor RH40/Transcutol P/H2O. The dabigatran etexilate nanoemulsion was found to have a mean diameter of(57. 5±0. 2)nm, Zeta potential of -(20. 9±1. 4)mV, and the drug encapsulation efficiency of(85. 2±1. 0)%. Besides, the droplet size, stability constant and drug content of the nanoemulsion was found to have no significant changes in at least 3 months under room temperature. In conclusion, the uniform and stable dabigatran etexilate nanoemulsion with a clear and translucent appearance was obtained after the optimization of formulation and preparation process. Thus nanoemulsion could be a promising way for the improvement of bioavailability of dabigatran etexilate and other poorly water-soluble drugs.
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@#The aim of this study was to prepare albumin nanoparticles by thermal driven self-assembly, and to investigate the formation mechanism, cellular uptake, the kinetics of cellular uptake and intracellular degradation, etc. By measuring the concentrations of thiol, amino and carboxyl groups, the formation mechanism of albumin nanoparticles was revealed. CCK-8 assay was performed to detect the cytotoxicity; inverted fluorescence microscope was used to observe the cellular uptake of the nanoparticles; while the fluorescence resonance energy transfer(FRET)method was applied to investigate the cellular uptake and intracellular degradation kinetics. The drug-loading capacity was investigated using paclitaxel(PTX)as the model drug. The results showed that the albumin nanoparticles produced by thermal driven self-assembly were safe, nontoxic, biodegradable and stabilized by intermolecular disulfide and amide bonds. The drug-loading study indicates that PTX can be highly encapsulated in the nanoparticles. Hence, thermal driven self-assembly method is green and easy to operate, and the albumin nanoparticles can be applied as a new delivery platform for anticancer drugs.
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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. And the in vitro release behaviors of the nanoparticles were studied as well. The size distribution, zeta potential, morphology of DOX-PLGA NPs were characterized by laser light scattering and transmission electron microscopy; encapsulation efficiency and releasing behavior of DOX-PLGA NPs in vitro were investigated by ultraviolet spectrophotometry. The results show that the DOX-PLGA NPs are regularly spherical in shape with the mean size of (189.2 +/- 5.3) nm, and the zeta-potential of the NPs is about (-28.32 +/- 0.52) mV. Drug loading and encapsulation efficiency are estimated to be (73.16 +/- 0.43) % and (1.51 +/- 0.07) %, respectively. The cumulative percentage of the drug released is 90.34%, and the in vitro release behavior made up of initial burst release and sustained-release could be described by the bidirectional kinetic equation. The results indicate that hydrophilic small-molecule drugs could be successfully entrapped into PLGA-NPs. With optimization of the formulation and preparation conditions, we obtained uniform and stable DOX-PLGA NPs with sustained release character in vitro and pH-sensitive property, which could provide the experimental basis for the development of a new anti-tumor sustained-release formulation.
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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. The result showed that Fe3O4 NPs were selectively deposited on the surface of quartz cell. Microcapsules containing Fe3O4 NPs were fabricated by Fe3O4 NPs and PAH alternately self-assembly on calcium carbonate microparticles firstly, then 0.2 molL(-1) EDTA was used to remove the calcium carbonate. Scanning electron microscopy (SEM), Zetasizer and vibrating sample magnetometer (VSM) were used to characterize the microcapsule's morphology, size and magnetic properties. The result revealed that Fe3O4 NPs and PAH were successfully deposited on the surface of CaCO3 microparticles, the microcapsule manifested superparamagnetism, size and saturation magnetization were 4.9 +/- 1.2 microm and 8.94 emu x g(-1), respectively. As a model drug, Rhodamin B isothiocyanate labeled bovine serum albumin (RBITC-BSA) was encapsulated in microcapsule depended on pH sensitive of the microcapsule film. When pH 5.0, drug add in was 2 mg, the encapsulation efficiency was (86.08 +/- 3.36) % and the drug loading was 8.01 +/- 0.30 mg x m(L-1).
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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. Besides the particle size, zeta potential, entrapment efficiency and micromorphology were investigated, CS-PN/SE's precorneal residence properties and miotic effect were especially studied using New Zealand rabbits as the animal model. When CS-PN/SE was administered topically to rabbit eyes, the ocular clearance and the mean resident time (MRT) of pilocarpine nitrate were found to be dramatically improved (P < 0.05) compared with PN/SE and pilocarpine nitrate solution (PNs), since the K(CS-PN/SE) was declined to 0.006 4 +/- 0.000 3 min(-1) while MRT was prolonged up to 155.4 min. Pharmacodynamics results showed that the maximum miosis of CS-PN/SE was as high as 46.3%, while the miotic response lasted 480 min which is 255 min and 105 min longer than that of PNs and PN/SE, respectively. A larger area under the miotic percentage vs time curve (AUC) of CS-PN/SE was exhibited which is 1.6 folds and 1.2 folds as much as that of PNs and PN/SE, respectively (P < 0.05). Therefore, CS-PN/SE could enhance the duration of action and ocular bioavailability by improving the precorneal residence and ocular absorption significantly.
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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. The net positive surface charge increased with increasing amounts of DMAEMA. Confocal images showed fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA) could penetrate into cationic dextran microspheres but not natural dextran microspheres. TT loading efficiency by post-loading was higher compared with by pre-loading. Even though TT is incorporated in the hydrogel network based on electrostatic interaction, still a controlled release can be achieved by varying the initial network density of the microspheres.
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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. Scanning electron microscopy (SEM) was used to characterize the surface of microcapsules. SEM images indicate that the microcapsules and the polyelectrolyte multilayer were deposited on the surface of CaCO3 microparticles. FITC-bovine serum albumin (FITC-BSA, 2 mg) was incorporated in the CaCO3 microparticles by co-precipitation. Fluorescence microscopy was used to observe the fluorescence intensity of microcapsules. The encapsulation efficiency was (34.31 +/- 2.44) %. The drug loading was (43.75 +/- 3.12) mg g(-1).
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Aim: To prepare novel aqueous polymer dispersions with high flexibility for sustained-release coating and investigate their properties. Methods: The aqueous polymer dispersions were synthesized by the emulsion polymerization. The physico-chemical properties and film-forming potential of the dispersions were investigated while the mechanical properties of the formed film and the drug release behavior when atenolol pellets were coated with the aqueous polymer dispersions were evaluated. Results: The prepared aqueous polymer dispersions (methyl methacrylate/ethyl acrylate, 1:2) were found to have proper physico-chemical properties, excellent film-forming capability and satisfying mechanical properties. It could form free film with high flexibility and low viscosity in low temperature even in absence of the plasticizer. Sustained release of atenolol pellets was achieved when the pellets were coated the polymer dispersions. 4-h and 8-h cumulative releases were more than 50% and 80%, respectively. There was no significant difference in release between pellets prior to and post compression of the coated pellets. Conclusion: The resulting aqueous polymer dispersions could be used as sustained-release coating material with high flexibility suitable for tableting.
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Objective The effect of intermittent iron supplementation weekly and twice weekly was studied in children with iron deficiency anemia(IDA). Methods Subjects were 58 children who were randomly divided into two groups. One group received a dosage of 2mg/kg Fe every 3d for 9 weeks. The other group received the same dose Fe once a week for 12 weeks. Results Hemoglobin and serum ferritin increased significantly after treatment in both groups (P ＜0.05), and zinc protoporphyrin decreased significantly (P ＜0. 05). But serum ferritin of both groups was different after 6 weeks of treatment (P ＜0. 01). The side effect of the group supplemented once every 3d was higher than that of the group once a week, but there was no statistically significant difference. Conclusion Iron sup plementation every 3d has a similar effect to once a week for treatment of IDA. The former should be used for the se rious patients for 6 weeks. The later should be used for infants and the patients whose resistance of intestines and stomach are not good.
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This paper reports serum ?_2 microglobiln (?_2M in abbreviation) in 216 normal children of different ages. Urin ?_2M in 60 normal adults; and both in 50 cases of common glomerular disease in children were detected by RIA. The results showed that serum ?_2M is more accurate than BUN in judging the renal function. The elecating serum ?_2M is coincidence with the elevating of diastolic pressure of the sick children. The dynamic observation on delayed cases examination of serum ?_2M and urin ?_2M may be of help in monitoring the pathological changes in glomerular and tubule.