A high-performance liquid chromatography (HPLC) method has been developed and validated for the determination of dexamethasone palmitate (DXP) in bronchoalveolar fluid lavage samples (BALF). DXP in rat BALFs containin...A high-performance liquid chromatography (HPLC) method has been developed and validated for the determination of dexamethasone palmitate (DXP) in bronchoalveolar fluid lavage samples (BALF). DXP in rat BALFs containing the internal standard (IS), testosterone decanoate (TD), was extracted using a mixture of chloroform and methanol (9:1, v/v). Extracts were then centrifuged, dried and dissolved in acetonitrile. A chromatographic separation based on an isocratic elution was done using acetonitrile and water (85:15, v/v) as a mobile phase at a flow rate of 1.2 mL/min. The graph of the developed method was linear within the tested calibration range of 0.5 - 40 μg/mL. The overall extraction recovery of DXP from BALF samples was 84.3% ± 1.6%. The accuracy (relative error) and precision (coefficient of variation) values were within the pre-defined limits of ≤15% at all concentrations. This methodology has been applied to determine levels of DXP in BALF samples collected from rats treated with DXP large porous particles. The measured concentrations were successfully evaluated using a non-compartment pharmacokinetic model. Since the developed method requires only a microvolume (100 μL) of BALF sample for analysis, it is therefore particularly suitable for the evaluation of drug biodistribution in lung.展开更多
Our results show that in liver microsomes from erythromycin,acetylspiramycin and dexamethsone pretreated rats,the rate of praziquantel( PQT)disappearence was increased as compared with control rat When microsomes fro...Our results show that in liver microsomes from erythromycin,acetylspiramycin and dexamethsone pretreated rats,the rate of praziquantel( PQT)disappearence was increased as compared with control rat When microsomes from erythromycin-treated rats were exposed to PQT in the presence of potassium ferricyanide which broke down the cytochrome P-450 Fe(Ⅱ)-metabolite complexes and restored the functional cytochrome P-450,PQT metabolism was further increased. Acetylspiramycin did not form the complexes, so potassium ferricyanide showed no effect on the PQT metabolism in microsomes from acetylspiramycin-treated rats. Triacetyloleandomycin,a specific inhibitor of cytochrome P-450ⅢAI, inhibited PQT metabolism by 53% in liver microsomes from dexamethasone-treated rats.These results indicate the cytochrome P-450ⅢA seems to be involved in metabolism of PQT in rat liver microsomes.展开更多
目的建立以高效液相色谱-蒸发光散射检测器(HPLC-ELSD)法测定依托红霉素片含量的方法。方法大曹三耀(OSAKA SODA GROUP)CAPCELL PAK C_(18) MGⅡS5色谱柱,0.03%二乙胺-乙腈(30∶70,V/V)为流动相,流速为0.9 mL·min^(-1),进样量10μL...目的建立以高效液相色谱-蒸发光散射检测器(HPLC-ELSD)法测定依托红霉素片含量的方法。方法大曹三耀(OSAKA SODA GROUP)CAPCELL PAK C_(18) MGⅡS5色谱柱,0.03%二乙胺-乙腈(30∶70,V/V)为流动相,流速为0.9 mL·min^(-1),进样量10μL,柱温40℃。ELSD参数:漂移管温度45℃,载气流速3.3 L·min^(-1),增益为6。结果依托红霉素在0.209~1.257 mg·mL^(-1)的浓度范围内线性关系良好(r=0.9991);精密度、稳定性、重复性试验的RSD<1.5%;加标回收率平均值为99.6%;定量限为0.209μg,检测限为0.067μg。结论该方法操作简单、准确灵敏、稳定性好,可用于依托红霉素片的含量测定。展开更多
文摘A high-performance liquid chromatography (HPLC) method has been developed and validated for the determination of dexamethasone palmitate (DXP) in bronchoalveolar fluid lavage samples (BALF). DXP in rat BALFs containing the internal standard (IS), testosterone decanoate (TD), was extracted using a mixture of chloroform and methanol (9:1, v/v). Extracts were then centrifuged, dried and dissolved in acetonitrile. A chromatographic separation based on an isocratic elution was done using acetonitrile and water (85:15, v/v) as a mobile phase at a flow rate of 1.2 mL/min. The graph of the developed method was linear within the tested calibration range of 0.5 - 40 μg/mL. The overall extraction recovery of DXP from BALF samples was 84.3% ± 1.6%. The accuracy (relative error) and precision (coefficient of variation) values were within the pre-defined limits of ≤15% at all concentrations. This methodology has been applied to determine levels of DXP in BALF samples collected from rats treated with DXP large porous particles. The measured concentrations were successfully evaluated using a non-compartment pharmacokinetic model. Since the developed method requires only a microvolume (100 μL) of BALF sample for analysis, it is therefore particularly suitable for the evaluation of drug biodistribution in lung.
文摘Our results show that in liver microsomes from erythromycin,acetylspiramycin and dexamethsone pretreated rats,the rate of praziquantel( PQT)disappearence was increased as compared with control rat When microsomes from erythromycin-treated rats were exposed to PQT in the presence of potassium ferricyanide which broke down the cytochrome P-450 Fe(Ⅱ)-metabolite complexes and restored the functional cytochrome P-450,PQT metabolism was further increased. Acetylspiramycin did not form the complexes, so potassium ferricyanide showed no effect on the PQT metabolism in microsomes from acetylspiramycin-treated rats. Triacetyloleandomycin,a specific inhibitor of cytochrome P-450ⅢAI, inhibited PQT metabolism by 53% in liver microsomes from dexamethasone-treated rats.These results indicate the cytochrome P-450ⅢA seems to be involved in metabolism of PQT in rat liver microsomes.
文摘目的建立以高效液相色谱-蒸发光散射检测器(HPLC-ELSD)法测定依托红霉素片含量的方法。方法大曹三耀(OSAKA SODA GROUP)CAPCELL PAK C_(18) MGⅡS5色谱柱,0.03%二乙胺-乙腈(30∶70,V/V)为流动相,流速为0.9 mL·min^(-1),进样量10μL,柱温40℃。ELSD参数:漂移管温度45℃,载气流速3.3 L·min^(-1),增益为6。结果依托红霉素在0.209~1.257 mg·mL^(-1)的浓度范围内线性关系良好(r=0.9991);精密度、稳定性、重复性试验的RSD<1.5%;加标回收率平均值为99.6%;定量限为0.209μg,检测限为0.067μg。结论该方法操作简单、准确灵敏、稳定性好,可用于依托红霉素片的含量测定。