Simultaneous determination of cardiovascular drugs in dried blood spot by liquid chromatography-tandem mass spectrometry

A dried blood spot (DBS) sampling method was exploited to extract cardiovascular drugs using a small volume of whole blood of human and rodent. Thereafter, an analytical method using liquid chromatography with tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination of 12 cardiovascular drugs. A 6 mm internal diameter disc containing 10 μL of blood was punched from a specifically designed card and analyzed by LC-MS/MS using a gradient elution method with a total run time of 16 min. For sample separation, a universal octadecyl-silica column was used with a flow rate of 0.2 mL/min. The developed method was validated in terms of linearity, accuracy, and precision, which showed satisfactory results. In addition, the matrix effects were closely investigated to confirm the extraction efficiency. Additionally, the stability was tested by storing DBSs at room temperature; the results showed that these drugs were stable for at least 30 days. Accordingly, the proposed LC-MS/MS method is capable to analyze several cardiovascular drugs in a single analysis. It can be applied to therapeutic drug monitoring in patients as well as in the in vivo settings.     

Effects of Hydrogen Peroxide and Ultrasound on Biomass Reduction and Toxin Release in the Cyanobacterium,Microcystis aeruginosa

Cyanobacterial blooms are expected to increase, and the toxins they produce threaten human health and impair ecosystem services. The reduction of the nutrient load of surface waters is the preferred way to prevent these blooms; however, this is not always feasible. Quick curative measures are therefore preferred in some cases. Two of these proposed measures, peroxide and ultrasound, were tested for their efficiency in reducing cyanobacterial biomass and potential release of cyanotoxins. Hereto, laboratory assays with a microcystin (MC)-producing cyanobacterium (Microcystis aeruginosa) were conducted. Peroxide effectively reduced M. aeruginosa biomass when dosed at 4 or 8 mg L⁻¹, but not at 1 and 2 mg L⁻¹. Peroxide dosed at 4 or 8 mg L⁻¹ lowered total MC concentrations by 23%, yet led to a significant release of MCs into the water. Dissolved MC concentrations were nine-times (4 mg L⁻¹) and 12-times (8 mg L⁻¹ H₂O₂) higher than in the control. Cell lysis moreover increased the proportion of the dissolved hydrophobic variants, MC-LW and MC-LF (where L = Leucine, W = tryptophan, F = phenylalanine). Ultrasound treatment with commercial transducers sold for clearing ponds and lakes only caused minimal growth inhibition and some release of MCs into the water. Commercial ultrasound transducers are therefore ineffective at controlling cyanobacteria.     

新型抗结核化合物TBI-166在比格犬体内的生物利用度

目的：建立比格犬血浆中TBI-166的LC-MS/MS测定方法,研究比格犬口服TBI-166的血浆药代动力学特征和生物利用度。方法比格犬血浆样品中加入TBI-166和内标普萘洛尔后经乙腈沉淀蛋白。 HPLC分离采用Symmetry C8（2.1 mm×50 mm,3.5μm）柱,流动相为含0.1%甲酸的乙腈-水,梯度洗脱,流速为0.2 ml/min质谱检测采用电喷雾离子源,正离子选择反应监测（SRM）模式检测m/z 590→478（TBI-166）和m/z 260→183（普萘洛尔,内标）。应用上述LC-MS/MS方法测定比格犬口服TBI-166（3 mg/kg）和静脉注射（0.5 mg/kg）后的血浆药物浓度,用WinNonlin软件计算药代动力学参数和绝对生物利用度。结果比格犬血浆中TBI-166在2～1000 ng/ml浓度范围内线性关系良好,日内和日间精密度<10%、回收率>98.6%、无明显基质效应且血浆样品稳定性好。雌雄比格犬口服TBI-166（3mg/kg）后血药浓度分别于（4.4±3.5）和（1.4±0.5）h达峰,血药峰浓度分别为（122.0±34.6）和（65.4±2.3）ng/ml,AUC（0-t）为（2615.1±1524.4）和（897.2±318.6）h·μg/L。雌雄比格犬静注TBI-166（0.5mg/kg）后t1/2z为（112.9±25.3）和（69.6±35.3）h、CL为（0.3±0.1）和（0.2±0.1）L/（h·kg）、AUC（0-t）为（3222.4±1656.2）和（1798.0±729.2）h·μg/L。雌雄比格犬口服TBI-166生物利用度分别为13.5%和8.3%。结论本研究建立了比格犬血浆中TBI-166的LC-MS/MS测定方法,该方法准确、简便、灵敏。比格犬口服TBI-166后体内消除较慢,具有一定性别差异,生物利用度为8.3%～13.5%。     

液相色谱-串联质谱法测定大鼠血浆中黄体酮的浓度

目的建立测定大鼠血浆中黄体酮的液相色谱-串联质谱(LC-MS/MS)法。方法血浆样品采用液-液萃取法,经正己烷-二氯甲烷-异丙醇(100∶50∶5,V/V/V)提取后,以甲醇-水(75∶25,V/V)为流动相,以Hypersil ODS柱(50 mm×2.1 mm,5μm)为分析柱,采用ESI源以多反应监测(MRM)方式进行正离子检测。用于定量分析的离子反应为m/z 315.4→m/z(97.0+109.2)(黄体酮)和m/z 385.4→m/z 267.4(醋酸甲地孕酮,内标)。结果黄体酮血浆浓度测定方法的线性范围为0.5~200 ng/ml,日内、内间精密度(RSD)均<6.7%,准确度(RE)在±6.2%之间。结论该方法分析时间短、操作简便、灵敏度高、专属性强,适用于黄体酮的药动学研究。     

两种盐酸特拉唑嗪片的人体生物等效性研究

目的 评价单剂量口服国产和进口盐酸特拉唑嗪片的人体生物等效性。 方法 采用单中心、随机、开放、双周期交叉试验设计,21名受试者在不同周期分别空腹口服国产和进口盐酸特拉唑嗪片2 mg,于给药前0 h及给药后60 h内不同时间点采集静脉血4 ml,采用液-质联用(LC-MS/MS)法测定受试者血浆中特拉唑嗪的浓度。 结果 国产和进口盐酸特拉唑嗪片的t_1/2分别为(13.2±2.39)和(12.5±1.93) h;t_max分别为(1.01±0.83)和(1.08±0.69) h;C_max分别为(40.1±10.6)和(37.3±9.57) ng/ml;AUC_0-∞分别为(428±82.1)和(426±85.2) ng·h/ml。国产盐酸特拉唑嗪片的相对生物利用度为(101.2±14.7)%。国产与进口盐酸特拉唑嗪片AUC_0-t和C_max几何均值比的90%置信区间(CI)均落在80%~125%之间。 结论 国产和进口盐酸特拉唑嗪片具有生物等效性。     

Over-the-Counter “Adrenal Support” Supplements Contain Thyroid and Steroid-Based Adrenal Hormones

Objective

To assess whether dietary supplements that are herbal and/or animal-derived products, marketed for enhancing metabolism or promoting energy, “adrenal fatigue,” or “adrenal support,” contain thyroid or steroid hormones.

Structures of Phytosterols and Triterpenoids with Potential Anti-Cancer Activity in Bran of Black Non-Glutinous Rice

Structures of some bioactive phytochemicals in bran extract of the black rice cv. Riceberry that had demonstrated anti-cancer activity in leukemic cell line were investigated. After saponification with potassium hydroxide, separation of the unsaponified fraction by reversed-phase high performance liquid chromatography (HPLC) resulted in four sub-fractions that had a certain degree of anti-proliferation against a mouse leukemic cell line (WEHI-3 cell), this being IC₅₀ at 24 h ranging between 2.80–467.11 μg/mL. Further purification of the bioactive substances contained in these four sub-fractions was performed by normal-phase HPLC. Structural characterization by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) resulted in, overall, the structures of seven phytosterols and four triterpenoids. Four phytosterols, 24-methylene-ergosta-5-en-3β-ol, 24-methylene-ergosta-7-en-3β-ol, fucosterol, and gramisterol, along with three triterpenoids, cycloeucalenol, lupenone, and lupeol, were found in the two sub-fractions that showed strong anti-leukemic cell proliferation (IC₅₀ = 2.80 and 32.89 μg/mL). The other sterols and triterpenoids were campesterol, stigmasterol, β-sitosterol and 24-methylenecycloartanol. Together with the data from in vitro biological analysis, we suggest that gramisterol is a significant anti-cancer lead compound in Riceberry bran extract.     

瑞巴派特分散片的人体药动学及生物等效性

建立了液相色谱-串联质谱法测定健康志愿者口服瑞巴派特分散片(受试制剂)和普通片(参比制剂,膜固思达(R))后的血药浓度,估算两制剂的药动学参数并评价生物等效性.采用随机、开放、双周期交叉试验设计,22名男性健康志愿者单剂量口服受试或参比制剂0.1g后,血样经乙腈直接沉淀蛋白后进行LC-MS/MS分析,利用DAS2.1.1软件计算药动学参数,并进行生物等效性评价.受试和参比制剂在人血浆中瑞巴派特的cmax为(236.9±103.4)和(233.9±105.1) ng/ml,tmax为(2.7±1.1)和(2.9±1.4)h,t1/2为(2.0±0.8)和(2.3±1.5)h,AUC0→12h为(929.0±291.9)和(970.5±353.2) ng·h·ml1.受试制剂的相对生物利用度为(102.6±29.8)％.