人血浆中尼莫地平的毛细管气相色谱电子捕获检测法及药代动力学

目的：建立测定人血浆中尼莫地平的毛细管气相色谱电子捕获检测法,并用本法研究尼莫地平片剂在健康人体内的药代动力学及相对生物利用度。方法：色谱柱为25 m×0.2 mm ID OV-101熔融石英毛细管柱,检测器为⁶³Ni电子捕获检测器。内标为尼群地平,血浆样品在碱性条件下用正己烷—乙酸乙酯(1∶1)提取。结果：浓度在2.0～150.0 ng.ml^-1与峰面积比呈良好线性关系,γ=0.99989。人血浆中尼莫地平的最低检出浓度为0.1 ng.ml^-1,方法重现性好,提取回收率大于80%。10名志愿者随机交叉口服单剂量100 mg二种国产尼莫地平片剂后,以本法测定其体内过程符合一室模型。二种片剂的AUC_0→∞。C_max,T_max均无显著差异。结论：尼莫地平血药浓度测定结果表明两种尼莫地平片剂生物等效,A片剂对B片剂的相对生物利用度为102.0%。     

离子对反相高效液相色谱法测定百草枯血药浓度

目的：建立离子对反相高效液相色谱法测定血浆中百草枯的浓度。方法：采用Discovery C₁₈色谱柱;流动相为乙腈-庚烷磺酸钠溶液（12∶88）;10%三氯醋酸直接沉淀血浆蛋白;流速为1.0 mL·min^-1;检测波长为258 nm。结果：定量下限为0.1 μg·mL^-1,线性范围为0.1～10.0 μg·mL^-1,批内和批间RSD分别为3.77%和10.60%,平均回收率大于89.31%。结论：本法具有灵敏、准确、稳定、操作简便等优点,符合生物样本测定的要求,适用于测定人血浆中百草枯的浓度。     

辅酶Q10注射液正交函数——分光光度测定法

本文报告了用正交函数法直接测定辅酶Q₁₀注射液含量的方法。以无水乙醇为溶剂,选择波长范围为268～292nm,间隔为12nm,用3点求二次正交多项式的P₂值,可消除吐温-80的干扰。辅酶Q₁₀回收率为98.60±0.66%。本法操作简单,准确度和精密度均较满意。     

极谱法研究辅酶Q10与β-环糊精的包结行为

目的研究辅酶Q_{10与β-环糊精(β-CD)的包结行为。方法用极谱法考察主体分子β-CD与电活性客体分子辅酶Q10发生包结反应时，包结物还原波峰电流随时间的变化，峰电位随β-CD浓度的变化，并在自然光照条件下分别考察辅酶Q10和包结物的还原波峰电流随时间的变化。结果在0.1 mol·L^-1 HAc/NaAc (pH 4.7)的乙醇-水(60∶40)介质中，辅酶Q10与β-CD形成1∶1的包结物，测得其包结常数kf为1.26×10⁴ L·mol^-1，包结反应的表观速率常数k为6.64×10^-2 min^-1。并测得辅酶Q10的光降解表观速率常数k为7.77×10^-3 min^-1，辅酶Q10-β-CD包结物的k为3.38×10^-3 min^-1。结论辅酶Q10和β-CD可形成包结物，并在一定程度上提高了辅酶Q10的光稳定性。}     

人血浆中辅酶Q_(10)的HPLC测定法及其动态研究

目的：建立人血浆中辅酶Ｑ１０的高效液相色谱检测法,以测定人体内辅酶Ｑ１０的经时变化过程。方法：血浆经无水乙醇沉淀蛋白后,以正己烷提取,进行高效液相色谱法检测。色谱柱为ＳｐｈｅｒｉｓｏｒｂＣ１８１０μｍ２５ｃｍ×４６ｍｍＩＤ,流动相为无水乙醇—水—冰醋酸（９８∶２∶０７）,检测波长为２７５ｎｍ,内标为辅酶Ｑ９。结果：在０２～４０μｇ·ｍｌ－１浓度范围内峰面积比与浓度呈良好的线性关系,γ＝０９９９８,方法重现性好,提取回收率大于９０％;以本法测定了８名男性健康受试者服用辅酶Ｑ１０制剂前后血浆中辅酶Ｑ１０的浓度经时变化过程。结论：用本法测定人血浆中辅酶Ｑ１０浓度结果满意;人血浆中内源性辅酶Ｑ１０浓度为（７６３３±８６３）ｎｇ·ｍｌ－１,且受饮食及运动量的影响     

血浆中卡托普利及其二硫键代谢物总浓度的测定

为测定血浆中卡托普利及其二硫键代谢物总浓度,以适应临床进行血药浓度监测。用高效液相色谱方法。样品中卡托普利二聚体及卡托普利与氨基酸、血浆蛋白的二硫键结合物采用NaBH₄还原,释放出卡托普利原形,经液—液提取纯化后,以邻苯二甲醛及D-苯丙氨酸进行衍生化。选用反相HPLC法,荧光检测。此法线性范围为5～300ng·ml^{-1,最低检测限为5ng·ml-1。用本法测定了多名高血压病患者血浆中卡托普利及其二硫键代谢物的总含量,结果证明此法灵敏度高。}     

辅酶Q10高产酵母菌SY-3发酵工艺的研究

目的为了获得比较高的辅酶Q₁₀产量,以一株酵母菌SY-3作为辅酶Q₁₀的生产菌,研究不同的发酵条件对辅酶Q₁₀产量的影响。方法用皂化法提取,用高效液相检测。结果与结论蔗糖是较好的碳源,蛋白胨是较好的氮源,通过均匀设计初步确定的发酵培养基为:蔗糖4.2%,蛋白胨2.8%,KH₂PO₄0.13%。接种量2%,500mL三角瓶中装液量40mL,pH值4.0,温度26℃,转速240 r/min,在此发酵条件下,发酵液中菌体生长量达到10g/100mL,辅酶Q₁₀产量达到84.6mg/L。     

HPLC法测定复方吡拉西坦脑蛋白水解物片中维生素B1、B2和B6含量

摘 要 目的:建立HPLC法测定复方吡拉西坦脑蛋白水解物片中维生素B₁、维生素B₂和维生素B₆含量的方法。方法: 采用Insteril ODS-3色谱柱（250 mm×4.6 mm,5 μm）,流动相：0.01 mol·L^-1庚烷磺酸钠（含0.25%三乙胺,用冰醋酸调节pH至3.8)-甲醇（75∶25）,柱温30℃,检测波长为280 nm,流速：1.0 ml·min^-1。结果: 维生素B₁、维生素B₂、维生素B₆分别在3.98～99.40 μg·ml^-1（r=0.999 7）、4.08～101.91μg·ml^-1（r=0.999 9）、2.08～52.00 μg·ml^-1（r=0.999 9）范围内线性关系良好,平均回收率分别为99.18%、99.53%、99.27%,RSD分别为0.60%、0.67%、0.71%(n=9)。结论:本法简便、快速、准确,可用于复方吡拉西坦脑蛋白水解物片中维生素B₁、维生素B₂和维生素B₆的含量测定     

反相高效液相色谱荧光检测法测定血浆及膀胱中阿霉素的浓度

目的 建立测定血浆及膀胱组织中阿霉素含量的反相高效液相色谱法。初步应用于膀胱癌患者膀胱内灌注阿霉素预防膀胱肿瘤术后复发的疗效观察。方法 血浆中样品用二氯甲烷-异丙醇混合液提取,膀胱组织制成匀浆后经二氯甲烷-异丙醇混合液提取,Hypersil ODS柱(4.6 mm×200 mm,10μm)为分析柱,甲醇-0.01 mol·L^-1磷酸二氢钾-冰醋酸(85∶15∶0.5)为流动相,检测波长为E_X^{475 nm}、E_M^{545 nm},以柔红霉素为内标。结果 血浆及膀胱组织中阿霉素的线性范围分别为10～300 ng·ml^-1和0.1～1.0μg·g^-1,日内、日间误差RSD均小于10%,平均回收率分别为104.39%和94.52%。结论 本法测定血浆及膀胱组织中阿霉素含量准确、简便,适用于阿霉素药代动力学的研究。     

HPLC法测定降脂护肝胶囊中绿原酸含量

摘 要 目的:建立测定降脂护肝胶囊中绿原酸含量的高效液相色谱方法。方法: 50%（v/v）甲醇 水水浴回流提取胶囊内容物,高效液相色谱法测定。色谱柱：Symmetry C₁₈(150 mm×3.9 mm, 5 μm),流动相：乙腈-水-醋酸（25∶225∶5）,流速：1.0 ml·min^-1,检测波长：327 nm。结果:绿原酸溶液在在10.6～106.0 μg·ml^-1 范围内与峰面积值具有良好的线性关系(r=0.999 9),平均加样回收率96.72％(RSD=1.36％,n=6)。结论:方法操作简便、快捷,利于完善降脂护肝胶囊的质量标准。     

Application of derivative spectrophotometry for determination of coenzyme Q10 in pharmaceuticals and plasma

The use of derivative spectrophotometry is proposed in this work for determination of coenzyme Q₁₀ in formulations and in human plasma. The spectrophotometric procedure is simpler and less expensive than chromatographic techniques commonly used for the analysis of coenzyme. The active compound can be determined in the range 0.25–10 ppm for standard solutions and pharmaceuticals and 0.05–1.5 ppm in plasma. The proposed method was applied for coenzyme determination in real samples. The results agree well with declared value and with these obtained by HPLC.     

Bioavailability of coenzyme Q<Subscript>10</Subscript> in various pharmaceutical formulations

The bioavailability of coenzyme Q₁₀(CoQ₁₀) in various pharmaceutical formulations (solutions and tablets) containing solubilized CoQ₁₀ in comparison to lipophilic powder of CoQ₁₀ has been studied in rats. It is established that the bioavailability of solubilized CoQ₁₀ in tablets and solution after peroral administration is higher than that of lipophilic CoQ₁₀ powder. The time to reach peak CoQ₁₀ concentrations in plasma was shorter for the solution of the solubilized form. Auxiliary swelling substances in tablets prolong and increase the absorption of CoQ₁₀.     

Enhancement of solubility and dissolution of Coenzyme Q10 using solid dispersion formulation

This study aimed to develop a stable solid dispersion of Coenzyme Q₁₀ (CoQ₁₀) with high aqueous solubility and dissolution rate. Among various carriers screened, poloxamer 407 was most effective to form a superior solid dispersion of CoQ₁₀ having significantly enhanced solubility. Particularly, solid dispersion of CoQ₁₀ with poloxamer 407 in the weight ratio of 1:5 prepared by melting method enhanced the solubility of CoQ₁₀ to the greatest extent. However, it exhibited poor stability and hence Aerosil^® 200 (colloidal silicon dioxide) was incorporated into the solid dispersion as an adsorbent to inhibit the recrystallization process. The solid dispersion of CoQ₁₀, poloxamer 407 and Aerosil^® 200 in the weight ratio of 1:5:6 exhibited improved stability with no significant change in solubility during the 1-month stability test. Moreover, the solid dispersion formulation containing Aerosil^® 200 significantly enhanced the extent of drug release (approx. 75% release) as well as the dissolution rate of CoQ₁₀. In conclusion, the present study has developed the stable solid dispersion formulation of CoQ₁₀ with poloxamer 407 and Aerosil^® 200 for the enhanced solubility and dissolution of CoQ₁₀, which could also offer some additional advantages including ease of preparation, good flowability and cost-effectiveness.     

血浆中去甲地西泮及代谢物奥沙西泮的HPLC测定方法和大鼠口服药代动力学

采用高效液相色谱法测定去甲地西泮(去甲安定)及其代谢产物奥沙西泮。以RP-C₁₈为固定相,乙腈—0.01mol·L^-1醋酸钠(pH3.8,33.3:66.6)为流动相,地西泮为内标物,紫外波长240nm处定量测定。去甲地西泮、奥沙西泮和内标物的保留时间分别为2.8min,4.85min和8.5min;绝对回收率分别为74%,86%和86%。奥沙西泮在35.3～2260ng·ml^-1,去甲地西泮在20～2560ng·ml^-1血浆浓度范围内线性关系良好,r=0.9997和r=0.9998。二药的最低检测浓度分别为10ng·ml、和7ng·ml^-1;日内和日间相对标准偏差(RSD)均分别小于6%和10%(n=5)。多种常用药物对样品的色谱峰无干扰。并用此法研究了大鼠单次口服去甲地西泮的药代动力学。     

Palmitate-induced toxicity is associated with impaired mitochondrial respiration and accelerated oxidative stress in cultured cardiomyocytes: The critical role of coenzyme Q9/10

Impaired mitochondrial function concomitant to enhanced oxidative stress-induced damage are well established mechanisms involved in hyperlipidemia-induced cardiotoxicity. Currently, limited information is available on the direct effect of myocardial lipid overload on endogenous coenzyme Q_9/10 (CoQ_9/10) levels in association with mitochondrial respiration and oxidative stress status. Here, such effects were explored by exposing H9c2 cardiomyocytes to various doses (0.15 to 1 mM) of palmitate for 24 h. The results demonstrated that palmitate doses ≥0.25 mM are enough to impair mitochondrial respiration and cause oxidative stress. Although endogenous CoQ_9/10 levels are enhanced by palmitate doses ≤0.5 mM, this is not enough to counteract oxidative stress, but is sufficient to maintain cell viability of cardiomyocytes. Palmitate doses >0.5 mM caused severe mitochondrial toxicity, including reduction of cell viability. Interestingly, enhancement of CoQ_9/10 levels with the lowest dose of palmitate (0.15 mM) was accompanied by a significantly reduction of CoQ₉ oxidation status, as well as low cytosolic production of reactive oxygen species. From the overall findings, it appears that CoQ_9/10 response may be crucial to improve mitochondrial function in conditions linked to hyperlipidemia-induced insult. Confirmation of such findings in relevant in vivo models remains essential to better understand the cardioprotective effects in association with improving endogenous CoQ_9/10 content.     

Possible prevention from the progression of cardiotoxicity in adriamycin-treated rabbits by coenzyme Q10

The cumulative dose-dependent cardiotoxicity induced by doxorubicin (adriamycin, ADR) and its possible prevention by coenzyme Q₁₀ (CoQ₁₀) were studied in rabbits. In the group that received ADR alone, ADR dose-dependent electrocardiography (ECG) abnormalities and severe myocardial damage on electron microscopic examination were observed. In the group that received ADR + CoQ₁₀, these alterations occurred in lesser degree, and ECG changes seemed to be improved. The results indicated that CoQ₁₀ might prevent the progression of cardiotoxicity in ADR-treated rabbits.     

Preparation and Physicochemical Characterization of Aqueous Dispersions of Coenzyme Q10 Nanoparticles

The present study describes a novel pharmaceutical formulation of coenzyme Q₁₀, viz. submicron-sized dispersions of the substance prepared by emulsification of molten coenzyme Q₁₀ in an aqueous phase. Photon correlation spectroscopy reveals mean diameters of 60 to 300 nm depending on process parameters. Coenzyme Q₁₀ nanoparticles remain stable on storage for more than 30 months. Lipophilic drugs can be incorporated into the nanoparticles demonstrating their potential use as a drug carrier system. Transmission electron micrographs of freeze-fractured replica show spherical particles with an amorphous core. Cryo-electron microscopy reveals the coexistence of small unilamellar vesicles in phospholipid stabilized dispersions. Thermoanalysis and X-ray studies indicate that the dispersed and emulsified coenzyme Q₁₀ does not recrystallize even at 4°C over 30 months. These agree with ¹H NMR data which demonstrate that coenzyme Q₁₀ molecules have a high mobility when formulated as nanoparticles and that colloidally dispersed coenzyme Q₁₀ remains in the state of a supercooled melt. Despite the high melting point of the bulk material, coenzyme Q₁₀ dispersions represent no suspensions but O/W emulsions according to the IUPAC definition (1).     

Coenzyme Q10 attenuates cyanide-activation of the ATP-sensitive K+ channel current in single cardiac myocytes of the guinea-pig

Summary The effect of coenzyme Q₁₀ (CoQ₁₀) on the cyanide (CN^–)-induced ATP-sensitive K⁺ channel current (K_ATP) was examined in single atrial myocytes, using the patch clamp technique. Superfusion of the cells with a CN^–/low glucose bathing solution induced an outward current in the whole-cell clamp condition. Glibenclamide (1 M) abolished this current, indicating that the current was carried through the K_ATP channel. After steady-state activation by CN^–, pinacidil (a K_ATP channel opener, 300 M) failed to further increase the current. In cell-attached patches, CN^–, when applied to the bath, induced bursting openings of an 80 pS channel (the K_ATP channel). In cells preincubated for 30 min in a solution containing CoQ₁₀ (100 g/ml), CN^–-activation of the K_ATP channel was markedly attenuated both at the whole cell and at the single channel level. At the steady-state effect of CN^– in CoQ₁₀-treated cells, pinacidil (300 M) activated the current to the maximum level achieved by CN^– in the control cells. These results suggest that CoQ₁₀ reduces in the CN^–-induced KATP current not by affecting the channel itself but by preventing depletion of intracellular ATP caused by CN^–. Send offprint requests to Y. Kurachi at Mayo Foundation