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Hao Z.,China Agricultural University | Wang Y.,Qingdao Animal Drugs Technology Development Research Center | Tang S.,China Agricultural University | Wang G.,China Agricultural University | And 4 more authors.
Journal Wuhan University of Technology, Materials Science Edition | Year: 2010

Gelatin microsphere (GMS) was prepared through W/O emulsion chemicalcrossline method. The best formula was selected by examining its appearance, size, drug carrier and drug dissolution rate. The experimental results showed that the optimized gelatin microspheres were spherical ball with smooth surface and had well dispersion. The average size of blank gelatin microspheres was 15.84 μm, while the loaded microspheres'average diameter were 33.10 μm. It was also shown that drug loading of microspheres increased with increasing loading capacity, but drug encapsulation efficiency had a trend of climbing up and then decline. The encapsulation efficiency reached the maximum when the dosage ratio was 2:1. And the results show ceftiofur sodium microspheres have sustained release in the PBS buffer of pH7.4. © 2010 Wuhan University of Technology and Springer-Verlag Berlin Heidelberg.


Hao Z.,China Agricultural University | Hao Z.,Qingdao Agricultural University | Qu B.,Qingdao Agricultural University | Wang Y.,Qingdao Animal Drugs Technology Development Research Center | And 6 more authors.
Drug Development and Industrial Pharmacy | Year: 2011

Background: Ceftiofur is an effective antibiotic against respiratory infections in livestock. However, ceftiofur concentration that is found in lungs after intravenous injection is not effective. Fortunately, ceftiofur-loaded gelatin microsphere (Cef-MS) enjoys advantages of lung-targeting and can achieve an effective concentration. However, no study has been reported on this modality of drug delivery. Objective: We investigated the properties of this delivery modalitylung targeting ceftiofur-Cef-MSs. Methods: We prepared Cef-MS and investigated drug loading, stability and release characteristics in vitro and studied tissue distribution patterns and potential lung injury in mice. Results: Results showed that the average size and span value are 21.26 μm and 1.07, respectively. Drug loading and loading efficiency were 15.31 and 76.55%, respectively. Cef-MSs were stable in light, heat and humidity, except that agglutinative phenomenon was observed in 90% humidity after 10 days. Cef-MS presented a slower in vitro release pattern compared to ceftiofur. Cef-MS mainly concentrates in lungs after intravenous administration. Furthermore, histopathological studies showed that Cef-MS only induces mild and reversible lung injury and is biologically safe. Conclusion: Cef-MS is a promising alternative form with high lung-targeting properties for the treatment of respiratory infections. © 2011 Informa Healthcare USA, Inc.


Hao Z.,Qingdao Agricultural University | Wu H.,China Institute of Veterinary Drugs Control | Hao L.,China Institute of Veterinary Drugs Control | Zhao Y.,Qingdao Animal Drugs Technology Development Research Center | And 3 more authors.
Journal of Applied Polymer Science | Year: 2013

Drug-loaded microspheres prepared from biomacromolecules have received considerable interest. In this article, we report a facile method for preparing ceftiofur-loaded gelatin-based microspheres for controlled release. We investigated the effects of factors, including the rotational speed, concentration of surfactant, concentration of gelatin, and ratio of water to oil (W/O), on the morphologies of gelatin microspheres and obtained the optimized conditions; for a typical average diameter of about 15 μm, these were 1000 rpm, a concentration of span 80 of 2.0%, a gelatin concentration of 20%, and a W/O of 1:20. Gelatin microspheres loaded with ceftiofur, ceftiofur-Na, and ceftiofur-HCl were prepared and characterized by scanning electron microscopy and laser light scattering. In vitro release studies were carefully performed for microspheres prepared with different crosslinker contents, loaded with different drugs, and blended with chitosan. The loaded ceftiofur showed an obviously longer release time compared with pure ceftiofur powder. A higher content of crosslinker led to a longer release time, but when the content reached 5%, the microspheres had a significantly cracked surface. The results also indicate that the blending of a small amount of chitosan could greatly prolong the release time. © 2013 Wiley Periodicals, Inc.


Hao Z.,Qingdao Agricultural University | Wang L.,Qingdao Agricultural University | Xiao K.,Qingdao Agricultural University | Zhao Y.,Qingdao Animal Drugs Technology Development Research Center | And 5 more authors.
Journal of Materials Science: Materials in Medicine | Year: 2013

Drug delivery systems based on polymer microspheres have received considerable attention. Ceftiofur sodium and ceftiofur hydrochloride is widely used for the treatment of bacterial diseases in animals but the delivery in vivo has not been reported. In this paper, we report the synthesis of microspheres from gelatin and PLGA, two kinds of typical natural and artificial materials, for loading ceftiofur and the in vivo investigation of the pharmacokinetics in beagle dogs. By controlling the synthesis parameters, gelatin and PLGA microspheres with diameter between 5 and 35 microns were obtained. Assay procedures based on high performance liquid chromatography were evaluated and confirmed. The dogs were randomly divided into three groups, i.e., control group, gelatin group, and PLGA group and administrated via intravenous injection. Plasma concentrations of ceftiofur over time were measured and analyzed. Results indicate that the main kinetic parameters do not show significant difference for the gelatin group and control group, but the area under the curve, plasma half-life, apparent volume of distribution, and clearance ratio of PLGA group show significant difference from the gelatin group and the control group. The PLGA microspheres show a low area under the curve but long time release. © 2013 Springer Science+Business Media New York.

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