盐酸非索非那定胶囊药物动力学及人体相对生物利用度研究

目的:研究国产盐酸非索非那定胶囊与进口盐酸非索非那定片药物动力学及人体相对生物利用度。方法:20例健康男性志愿者,用随机双交叉试验方法,单剂量口服盐酸非索非那定受试制剂或参比制剂120 mg,采用 HPLC-荧光法测定血浆中非索非那定浓度,进行药物动力学及相对生物利用度分析。结果:单剂量口服受试制剂和参比制剂的 T_(max)分别为(2.55±0.72)h 和(2.60±0.84)h;C_(max)分别为(370.8±84.7)μg·L~(-1)和(354.5±88.3)μg·L~(-1);t_(1/2)分别为(5.34±1.15)h 和(5.62±1.23)h;Cl 分别为(51.0±8.1)L·h 和(53.8±9.4)L·h;V_d分别为(390.6±96.8)L 和(438.4±122.4)L;MRT_(0-t)分别为(6.61±0.82)h 和(6.56±0.87)h,采用梯形法计算,AUC_(0-t)分别为(2290.1±368.1)μg·h·L~(-1)和(2159.5±372.8)μg·h·L~(-1),AUC_(0-∞)分别为(2409.8±389.5)μg·h·L~(-1)和(2290.6±382.8)μg·h·L~(-1)。结论:以 AUC_(0-t)计算,单剂量口服盐酸非索非那定胶囊后,体内相对生物利用度为(107.6±17.3)%。经方差分析和双单侧 t 检验表明2种制剂在人体内具有生物等效性。     

2种洛伐他汀片人体药动学及生物等效性研究

目的:比较2种洛伐他汀片在健康人体内的药代动力学和生物利用度,评价2种制剂的生物等效性。方法:18名男性健康志愿者随机交叉分别单剂量口服山东罗欣药业股份有限公司研制的洛伐他汀片5片(20 mg·片~(-1))或北京万生药业有限责任公司生产的洛伐他汀片5片(20 mg·片~(-1)),采用 HPLC 测定血浆中药物浓度,通过方差分析和双向单侧 t 检验比较2种制剂的 AUC_(0→24)、C_(max)、T_(max)。结果:2种制剂的 T_(max)(h)分别为2.11±0.21和2.11±0.21,C_(max)(ng·mL~(-1))为93.73±17.42和92.67±13.98,t_(1/2)(h)分别为6.75±1.33和6.50±1.09,AUC_(0→24)(ng·mL~(-1)·h~(-1))分别为480.56±55.75和478.24±69.26,AUC_(0→∞)(ng·mL~(-1)·h~(-1))分别为555.33±69.98和543.04±76.25。结论:2种洛伐他汀片生物等效,受试制剂与参比制剂的相对生物利用度为(102.67±6.98)%。     

慢性肾衰患者血液透析时司帕沙星的药物动力学

目的 观察司帕沙星在慢性肾衰患者血液透析时的药物动力学特征.方法 用高效液相色谱法测定透析和非透析住院患者单剂量口服司帕沙星后血清和尿药物浓度,并计算药物动力学参数.结果 经PKNP-N_1药代动力学软件摸拟和计算,司帕沙星的药物动力学符合一级吸收二室开放模型,主要药动学参数:透析时T_(1/2(ka))=(1.25±0.57)h,T_(1/2β)=(11.88±4.13)h,T_(peak)=(4.18±0.78)h,C_(max)=(0.80±0.17)mg·L~(-1),AUC_(0~∞)=(6.90±3.25)mg·h·L~(-1)尿中24h原形药物排除率为(8.98±3.92)%;未透析时T_(1/2(ka))=(1.12±0.42)h,T_(1/2β)=(15．93±5．20)h,T_(peak)=(3.88±0.75)h,C_(max)=(0.69±0.37)mg·L~(-1),AUC_(0~∞)=(10.05±4.13)mg·h·L~(-1),尿中24h原形药物排出率为(10.58±5.64)%.结论 司帕沙星在慢性肾衰患者血液透析时消除加快.     

磷酸川芎嗪胶囊的人体生物等效性研究

目的:评价两种磷酸川芎嗪胶囊的生物等效性。方法:20名健康志愿者单剂量随机交叉口服两种磷酸川芎嗪胶囊100mg,采用HPLC法测定血浆中磷酸川芎嗪浓度;用DAS 2.0生物等效性软件计算主要药物动力学参数和生物等效性。结果:受试制剂和参比制荆其主要药动学参数t_(1/2)分别为(0.82±0.37)和(0.97±0.42)h;C_(max)分别为(2.12±0.62)和(1.96±0.52)mg·L~(-1),t_(max)分别为(0.33±0.09)和(0.36±0.10)h,AUC_(0-1)分别为(1.84±0.38)和(1.75±0.39)mg·h·L~(-1),AUC_(0-∞)分别为(1.86±0.40)和(1.78±0.39)mg·h·L~(-1),经方差分析和双单侧t检验,C_(max),t_(max),AUC_(0-1),AUC_(0-∞)均无统计学差异,受试制剂的相对生物利用度为105.5%。结论:两种磷酸川芎嗪胶囊在健康人体内具有生物等效性。     

富马酸托特罗定在健康中国人体内的药代动力学研究

目的:建立健康人血浆中托特罗定 HPLC—MS/MS 测定法,研究富马酸托特罗定在健康中国人的药物动力学,并与酒石酸托特罗定进行比较。方法:以丁洛地尔为内标,血浆样品碱化后经乙醚-正戊烷(3:1)萃取,经 Hypurity C_(18)柱分离,采用MS/MS 检测器检测。12名健康志愿者(男女各半)以随机交叉方式单剂量口服富马酸托特罗定3.72 mg 或酒石酸托特罗定4mg。另12名志愿者(男女各半)分别口服富马酸托特罗定3.72 mg,每日2次,连续6 d。研究比较不同酸根托特罗定的药物动力学。结果:托特罗定与内标分离度好,内源性杂质不干扰测定,标准方程为 Y=0.1819C-0.004672,r=0.9999。在0.1～20μg·mL~(-1)范围内托特罗定浓度与峰面积比的线性关系良好,定量下限为0.1μg·mL~(-1),回收率为102.4%～108.8%(n=15),日内 RSD 为5.0%～10.6%(n=5);日间 RSD 为9.2%～10.3%(n=15)。单剂量口服富马酸托特罗定3.72 mg 或与酒石酸托特罗定4 mg 后血药浓度时间曲线符合一级吸收一室模型。药代动力学参数 C_(max)(8.2±5.5)μg·L~(-1),(8.4±5.7)μg·L~(-1);T_(max)为(1.8±0.5)h,(1.9±0.5)h;AUC_(0→12)为(45.2±32.3)μg·h·L~(-1),(46.5±34.3)μg·h·L~(-1);AUC_(0→∞)为(55.6±42.5)μg·h·L~(-1),(56.5±42.9)μg·h·L~(-1);T_(1/2)为(3.8±1.7)h,(3.8±1.9)h。与酒石酸盐相比,富马酸托特罗定的相对生物利用度为(97.8±16.6)%。性别间 C_(max)、AUC_(0→12)、AUC_(0→∞)有显著性差异,可能和试验例数较少或志愿者 EM/PM 分型不同有关。多剂量口服富马酸托特罗定3.72 mg 达到稳态后,C_(max)~(ss)为(13.3±5.56)μg·L~(-1);T_(max)~(ss)为(1.7±0.3)h;AUC_(0→12)~(ss)为(68.3±33.6)μg·h·L~(-1);C_(min)~(ss)为(1.8±1.5)μg·L~(-1);C_(av)(5.7±2.8)μg·L~(-1);DF 为2.1±0.6。性别间主要药物动力学参数无显著性差异。结论:HPLC—MS/MS 方法简单,准确度高,灵敏度好,可用于托特罗定在人体内药物动力学研究。单剂量口服富马酸托特罗定3.72 mg 或酒石酸托特罗定4 mg 后体内药动学无显著性差异,酸根的改变没有改变托特罗定在人体内的药动学行为。托特罗定片在健康志愿者体内的药物动力学参数的性别差异可能和试验例数较少或志愿者 EM/PM 分型不同有关,多次给药后体内无明显蓄积现象。     

来氟米特在中国健康志愿者的药代动力学

目的:研究来氟米特在中国健康志愿者的药代动力学.方法:18名健康志愿者随机分为三组,分别单剂量口服来氟米特(20,40,60mg);6名健康志愿者多剂量口服来氟米特20mg/d,连续30d.高效液相色谱法检测来氟米特活性代谢物(A_(771726)).结果:A_(771726)的血药浓度变化符合一级吸收的一房室模型.单剂量口服来氟米特(20,40,60mg)的主要药动学参数为:T_(1 2,ke)(h):211±18,170±24,252±26;T_(max)(h):13±12,13±4,9±5;C_(max)(mg/L):2.0±0.5,5.2±0.6,6.7±1.5;AUC(mg·h·L~(-1)):647±137,1344±191,2555±907.口服来氟米特20mg·d~(-1),连续30d,血药浓度达到稳态水平.平均谷浓度为32.01-39.72mg/L.C_(max),T_(max)和AUC_(0-24)分别为(41.5±2.4)mg/L,(307±75)h和(22099±1234)mg·h·L~(-1).结论:本品口服吸收快,消除慢.口服20mg·d~(-1),连续30d,血药浓度达到稳态水平.在所试剂量范围内,A_(771726)的血药浓度变化符合一级吸收的一房室模型.     

复方盐酸二甲双胍片在健康志愿者体内的药物动力学和生物等效性

目的:研究复方盐酸二甲双胍片在健康志愿者体内的药物动力学和生物等效性。方法:18名男性健康志愿者随机交叉单次口服复方盐酸二甲双胍片(含盐酸二甲双胍1000 mg,格列本脲5 mg,受试制剂)或联合服用盐酸二甲双胍片1 000 mg和格列本脲片5 mg(参比制剂)后,采用HPLC法分别测定盐酸二甲双胍和格列本脲的经时血药浓度,用3P97软件计算其药物动力学参数和相对生物利用度,评价两种制剂的生物等效性。结果:单次口服受试制剂和参比制剂后,盐酸二甲双胍主要药物动力学参数C_(max)分别为(1.60±0.55)μg·ml~(-1)和(1.46±0.46)μg·ml~(-1),t_(max)分别为(2.1±0.7)h和(2.5±0.8)h,t_(1/2)分别为(4.9±1.7)h和(4.3±1.6)h,AUC_(0→24)分别为(10.47±2.89)μg·ml~(-1)·h和(9.22±2.56)μg·ml~(-1)·h,AUC_(0→∞)分别为(10.95±3.13)μ·ml~(-1)·h和(9.53±2.73)μg·ml~(-1)·h,受试制剂的相对生物利用度F_(0→24)为114.8%±17.6%。格列本脲主要药物动力学参数C_(max)分别为(117.70±28.38)μg·L~(-1)和(106.92±33.76)μg·L~(-1),t_(max)分别为(4.1±2.7)h和(3.8±1.8) h,t_(1/2)分别为(7.6±4.1)h和(8.8±3.9)h,AUC_(0→30)分别为(899.97±296.76)μg·L~(-1)·h和(902.64±353.82)μg·L~(-1)·h,AUC_(0→∞)分别为(943.00±290.09)μg·L~(-1)·h和(989.82±399.90)μg·L~(-1)·h,受试制剂的相对生物利用度F_(0→30)为104.91%±28.31%。结论:两制剂两组分的AUC、C_(max)对数值,经F分析、双单侧t检验和(1-2α)%置信区间法统计分析。表明两种制剂具有生物等效性。     

氢溴酸加兰他敏口腔崩解片与普通片在健康人体的生物等效性

目的 研究中国健康志愿者单次口服氢溴酸加兰他敏(可逆性胆碱酯酶抑制剂)口腔崩解片的生物等效性.方法 20名健康志愿者随机分成2组,分别接受单次口服2种国产氢溴酸加兰他敏20 mg;采用液相色谱-串联质谱法测定给药后不同时间点血浆中的氢溴酸加兰他敏浓度,用DAS ver 2.1软件计算其药代动力学参数.结果 氢溴酸加兰他敏的受试制剂与参比制剂主要药代动力学参数:t_(max)分别为(1.06±0.81),(0.85±0.26)h;t_(1/2)分别为(8.39±1.60),(8.22±1.58)h;C_(max)分别为(39.69±8.17),(43.41±11.58)μg·L~(-1);AUC_(0-t)分别为(384.88±101.75),(407.53±101.12)μg·h·L~(-1);AUC_(0-∞)分别为(396.92±105.85),(420.10±103.73)μg·h·L~(-1).氢溴酸加兰他敏的相对生物利用度为(95.5±16.2)%.结论 2种制剂具有生物等效性.     

LC/MS/MS法测定辛伐他汀血浆浓度及其在健康人体内的药物动力学研究

目的:建立人体血浆中辛伐他汀的LC/MS/MS测定方法,并研究辛伐他汀片在男性健康志愿者体内的药物动力学行为,评价其生物利用度和生物等效性。方法:采用两制剂双周期自身对照试验设计。18名男性健康志愿者随机交叉服用单剂量辛伐他汀试验片剂和参比片剂20mg,采用液相色谱-串联质谱(LC/MS/MS)分析方法测定血浆辛伐他汀的浓度。采用DAS2.0程序计算药物动力学参数和相对生物利用度,并进行等效性评价。结果:测定单剂量口服20mg辛伐他汀参比片剂和试验片剂的AUC_((0→24))分别为(14.90±5.86)和(14.37±4.94)ng·h·ml~(-1),AUC_((0→∞))分别为(15.62±6.29)和(14.78±5.02 )ng·h·ml~(-1);C_(max)分别为(4.54±2.11)和(4.00±1.34)ng·ml~(-1);T_(max)分别为(1.75±0.79)和(1.39±0.65)h。以AUC_((0→24))与AUC_((0→∞))计算相对生物利用度分别为(108.0±52.7)%和(106.4±52.5)%。结论:该法准确灵敏,测得的数据可靠,统计分析表明两种制剂生物等效。     

高效液相色谱荧光检测法考察阿昔洛韦片人体生物等效性

目的:10名健康志愿者随机交叉给药,分别单次po 400mg国产阿昔洛韦被试片剂和参比片剂进行人体生物等效性研究.方法:采用高效液相色谱荧光检测法,测定血浆中阿昔洛韦浓度.结果:经3p97药物动力学计算程序处理拟合,符合口服给药-室开放模型,被试片剂与参比片剂的主要药物动力学参数分别为:l_(max)(1.14±0.28)和(1.25±0.37)h,C_(max)(1078.37±192.32)和(108.93±203.31)μg/L,AUC_(o→∞)(4728.07±940.87)和(5012.86±1295.92)μg·h/L,由梯形法计算AUC_(0→t)分别为(4572.14±917.72)和(4780.74±1197.04)μg·h/L,由AUC_(0→(?))计算所得的相对生物利用度为(97.0±10.5)%.主要药物动力学参数经方差分析和双单侧检验两种片剂无显著性差别(P>0.05).结论:两者为生物等效制剂.     

沙丁胺醇气雾剂在健康受试者体内的药代动力学及生物利用度研究

目的研究沙丁胺醇气雾剂在健康受试者体内的药代动力学及其相对于口服水溶液的生物利用度.方法以10名健康男性志愿者为研究对象,采取随机分组、自身对照、开放实验设计,在吸入或口服沙丁胺醇1.2mg后,定时采血,用HPLC方法测定血浆药物浓度,通过PCNONLIN软件进行房室模型拟合,求算药代动力学参数,用非房室模型计算相对生物利用度.结果沙丁胺醇气雾剂的人体内动力学过程符合二室开放模型.两种给药方式的T_max分别为(0.22±0.07)h和(1.8±0.6)h,C_max分别为(3.4±1.1)ng·mL^-1和(3.9±1.4)ng·mL^-1,T_1/2β分别为(4.5±1.5)h和(4.6±1.1)h.AUC_{0-20 min (inhal)}为AUC_{0-20 min (po)} 的7.94倍.相对生物利用度为57.23%.结论所建立的HPLC方法灵敏、专一、准确、精密.沙丁胺醇气雾剂在人体内的吸收过程与口服水溶液有显著差异.     

Relative bioavailability of salbutamol to the lung following inhalation when administration is prolonged

AIMS: Urinary salbutamol post-inhalation has been shown to be an index of lung deposition. The possibility of using the urinary method for prolonged periods of inhalation (such as nebulized therapy) has been evaluated. METHODS: On separate study days volunteers received salbutamol 5 x 100 microg via either oral administration (ORAL), oral with 5 g oral charcoal (ORAL + C), inhaled from a metered dose inhaler (MDI) or MDI plus 5 g oral charcoal (MDI + C). Each dose was separated by 2 min, i.e. administration time of 8 min. Urine samples were provided at 0, 30, 40, 60 and 120 min postdose. Also seven subjects inhaled 5x100 microg doses from the MDI on five separate occasions and provided urine 0-30 min post dose. RESULTS: No salbutamol was detected in urine samples following ORAL + C. The mean (s.d.) amounts of salbutamol excreted in the urine in the first 30 min post ORAL, MDI and MDI + C were 0.42 (0.55), 11.01 (3.77) and 11.60 (3.68) microg, respectively. The ratio of urinary salbutamol following MDI and MDI + C to ORAL in the 0-30 min collection period was 26.2 and 27.8, and between 30 and 40 min postdose was 5.1 and 4.7, respectively. There was no difference between urinary salbutamol over the first 30 min following MDI and MDI + C with a mean ratio (90% confidence interval) of 95.6 (84.0, 107.2). The mean (s.d.) coefficient of variation for the 30 min urinary salbutamol elimination following inhalation of 5 x 100 microg doses from the MDI by seven subjects (on 5 separate study days) was 9.4 (2.3)%. CONCLUSIONS: The 30 min urinary salbutamol method can be used for an inhalation period of up to 8 min to identify the relative bioavailability to the lung. Samples taken after this time period are affected by excretion of the oral absorbed fraction. Most nebulisers deliver their dose within this administration time.     

硫酸沙丁胺醇口腔崩解片人体生物等效性研究

目的 :比较硫酸沙丁胺醇口腔崩解片和普通片的人体生物利用度。方法 :18名健康志愿受试者随机交叉单剂口服硫酸沙丁胺醇口腔崩解片和普通片 ,用高效液相色谱法测定血药浓度 ,以3p97程序计算药动学参数和生物利用度。结果 :硫酸沙丁胺醇口腔崩解片和普通片体内药 -时曲线符合二室模型 ,崩解片和普通片Cmax 分别为 (17 65±6 48)ng/ml和 (16 60±6 21)ng/ml,Tmax 分别为 (1 92±1 18)h和 (2 03±1 17)h ,AUC0～24 分别为 (127 23±32 41)ng/(h·ml)和 (131 42±37 73)ng/(h·ml) ,相对生物利用度为 (99 32±15 58) %。结论 :硫酸沙丁胺醇口腔崩解片与普通片具有生物等效性     

Comparison of the extrapulmonary beta2-adrenoceptor responses and pharmacokinetics of salbutamol given by standard metered dose-inhaler and modified actuator device

1. Ten healthy subjects were randomised to inhale salbutamol via a standard metered-dose inhaler (MDI), or via a modified metered-dose actuator device (MA). Previously published radiolabelled aerosol data had shown that the MA device produced a lower aerosol velocity, reduced oropharyngeal deposition, but with unchanged pulmonary deposition. 2. Dose-response curves (DRC) were constructed with the following cumulative doses of salbutamol: 200 microg, 600 microg (200 microg + 400 microg), 1400 microg (600microg + 800 microg) ad 2600 microg (1400 + 1200 microg). Dose increments were made every 30 min and measurements of extrapulmonary beta2-adrenoceptor responses were performed 20 min after each dose. In addition, plasma salbutamol concentrations were also measured immediately before and for up to 60 min after the last dose. 3. Baseline values were not significantly different between the two study days for any of the measured parameters. 4. Cmax (ng ml(-1)) for plasma salbutamol (as means and 95% CI for difference between MA and MDI) was: 2.0 (0.3-3.7), P = 0.03. Values for t(max) (min), median and range: MA 5 (5-10) vs MDI 5 (5-10); and AUC 0-60, (ng ml(-1) min, mean and 95% CI for difference between MA and MDI): 69 (-5-143), were not significantly different between the two devices. 5. There was a significant (P < 0.01) left shift in the DRC with the MA device compared with the MDI, for hypokalaemic, finger tremor, chronotropic and electrocardiographic (Twave, Q-Tc) responses to salbutamol. Values for the hypokalaemic response (mmol l(-1)) at 2600 microg were (as change from baseline, means and 95% CI for difference between MA and MDI): 0.23 (0.10-0.36). 6. Thus, the MA device produced greater systemic absorption of salbutamol, and associated extrapulmonary beta2-adrenoceptor responses compared with a standard MDI. These results, therefore, suggest that data from radiolabelled aerosol deposition studies may not predict the systemic absorption of inhaled beta2-adrenoceptor agonists.     

固相萃取结合HPLC-MS测定人血浆中奥曲肽的浓度及相对生物利用度固相萃取结合HPLC-MS测定人血浆中奥曲肽的浓度及相对生物利用度

目的建立人血浆中奥曲肽浓度的HPLC-MS测定法，研究国产奥曲肽注射剂的人体生物利用度。方法 血浆样品用HPL 1cc固相萃取小柱萃取，经Waters Xetrra C₁₈ MS分离后测定。18名健康志愿受试者采用随机交叉试验设计，分别im奥曲肽试验制剂和参比制剂200 μg，不同时间点采血，比较两者的生物利用度。结果线性范围0.5～40 μg·L^-1，方法回收率为97.1%～100.5%。日内、日间RSD分别为1.1%～1.6%，2.9%～4.8%。单剂量im奥曲肽200 μg后两种制剂的C_max分别为（19±10） μg·L^-1和（19±11） μg·L^-1，t_max分别为（0.50±0.15） h和（0.52±0.20） h；AUC_0～7h分别为（50±25） h·μg·L^-1和（50±25） h·μg·L^-1，t_1/2分别为(1.5±0.8) h 和(1.5±0.8) h。二者之间均无显著性差异，以进口奥曲肽为参比制剂，国产奥曲肽注射液的相对生物利用度为101%±10%。结论该方法灵敏、准确度高，可用于奥曲肽体内过程研究。两注射剂为生物等效性制剂。     

Relative lung and total systemic bioavailability following inhalation from a metered dose inhaler compared with a metered dose inhaler attached to a large volume plastic spacer and a jet nebuliser

OBJECTIVE: To compare the lung and systemic delivery of salbutamol following inhalation from a metered dose inhaler (MDI), a MDI attached to a spacer (MDI+SP) and a nebuliser (NEB) using a urinary pharmacokinetic method. METHOD: Twelve healthy subjects each provided urine samples at 0, 30 min and pooled up to 24 h after the start of 5 x 100 microg salbutamol inhaled from MDI and MDI + SP and after 2.5 mg was delivered by NEB. Following nebulisation, the amount of salbutamol trapped on an exhalation filter together with that remaining in the apparatus was determined. The amount left in the spacer and that leaving the MDI mouthpiece was also determined. Thus, for all the methods, the amount available for inhalation from each study dose was determined. RESULTS: The mean (+/- SD) 30-min urinary excretion amounts of salbutamol for MDI, MDI+SP and NEB were 12.6+/-3.5, 27.1+/-6.0 and 16.1+/-4.6 microg, respectively. The mean ratios (90% confidence intervals) for MDI+SP compared with MDI and NEB were 230.2 (186.7, 273.8) and 183.0 (146.4, 219.7) (both P values<0.001), respectively, while that between MDI and NEB was 134 (110.4, 159.1) (P < 0.05). The mean (+/-SD) 24-h urinary excretion values for salbutamol and its metabolite were 287.0+/-46.5, 198.1+/-34.7 and 253.4+/-138.3 microg, respectively. Following inhalation a mean of 202.9+/-51.5 microg was left in the spacer. Similarly, after nebulisation 1387.7+/-88.9 microg was left in the nebuliser chamber, 26.3+/-8.0 microg in the mouthpiece and 553.8+/-68.5 microg exhaled. The mean emitted dose from the MDI was 88.4+/-6.1 microg per actuation. When normalised for the amounts available for inhalation, the mean amounts of salbutamol excreted in the urine during the first 30 min were 2.86+/-0.78, 9.15+/-1.69 and 3.06+/-0.70% following MDI, MDI + SP and NEB, respectively. CONCLUSION: Five 100-microg doses inhaled from a metered dose inhaler attached to a spacer delivered more to the lungs and less to the systemic circulation than either the same doses from a metered dose inhaler used alone or five times the dose given via a jet nebuliser. Spacers should be routinely used instead of nebulisers to manage patients unless they are short of breath.     

Oral bioavailability in pigs of a miconazole/Hydroxypropyl-γ-cyclodextrin/ L-tataric acid inclusion complex produced by supercritical carbon dioxide processing

The objective of this study was to determine the pharmacokinetic parameters of miconazole after oral administration of a miconazole/hydroxypropyl-gamma-cyclodextrin(HPgammaCD)/L-tartaric acid inclusion complex produced by supercritical carbon dioxide processing. The pharmacokinetics of the miconazole ternary complex (CPLX), of the corresponding physical mixture (PHYS), and of miconazole alone (MICO) were compared after oral administration. Six mixed-breed pigs received each formulation as a single dose (10 mg miconazole/kg) in a crossover design. Miconazole plasma concentrations were determined by a high-performance liquid chromatography method. Preliminary in vitro dissolution data showed that CPLX exhibits a faster and higher dissolution rate than either PHYS or MICO. Following CPLX oral administration, mean area under the plasma concentration curve (AUC(0-infinity)) for miconazole was 95.0 +/- 55.8 microg/min/mL, with the peak plasma concentration (C(max) 0.59 +/- 0.39 microg/mL) at 19.30 minutes. The AUC(0-infinity) and C(max) values were significantly higher than those after oral administration of PHYS (AUC(0-infinity) 38.5 +/- 12.7 microg/min/mL and C(max) 0.24 +/- 0.08 microg/mL; P < .1) and of MICO (AUC(0-infinity) 24.1 +/- 14.0 microg/min/mL and C(max) 0.1 +/- 0.05 microg/mL; P < .1). There were also significant differences between PHYS and MICO (P < .1). The results of the study indicate that CPLX shows improved dissolution properties and a higher relative oral bioavailability compared with PHYS and MICO.     

Roflumilast, a once-daily oral phosphodiesterase 4 inhibitor, lacks relevant pharmacokinetic interactions with inhaled salbutamol when co-administered in healthy subjects

OBJECTIVE: Roflumilast is an oral, once-daily phosphodiesterase 4 inhibitor under investigation for the treatment of chronic obstructive pulmonary disease and asthma. In clinical practice, the drug is likely to be co-administered with inhaled bronchodilating beta2-adrenoceptor agonists. Therefore, this study investigated the pharmacokinetic characteristics of roflumilast and its pharmacodynamically active metabolite roflumilast N-oxide when co-administered with orally inhaled salbutamol in healthy subjects. METHODS: In this open, randomized clinical study, 12 healthy male subjects received repeated doses of oral roflumilast 500 microg once daily, orally inhaled salbutamol 200 microg 3 times daily, and a combination of both drugs over 7 days according to a 3-period, changeover design with 14 days washout between treatments. RESULTS: Co-administration of roflumilast and salbutamol did not markedly change roflumilast or roflumilast N-oxide disposition. Point estimates (90% confidence intervals) of area under the curve from 0-24 h (AUC 0-24) and maximum plasma concentration in steady state (Cmax,ss) for roflumilast with salbutamol versus roflumilast alone were 1.05 (0.94, 1.17) and 0.97 (0.84, 1.10); the respective point estimates (90% confidence intervals) for AUC 0-24 and Cmax,ss of roflumilast N-oxide were 0.98 (0.91, 1.06) and 0.98 (0.92, 1.03). Roflumilast co-administration did not alter the pharmacokinetics of steady state salbutamol. The respective point estimates (90% confidence intervals) for AUC 0-6 and Cmax,ss of salbutamol with roflumilast versus salbutamol alone were 1.10 (0.99, 1.21), 1.08 (0.91, 1.28). The combination of both drugs was well tolerated. CONCLUSION: There were no relevant pharmacokinetic interactions between roflumilast and salbutamol at therapeutically effective doses.     

Effect of sodium diclofenac on the bioavailability of amoxicillin

The aim of this study was to evaluate the effect of sodium diclofenac on the bioavailability of amoxicillin. In this randomised, crossover study with a 1-week washout period, 20 volunteers received a 2g oral dose of amoxicillin (Amoxil) (Group 1) or a 2g oral dose of amoxicillin with 100 mg of sodium diclofenac (Voltaren) (Group 2). Blood samples were collected at 0, 0.25, 0.5, 1, 1.5, 2, 2.5, 4, 6, 8, 12 and 24h following drug administration. High-performance liquid chromatography with ultraviolet detection was used to quantify plasma amoxicillin concentrations. Bioassay (Micrococcus luteus ATCC 9341) was performed to verify the antimicrobial efficacy of amoxicillin in vitro. The pharmacokinetic parameters area under the plasma concentration-time curve (AUC), maximum plasma concentration observed during the 24-h study period (C(max)) and renal clearance (CL) were analysed by analysis of variance, and time at which C(max) occurred (T(max)) and volume of distribution (VD) were analysed by Wilcoxon test (P<0.05). For Group 1, the mean (+/- standard deviation) AUC(0-24), C(max) and T(max) values were 3391.8+/-1186.7 microg min/mL, 17.3+/-6.5 microg /mL and 121.5+/-20.6 min, respectively; and for Group 2, the values were 2918.4+/-1024.8 microg min/mL, 15.5+/-5.8 microg /mL and 136.5+/-30.0 min, respectively. Lower values of AUC and C(max) were observed for Group 2 (P<0.05). CL of amoxicillin increased (P< 0.05) by 18.5% in Group 2, suggesting that sodium diclofenac may interfere with amoxicillin renal excretion. In conclusion, sodium diclofenac can significantly reduce the bioavailability of amoxicillin.     

Bioavailability and tissular distribution of docetaxel, a P-glycoprotein substrate, are modified by interferon-alpha in rats

Interferon-alpha (IFN-alpha) inhibits intestinal P-glycoprotein (P-gp) expression in rats. In the present study, the effects of repeated pre-treatment with recombinant human INF-alpha (rhIFN-alpha) on oral and intravenous pharmacokinetics of a P-gp substrate, docetaxel (DTX; Taxotere) were investigated in a rat model. The bioavailability and distribution in different organs were also studied. Sprague-Dawley rats were subcutaneously pre-treated with either rhIFN-alpha for 8 days (4MIU kg(-1), once daily) or with pegylated-IFN-alpha (ViraferonPeg; 60 microg kg(-1), Days 1, 4 and 7). The rats were then distributed into sub-groups (n = 5-6) according to the pre-treatment type, and received one dose of [(14)C]DTX (20 mgkg(-1)) either orally or intravenously. Pharmacokinetics studies were then performed over 240 min, at the end of which tissues (intestine, liver, kidneys, lung, heart and brain) were immediately removed for radioactivity quantitation. Non-pegylated and pegylated IFN-alpha both increased DTX oral bioavailability parameters: C(max) (17.0+/-4.0 microg L(-1) (P < 0.02) and 18+/-5.5 microg L(-1) (P < 0.05), respectively, vs 7.4+/-2.5 microg L(-1) for the control) and AUC (0.036+/-0.010 microg h mL(-1) (P < 0.01) and 0.033+/-0.009 microg h mL(-1) (P < 0.01), respectively, versus 0.012+/-0.004 microg h mL(-1) for the control). IFN-alpha also delayed DTX absorption from 60 min in controls to about 95 min and 80 min in non-pegylated and pegylated treated animals, respectively. However, IFN-alpha did not affect intravenous DTX pharmacokinetics and it had a limited effect on tissue distribution at 240 min. [(14)C]DTX was decreased in intestine and enhanced in brain in both pre-treated groups. rhIFN-alpha modified the P-gp-dependent pharmacokinetics of DTX, limited its intestinal efflux and markedly enhanced its oral bioavailability.