高效液相色谱法同时测定介孔SiO_2/脂质复合递药系统中紫杉醇、姜黄素的含量

为了建立HPLC同时测定介孔SiO_2/脂质复合递药系统(LMSNs)中紫杉醇(TAX)与姜黄素(CUR)含量的方法。方法:Eclipse XDB-C18柱(150 mm×4.6 mm,5μm),乙腈与0.1%甲酸水溶液以不同比例梯度洗脱,流速1 mL/min,检测波长227 nm,柱温25℃,进样体积5μL。结果:TAX、CUR分别均在1.5~30μg/mL、6~300μg/mL范围内线性良好(TAX低、高浓度范围R~2各为0.999 7、1.000 0,CUR低、高浓度范围R~2各为0.999 9、0.999 9);TAX低、中、高浓度回收率各为(95.60±1.53)%、(98.83±1.02)%、(101.49±0.70)%,CUR为(101.44±0.04)%、(103.10±1.04)%、(103.66±0.47)%(n=3)。表明本方法准确度高、重复性好,可用于同时测定TAX-CUR介孔SiO_2/脂质复合递药系统中两药含量。     

MCM-41型介孔纳米材料对氧氟沙星的负载及体外释放

虽然氧氟沙星抗菌谱广,抗菌作用强,在人医及兽医临床上被广泛地应用,但是其生物半衰期短,给临床用药带来不便。为了开发长效氧氟沙星制剂,本研究以高比表面积、比孔容的MCM-41型介孔二氧化硅纳米材料为载体,制得氧氟沙星纳米药物OFX@MSN。并分别通过扫描电镜、透射电镜,氮气吸附-脱附、傅里叶红外等手段对载药前后的纳米粒结构进行了结构确证,证明氧氟沙星载入到介孔二氧化硅的孔洞中形成平均直径约为100nm的分散球状粒子。体外试验显示氧氟沙星的释放时间可以持续3d之久,从而有效维持平稳的血药治疗浓度,减小注射次数。     

一复方藏兽药体外抗菌活性及药效学实验研究

采用平皿法和液体稀释法对急性支气管炎验方制剂进行体外抗菌试验。以急性支气管炎验方制剂药液灌胃给药测定其对小鼠的无毒剂量,同时测定甲型溶血性链球菌、金黄色葡萄球菌、百日咳杆菌标准株对小鼠的最小致死量(MLD)。通过腹腔注射不同菌株(MLD 0.5mL)感染小鼠,以急性支气管炎验方制剂药液治疗。体外抗菌试验表明,急性支气管炎验方制剂对甲型溶血性链球菌、金黄色葡萄球菌、百日咳杆菌标准株均有不同程度的抑制和杀灭作用。药效学实验表明,该验方制剂对人工感染小鼠有不同程度的保护作用,与对照组比较差异显著。说明该验方可以进行临床治疗试验。本实验为扩大应用范围及成果转化奠定了基础。     

微乳过瘤胃胆碱模型探究及体外效果评定

通过乳化法构建微乳型过瘤胃胆碱模型(W/O-RPC)并进行体外效果评定,包括:W/O-RPC模型的构建及验证,W/O-RPC模型配方的优化,W/O-RPC模型体外效果评定。结果表明,乳化剂比例、油水比对W/O-RPC氯化胆碱保护率影响极显著(P<0.01),当乳化剂比例高于4.00%、油水比≥55时,W/O-RPC氯化胆碱保护率大于90%;利用体外发酵系统并应用响应面分析法对不同配方的W/O-RPC模型进行优化得到各因素对氯化胆碱释放率的影响顺序为油水比>乳化剂比例,所得最佳配方为乳化剂比例11.01%,油水比82;以瑞信RPC为对照,在人工唾液中W/O-RPC的2 h降解率为9.72%,显著高于瑞信RPC(5.46%,P<0.05),W/O-RPC的24 h降解率为13.18%,与瑞信RPC无显著差异(13.67%,P>0.05),体外发酵系统中W/O-RPC的2 h和24 h降解率分别为44.00%和87.55%,均显著高于瑞信RPC(5.09%和26.10%,P<0.05),瘤胃后消化中W/O-RPC的2 h和24 h降解率分别为28.06%和52.11%,均与瑞信RPC差异显著(12.30%和67.84%,P<0.05)。     

In vitro and in vivo evaluation of an in situ forming gel system for sustained delivery of Florfenicol

The objective of this study was to develop an injectable in situ forming gel system based on Poloxamer for sustained release of Florfenicol (FFC). The formulations were prepared containing certain amounts of Poloxamer 407 (P407) and Poloxamer 188 (P188) alone or with hydroxylpropyl methylcellulose (HPMC), sodium carboxymethyl cellulose (CMC‐Na), or polyvinyl pyrrolidone (PVP) as polymer additives. The optimal formulation was chosen according to in vitro parameters (gelation temperature, gelation time, pH value, viscosity, and in vitro release). Then the FFC in vivo pharmacokinetic character of the optimal formulation was investigated in dogs with a single dose of 50 mg/kg b.w. under s.c. injection. In vitro release studies, all formulations containing polymer additives had prolonged release time and decreased initial burst to some extent. The optimal formulation containing 0.15% HPMC showed a best sustained release profile for about 128 h with the lowest initial burst in vitro (<40% in 24 h). In vivo, the 20% FFC in situ forming gel provided prolonged drug release time within the therapeutic range for about 100 h, with stable plasma levels and elimination half‐life (t_1/2λz) nine times higher than the control formulation. In conclusion, in situ forming gel is an attractive alternative for FFC sustained release system.     

Antibacterial activity of supernatants of Lactoccocus lactis,Lactobacillus rhamnosus,Pediococcus pentosaceus and curcumin against Aeromonas hydrophila. In vitro study

Veterinary Research Communications - Secretions of beneficial intestinal bacteria can inhibit the growth and biofilm formation of a wide range of microorganisms. Curcumin has shown broad spectrum...     

In vitro effects of insulin on glucose and lipid metabolism in rat embryos

Glucose is utilized for oxidation and synthesis of various lipids in cultured rat embryos. The present experiment examined the effect of insulin on the incorporation of glucose into lipid fractions in rat embryos in vitro . Embryos at the 2-cell, 8-cell and blastocyst stages were incubated for 5 h in hamster embryo culture medium (HECM)-1 containing ¹⁴C-glucose and 170 nmol/L insulin, or in HECM-1 containing only ¹⁴C-glucose, and the oxidation of glucose in these embryos was examined. In addition, the total lipids of blastocysts were separated by thin layer chromatography and the radioactivity of the separated lipid fractions was measured. Oxidation of glucose was significantly increased after insulin treatment compared with that without insulin treatment in 8-cell embryos and blastocysts ( P  < 0.05), but not in 2-cell embryos. Incorporation of glucose into lipids in blastocysts was significantly lowered by insulin treatment compared with that without insulin treatment ( P  < 0.05). Most of the radioactivity was recovered from triacylglycerols of blastocysts and the remaining radioactivity was found in other neutral lipids and phospholipids. We conclude that insulin accelerates the utilization for oxidation of glucose and inhibits the storage of triacylglycerols in rat blastocysts.     

In vitro culture and synchronous release of Sarcocystis neurona merozoites from host cells

The growth of Sarcocystis neurona, isolate UCD1, in continuous culture was examined in 10 cell lines to identify growth conditions and methods for the preparation of parasites free of gross host cell contamination for molecular studies. The unpredictable, slow release of merozoites in most cell lines prompted development of a method to synchronously release the parasites from infected host cells. The calcium ionophore A23187 at a concentration of 1 microM was found to release intracellular merozoites with a 40 min treatment at 37 degrees C. The release of merozoites en masse from attached host cells allowed for the rapid collection of relatively pure parasites from the culture supernatant. This release of merozoites occurred in five different host cell lines. The ionophore-released parasites were highly infectious for host cells and appeared to be morphologically identical to naturally released merozoites, except that the treated merozoites had an increased number of micronemes when examined by electron microscopy. The ionophore did not enhance the release of sporozoites from sporocysts, but freezing in the presence of 5% DMSO released sporozoites that were infectious to bovine monocytes in in vitro culture.     

In vitro platelet release by rat megakaryocytes: effect of metabolic inhibitors and cytoskeletal disrupting agents

Development of an in vitro visual assay facilitated the study of large numbers of megakaryocytes undergoing proplatelet formation in short-term cultures. Approximately 9% of megakaryocytes formed platelets during a 24-hour period. In the presence of an inhibitor of anaerobic glycolysis (NaF), proplatelet formation was inhibited, whereas inhibitors of respiration (NaCN) did not significantly (P greater than 0.05) decrease proplatelet formation. Presence of the microtubule-disrupting agents colchicine and vincristine sulfate in culture medium inhibited proplatelet formation, whereas the microfilament-disrupting agent cytochalasin B had a less pronounced inhibition.     

复方中药制剂对9种畜禽肠道病原菌的体外抑菌试验

畜禽泻痢性疾病是畜禽常发病,严重制约着养殖业的可持续发展。本试验采用牛津杯法分别测定了复方中药制剂水提液、药典四黄止痢颗粒水提液和西药对照药物复方阿莫西林溶液对9种畜禽肠道病原菌（猪大肠杆菌K88、K99、987P,猪沙门氏菌SM2和鸡大肠杆菌O18、O37、O39,鸡沙门氏菌SM1、SM503）的抑菌试验。结果表明,所有药物对9种供试菌均有不同的抑菌效果,对9种畜禽肠道病原菌抑菌直径大小顺序分别是复方阿莫西林溶液、复方中药制剂和药典四黄止痢颗粒水提液。表明复方中药制剂对畜禽肠道致病菌有良好的抑菌作用,完全可以替代抗生素治疗该类病原菌引起的下痢性疾病。