Long Keying,Cha Ruitao,Zhang Yapei,Li Juanjuan,Ren Fangping,Jiang Xingyu
Cellulose nanocrystals (CNCs) of excellent mechanical properties, high purity, high aspect ratio, and cost-efficient production have drawn many attentions as a new class of reinforcement nanofillers. We chose CNCs as reinforcement nanofillers, which were incorporated in collagen to prepare CNCs/collagen casings by a traditional extruding method. The effects of CNCs on these casings were investigated. The dispersity and compatibility of CNCs within the collagen are rather good. The presence of CNCs can improve the light transmittance, barrier property, tensile strength, Young’s modulus, and thermostability of the CNCs/collagen casings, where collagen might cross-link with CNCs by electrostatic and hydrogen bonding interaction. When the CNCs content is 4 wt%, the water vapor permeability of CNCs/collagen casing reaches the minimum of 0.18 g·mm/h·m 2 ·KPa. That concentration gave the highest light transmittance, and the mechanical properties were optimal. The development of CNCs/collagen casings represents an important potential to extend shelf life by the prevention of lipid oxidation and water loss of sausages.
Developing a targeted oral delivery system to improve the efficacy of veterinary antibiotics and reduce their consumption and environmental risks is urgent. To achieve the duodenum-targeted release of tilmicosin, the enteric granule containing tilmicosin-loaded solid lipid nanoparticles (TIL-SLNs) was prepared based on its absorption site and transport characteristics. The in vitro release, release mechanisms, stability, palatability, and pharmacokinetics of the optimum enteric granules were studied. The intestine perfusion indicated that the main absorption site of tilmicosin was shifted to duodenum from ileum by TIL-SLNs, while, the absorption of TIL-SLNs in the duodenum was hindered by P-glycoprotein (P-gp). In contrast with TIL-SLNs, the TIL-SLNs could be more effectively delivered to the duodenum in intact form after enteric coating. Its effective permeability coefficient was enhanced when P-gp inhibitors were added. Compared to commercial premix, although the TIL-SLNs did not improve the oral absorption of tilmicosin, the time to reach peak concentration (Tmax) was obviously shortened. After the enteric coating of the granules containing SLNs and P-gp inhibitor of polysorbate-80, the oral absorption of tilmicosin was improved 2.72 fold, and the Tmaxwas shortened by 2 h. The combination of duodenum-targeted release and P-gp inhibitors was an effective method to improve the oral absorption of tilmicosin.Keywords:antimicrobial-resistance;tilmicosin enteric granules;P-glycoprotein;duodenum-targeted release;oral absorption;reduce consumption
危险品化学品经营许可证（带存储）