克拉霉素对Caco-2细胞转运他克莫司的影响及机制研究

目的 探讨克拉霉素对Caco-2细胞转运他克莫司的影响及机制。方法 用化学发光免疫分析法测定他克莫司药物浓度；建立Caco-2细胞单层模型，计算表观渗透系数，比较不同浓度他克莫司在Caco-2细胞单层中转运及不同浓度克拉霉素抑制他克莫司的转运。结果 他克莫司浓度为20，40和80 μg·mL^-1时吸收渗透系数P_appAP-BL分别为（2.47±0.09）×10^-6，（3.91±0.17）×10^-6和（4.49±0.16）×10^-6 cm·s^-1；分泌渗透系数P_appBL-AP分别为（6.05±0.21）×10^-6，（9.86±0.70）×10^-6和（11.75±0.28）×10^-6 cm·s^-1；外流比（apparent permeability ratio，PDR）分别为2.45±0.03，2.52±0.12和2.62±0.11；加入不同浓度的克拉霉素（15，30，60 μg·mL^-1）后，分泌渗透系数显著降低，而吸收系数影响不大，PDR随着克拉霉素浓度增加显著降低。结论 Caco-2细胞外排转运体可能参与了他克莫司的转运，克拉霉素合用他克莫司可显著影响他克莫司的吸收。     

依达拉奉软膏的处方筛选及体外透皮性能研究

目的 考察依达拉奉软膏体外皮肤渗透性,筛选软膏剂最佳处方。方法 以大鼠离体皮肤作为渗透屏障,采用Valin-Chien双室渗透扩散池,以HPLC测定依达拉奉的浓度,考察依达拉奉含量、环糊精的型号和含量以及月桂氮卓酮用量对依达拉奉软膏剂经皮渗透性的影响。结果 软膏剂处方的最佳组合为6.0%依达拉奉,8.0%月桂氮卓酮,3.0%β-环糊精,依达拉奉12 h累积渗透量平均值可达（1 215.88±27.59）μg·cm^-2,平均渗透速率为（103.69±7.39）μg·cm^-2·h^-1,结论 软膏剂具有较好的皮肤渗透特性,有望成为依达拉奉新的给药剂型。     

UPLC-MS/MS测定大鼠血浆中胡蔓藤碱乙和胡蔓藤碱丁及其药动学与生物利用度研究

目的 建立一种检测大鼠血浆中蔓藤碱乙和胡蔓藤碱丁的UPLC-MS/MS法，并研究大鼠口服和舌下静脉给药方式下胡蔓藤碱乙和胡蔓藤碱丁的药动学差异。方法 大鼠分别灌胃和舌下静脉注射蔓藤碱乙和胡蔓藤碱丁，在一定时间内取血，离心获得血清；士的宁为内标，通过UPLC-MS/MS来测定血清中蔓藤碱乙和胡蔓藤碱丁的浓度，绘制药-时曲线，计算药动学参数。结果 经灌胃给药5 mg·kg^–1，胡蔓藤碱乙的t_1/2为(5.7±1.2) h，AUC_(0-t)为(59.6±20.1) ng·h·mL^–1，CL/F为(89.1±30.5) L·h^–1·kg^–1，C_max为(18.3±5.3) ng·mL^–1；经舌下静脉给药1 mg·kg^–1后，胡蔓藤碱乙的t_1/2为(1.5±0.3) h，AUC_(0-t)为(140.2±37.4) ng·h·mL^–1，CL为(7.6±2.3) L·h^–1·kg^–1，C_max为(114.9±36.0) ng·mL^–1。经灌胃给药5 mg·kg^–1，胡蔓藤碱丁的t_1/2为(4.7±4.1) h，AUC_(0-t)为(44.3±5.1) ng·h·mL^–1，CL/F为(100.3±11.7) L·h^–1·kg^–1，C_max为(13.0±4.0) ng·mL^–1；经舌下静脉给药0.1 mg·kg^–1后，胡蔓藤碱丁的t_1/2为(1.1±0.4) h，AUC_(0-t)为(72.9±19.1) ng·h·mL^–1，CL为(1.4±0.4) L·h^-1·kg^–1，C_max为(43.7±6.8) ng·mL^–1。胡蔓藤碱乙的生物利用度为8.5%；胡蔓藤碱丁的生物利用度为1.2%。结论 胡蔓藤碱乙、胡蔓藤碱丁吸收迅速，半衰期较短。     

膜性肾病患者他克莫司血浓度与给药剂量的相关性研究

摘 要 目的： 研究他克莫司治疗膜性肾病的有效血药浓度与给药剂量的相关性。 方法: 41例膜性肾病患者给予他克莫司联合小剂量激素治疗,采用均相酶扩大免疫分析法测定他克莫司全血谷浓度,根据患者24h尿蛋白、血浆白蛋白及肾功能变化进行临床疗效评价,分析他克莫司治疗膜性肾病的疗效与血药浓度及给药剂量的相关性。结果:完全缓解组患者他克莫司血药浓度为（7.47±2.74）ng·ml^-1,给药剂量为（0.047±0.007）mg·kg^-1·d^-1;部分缓解组血药浓度为（5.72±1.19）ng·ml^-1,给药剂量为（0.049±0.008）mg·kg^-1·d^-1;无缓解组血药浓度为（3.30±1.08）ng·ml^-1,给药剂量为（0.052±0.01）mg·kg^-1·d^-1。结论: 他克莫司血药浓度在（5.10～9.32）ng·ml^-1时有较好治疗效果,部分患者血药浓度不随给药剂量的增加而提高。     

白芷香豆素黏胶分散型贴剂的制备及体外经皮渗透研究

目的 制备白芷香豆素黏胶分散型贴剂,考察其离体皮肤渗透性和物理性状,筛选贴剂处方,提高白芷香豆素的透皮吸收速率。方法 将白芷香豆素分散于尤特奇压敏胶中,采用流涎工艺制备黏胶分散型贴剂。用Franz扩散池进行乳猪离体皮肤渗透实验,用HPLC测定欧前胡素的含量,考察了白芷香豆素含量、促渗剂的种类和用量、压敏胶的种类和用量、工艺参数对药物稳态透皮速率和贴剂的物理性状的影响。结果 优选出最佳处方为：药物含量1.0 mg·cm^-2,Eudragit E100 9 mg·cm^-2,油酸0.6 mg·cm^-2;固化时间为40 min,稳态透皮速率达到0.82 μg·cm^-2·h^-1。结论 制得的黏胶分散性白芷香豆素贴剂有较高的经皮渗透速率和较好的物理性状,优选出的处方及工艺稳定、可行。     

LC-MS/MS测定阿齐沙坦及其盐在大鼠血浆中的药动学研究

目的 建立液相色谱-串联质谱法测定大鼠血浆中阿齐沙坦及其盐的浓度并研究其药动学。方法 大鼠血浆样本以乙腈沉淀蛋白后,采用Eclipse Plus C₁₈色谱柱（50 mm×3.0 mm,1.8 μm）;流动相（乙腈：水=60：40）,流速为0.35 mL·min^-1,柱温为40℃;采用Agilent 6430三重四极杆串联质谱仪,离子化方式：电喷雾-正离子（API-ES）;监测方式：MRM;阿齐沙坦监测离子对457.3/233.1,缬沙坦监测离子对436.2/291.4,用作内标。SD大鼠灌胃给予阿齐沙坦1.0 mg·kg^-1及阿齐沙坦盐1.2 mg·kg^-1。结果 阿齐沙坦在5~30 000 ng·mL^-1内线性关系良好;回收率为85%~115%,精密度RSD在±15%内。阿齐沙坦盐大鼠体内主要动力学参数如下：AUC_{（0-24 h）}为（12.9±3.2）μg·mL^-1·h^-1,AUC_（0-∞）为（14.2±4.1）μg·mL^-1·h^-1,C_max为（3.8±0.3）μg·mL^-1,T_1/2为（13.4±0.5）h。阿齐沙坦的主要动力学参数如下：AUC_{（0-24 h）}为（8.1±2.6）μg·mL^-1·h^-1,AUC_（0-∞）为（9.7±3.1）μg·mL^-1·h^-1,C_max为（2.3±0.5）μg·mL^-1,T_1/2为（10.5±0.5）h。结论 本法经方法学验证,适用于大鼠血浆中阿齐沙坦及其盐的浓度测定,可用于阿齐沙坦及其盐大鼠体内药动学研究。     

冰片修饰的姜黄素阳离子脂质体的制备及其脑靶向作用研究

目的 制备冰片修饰的姜黄素阳离子脂质体（curcumin-loaded modifying borneol cationic liposomes，Cur-BCLPs），鼻腔给药后考察其在大鼠体内的药动学行为并对其脑组织分布进行研究。方法 采用乙醇注入法制备Cur-BCLPs；透射电镜观察阳离子脂质体的形态；激光粒度仪考察粒径；超速离心法测定其包封率及载药量；以姜黄素混悬液（curcumin suspension，Cur-Sol）和冰片-姜黄素混悬液（borneol curcumin suspension，BO-Cur-Sol）为对照组，考察大鼠鼻腔给药Cur-BCLPs的体内药动学过程，并测定其在大鼠脑组织的浓度，运用DAS 2.0软件拟合药动学参数。结果 阳离子脂质体外观呈圆形或类圆形，平均粒径为（105.99±2.40）nm，包封率和载药量分别为（81.95±1.03）%和（4.28±0.46）%；体内药动学结果显示，Cur-Sol、BO-Cur-Sol和Cur-BCLPs的半衰期（T_1/2）分别为（4.27±1.53）h，（3.98±0.24）h和（6.01±0.63）h，AUC_0→t分别为（224.38±21.95）μg·h·L^-1，（243.40±12.26）μg·h·L^-1和（562.28±24.30）μg·h·L^-1，清除率分别为（1.82±0.36）L·h^-1·kg^-1，（1.72±0.11）L·h^-1·kg^-1和（0.78±0.03）L·h^-1·kg^-1，滞留时间分别为（4.28±0.23）h，（4.41±0.15）h和（8.09±0.17）h。脑组织分布结果显示，Cur-Sol、BO-Cur-Sol和Cur-BCLPs的AUC_0→t分别为（29.82±1.10）μg·h·g^-1，（35.47±1.75）μg·h·g^-1和（54.06±3.90）μg·h·g^-1，清除率分别为（15.73±0.84）L·h^-1·kg^-1，（13.23±0.52）L·h^-1·kg^-1和（8.52±0.92）L·h^-1·kg^-1。结论 Cur-BCLPs经鼻腔给药后显著提高姜黄素体内和脑组织蓄积量并且延缓消除。     

珍菊降压片在大鼠体内药动学研究

目的 建立同时测定大鼠血浆中芦丁和氢氯噻嗪的LC-MS/MS方法,并研究珍菊降压片在大鼠体内的药动学。方法 采用蛋白质沉淀法处理血浆样品,色谱柱为Pntulips BP-C₁₈柱（2.1 mm×50 mm,5μm）,流动相为乙腈-水梯度洗脱,柱温为30℃;流速为0.45 mL·min^-1。采用电喷雾离子源,选择离子反应监测模式。采用DAS 2.0软件计算药动学参数。结果 方法学验证结果表明内源性杂质不干扰待测物和内标的测定,芦丁和氢氯噻嗪的线性范围分别为5~1 000 ng·mL^-1（r²=0.997 1）和2.5~500 ng·mL^-1（r²=0.995 8）。芦丁和氢氯噻嗪药动学参数：AUC_（0-t）为（107 157.31±38 056.63）,（130 387.28±46 306.69）ng·mL^-1·min^-1;T_1/2z为（108.65±20.95）,（240.86±46.44）min;T_max为（34.25±16.34）,（120.00±0.00）min;C_max为（683.44±254.03）,（368.45±136.95）ng·mL^-1。结论 该方法准确度、精密度、回收率和基质效应均符合生物基质样品测试要求,适用于珍菊降压片在大鼠体内的药动学研究。     

PEG-PLA-α-细辛脑纳米粒经鼻腔、静脉给药后的药动学研究

目的 采用与静脉注射对比的方式,研究聚乙二醇-聚乳酸-α-细辛脑纳米粒（PEG-PLA-α-细辛脑纳米粒）鼻腔给药后在大鼠体内的药物动力学。方法 以大鼠为动物模型,采用血药动力学、脑药动力学及荧光标记法对比研究PEG-PLA-α-细辛脑纳米粒经鼻腔给药与静脉注射后药物/纳米粒在大鼠体内的分布情况。结果 PEG-PLA-α-细辛脑纳米粒静脉注射及鼻腔给药后血浆中的AUC_（0-∞）分别为（11032.4±1 827.1）ng·mL^-1·min及（5 992.9±717.5）ng·mL^-1·min,C_max分别为（421.9±100.2）ng·mL^-1及（171.7±26.3）ng·mL^-1,PEG-PLA-α-细辛脑纳米粒鼻腔给药后的绝对生物利用度F为54.3%。PEG-PLA-α-细辛脑纳米粒静脉注射后α-细辛脑在脑组织中的C_max与鼻腔给药后α-细辛脑在脑组织中的浓度C_max分别为（217.9±29.9）ng·mL^-1及（334.2±62.7）ng·mL^-1,PEG-PLA-α-细辛脑纳米粒静脉注射与鼻腔给药后的AUC_brain/AUC_plasma值分别为1.37和2.85,且两者具有统计学意义。PEG-PLA-α-细辛脑纳米粒鼻腔给药后的药物脑靶向效率及鼻-脑传递百分比分别为208.03%及52.01%。荧光标记法结果显示,PEG-PLA-α-细辛脑纳米粒鼻腔给药后脑靶向性比静脉注射后更强。结论 PEG-PLA-α-细辛脑纳米粒适合于鼻腔给药治疗脑部疾病。     

青蒿琥酯自微乳在大鼠体内的药动学研究

目的 建立大鼠血浆中青蒿琥酯的HPLC-MS/MS测定方法,并研究青蒿琥酯自微乳在大鼠体内的药动学特征。方法 12只SD大鼠随机分为2组,单剂量分别灌胃（50 mg·kg^-1）青蒿琥酯自微乳和青蒿琥酯原料药,以格列吡嗪为内标,用LC-MS/MS测定给药后血浆中的药物浓度,并计算药动学参数。结果 青蒿琥酯血浆样品的线性范围为1.0~1 000.0 ng·mL^-1,回归方程为A=294.74C-439.33（r=0.999 6）,定量下限为1.0 ng·mL^-1。日内、日间变异系数（RSD）均<10%,符合生物样品的分析要求。青蒿琥酯原料药和青蒿琥酯自微乳的药动学参数C_max、t_1/2和AUC_0→t分别为：（87.6±8.80）ng·mL^-1,（1.88±0.33）h和（43.3±1.74）h·ng·mL^-1;（421±41.6）ng·mL^-1,（1.48±0.17）h和（282±17.7）h·ng·mL^-1。其中,C_max和AUC_0→t存在显著性差异（p<0.01）。结论 该方法简便灵敏,可用于血浆中青蒿琥酯的含量测定,经灌胃给药后,与原料药比较,青蒿琥酯自微乳能显著提高生物利用度。     

沙参麦冬汤中3种有效成分血药浓度的UPLC-MS/MS测定及药动学研究

［］ 目的：建立大鼠血浆中甘草苷、花椒毒酚和甲基麦冬黄烷酮A的UPLC-MS/MS测定方法,并探讨大鼠灌胃沙参麦冬汤后其在大鼠体内的药动学过程。方法：以流动相乙腈-0.1%甲酸水溶液,梯度洗脱,流速0.3ml/min;采用ESI源,正负离子同时检测模式扫描,多反应监测模式(MRM)检测各成分血药浓度,并用DAS 3.0 软件计算药动学参数。结果：甘草苷、花椒毒酚和麦冬黄烷酮A分别在4.92-315.00ng.mL_-1、1.44-92.00 ng.mL_-1 和0.35-22.00 ng.mL_-1线性关系良好,平均回收率均大于76.5%,日内、日间RSD 均小于15%。大鼠灌胃沙参麦冬汤提取物后,甘草苷、花椒毒酚和甲基麦冬黄烷酮A的AUC_0-t 分别为(718.23±185.55),(22.52±7.53),和(13.55±6.03)ng.h.mL_-1 ; t_1/2分别为3.61±2.01,6.93±7.78 和3.51±1.92h。结论: 本法方便、快捷,可用于甘草苷、花椒毒素和甲基麦冬黄烷酮A的体内定量分析。     

CYP3A5*3基因多态性与他克莫司血药浓度及临床疗效的相关性研究

目的 探讨CYP3A5*3在中国人群中的分布,明确其对他克莫司稳态谷浓度的影响及临床疗效的相关性。 方法 收集55例慢性肾小球肾炎患者的他克莫司稳态谷浓度,酶免疫放大分析法测定其浓度值,根据TL998A荧光检测仪及试剂盒要求进行样品处理及CYP3A5*3基因型测定。分析CYP3A5*3不同基因型对他克莫司血药浓度及临床疗效的影响。 结果 55例患者,共收集他克莫司稳态谷浓度268份, 5~<10 ng.mL_^-1 与10~20 ng.mL_^-1浓度范围他克莫司的临床有效率(82.0%,82.6%)显著高于5 ng.mL_^-1以下浓度范围(45.5%)(p<0.05),同时5~<10 ng.mL_^-1 与10~20μg.mL_^-1浓度范围他克莫司的临床有效率相近(p＞0.05)。CYP3A5*3三种基因型(GA、GG、AA)患者分布频率均符合Hardy－Weinberg平衡(p＞0.05)。三种基因型患者他克莫司血药谷浓度比较,差异无统计学意义(p＞ 0.05);他克莫司剂量和C/D值比较,差异均有统计学意义(p<0.05)。其中突变纯合子GG患者的他克莫司剂量显著低于突变杂合子GA和野生型AA患者,且突变杂合子GA患者显著低于野生型AA患者;突变纯合子GG患者的他克莫司C/D显著高于突变杂合子GA和野生型AA患者,且突变杂合子GA患者显著高于野生型AA患者。C3435T 基因型不同的患者临床有效率相近(p＞ 0.05)。 结论CYP3A5*3基因多态性对我国肾小球肾炎患者他克莫司血药浓度有显著影响,等位基因G携带者他克莫司C/D值更高,且每日所需剂量更低;但CYP3A5*3基因多态性可能与临床疗效无关。     

栀子-闹羊花配伍对大鼠血浆中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的药动学影响

目的考察栀子与闹羊花配伍对闹羊花中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ药动学的影响。方法建立LC-MS/MS测定大鼠血浆中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的分析方法,并用此方法测定大鼠口服给予闹羊花与栀子配伍液及闹羊花单煎液后大鼠体内的闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的血药浓度,计算其药动学参数并统计分析。结果闹羊花毒素Ⅱ在1～200 ng·mL^–1、闹羊花毒素Ⅲ在1～100 ng·mL^–1内线性关系良好(r>0.999),质控样本精密度均<12%,准确度RSD<20%。栀子配伍闹羊花给药和单独给药后体内闹羊花毒素Ⅱ的AUC_0–t分别为(260.44±51.67)和(213.39±59.03) h·ng·mL^–1,闹羊花毒素Ⅲ的AUC_0–t分别为(60.97±22.78)和(22.38±5.55)h·ng·mL^–1。与闹羊花单煎给药相比,栀子与闹羊花配伍给药后闹羊花毒素Ⅱ的T_1/2和MRT₍(0–t))显著升高,闹羊...     

Variability of morphine disposition during long-term subcutaneous infusion in terminally ill cancer patients

Objective: To study the plasma concentrations of morphine and its glucuronides to assess the intra- and interindividual variability of the disposition of morphine administered by subcutaneous infusion in cancer patients. Methods: Blood samples were taken repeatedly in eight patients with severe cancer pain who were being treated with morphine (60–3000 mg per day) via chronic (8–160 days) subcutaneous infusion. Venous blood samples were collected at least weekly and, when possible, on 3 consecutive days after dose adaptation or any other major change in the patients' treatment. Concentrations of morphine and its glucuronides in plasma were measured after solid-phase extraction using a validated high-performance liquid chromatography assay. The stability of the morphine solutions was determined by repeated measurement of the concentrations of morphine and its degradation products in the solutions. Results: The morphine concentration in the infusion solutions remained unchanged during storage and infusion. The plasma concentrations of morphine and its glucuronides were within the ranges reported in the literature. There was, as expected, a large interindividual variability: from patient to patient, the mean of the normalised plasma concentrations ranged from 0.3 ng · ml⁻¹ · mg⁻¹ to 0.8 ng · ml⁻¹ · mg⁻¹ for morphine, from 1.0 ng · ml⁻¹ · mg⁻¹ to 3.1 ng · ml⁻¹ · mg⁻¹ for morphine-6-glucuronide and from 6.8 ng · ml⁻¹ · mg⁻¹ to 24.3 ng · ml⁻¹ · mg⁻¹ for morphine-3-glucuronide. Intraindividual variability was also important. The residual standard deviation of the mean normalised plasma concentrations calculated for each patient ranged from 26% to 56% for morphine, from 20% to 51% for morphine-6-glucuronide and from 20% to 49% for morphine-3-glucuronide. The normalised plasma concentrations of morphine and its glucuronides did not increase with dose or time, and no explanation for the pronounced pharmacokinetic intraindividual variability was found. Conclusion: During subcutaneous infusion of morphine, there is a large intra- and interindividual variability of the morphine disposition which could be of clinical relevance. Received: 5 August 1997 / Accepted in revised form: 8 October 1997     

氟伏沙明和CYP1A2*1F基因多态性对血清奥氮平浓度的影响

目的研究氟伏沙明与细胞色素P450酶1A2(cytochromeP4501A2,CYP1A2)基因*1F位点多态性对精神分裂症患者血清奥氮平浓度的影响。方法入组精神分裂症患者单用奥氮平者(奥氮平组)92例以及奥氮平联用氟伏沙明者(联合组)103例,采集血液,测定CYP1A2*1F基因型以及血清奥氮平浓度,比较2组以及CYP1A2*1F各个基因型间的血清奥氮平浓度差异。结果奥氮平组血清奥氮平浓度(3.39±2.70)mg·L-1·mg-1显著低于联合组(5.14±3.06)mg·L-1·mg-1(t=4.23,P=0.000)。AA型血清奥氮平浓度比CC型低[奥氮平组:(2.46±1.64)mg·L-1·mg-1 vs(4.42±2.88)mg·L-1·mg-1,P<0.05;联合组:(4.06±2.65)mg·L-1·mg-1 vs(6.86±3.25)mg·L-1·mg-1,P<0.01],但是CA型与CC型的差异无统计学显著意义。结论氟伏沙明可升高血清奥氮平浓度;不同基因型个体,血清奥氮平浓度不同;应根据氟伏沙明使用情况和CYP1A2*1F基因型个体化给药。     

1例少年肾移植患者环孢素的药动学分析及个体化给药

本文介绍1例少年肾移植患者术后按常规剂量口服环孢素A后血药浓度监测谷值偏低，根据患者的药代动力学参数及肝肾功能状态。应用微机软件制订个体给药方案，取得了满意的效果。     

他克莫司阳离子微乳凝胶的兔眼刺激性研究及房水药动学研究

目的 研究他克莫司阳离子微乳凝胶对兔眼的刺激性及房水药动学。方法 通过HE染色处理的兔眼组织病理切片观察该制剂的眼部刺激性。采用角膜穿刺术抽取兔眼房水,通过液相色谱-质谱联用仪进行房水药动学研究。结果 他克莫司阳离子微乳凝胶对兔眼无明显刺激性,其房水药动学参数AUC为(128.34±13.09)ng·h/ml,是他克莫司阳离子纳米乳AUC(113.61±12.36)ng·h/ml的1.13倍,是市售他克莫司滴眼液Talymus^?AUC(68.25±10.82) ng·h/ml的1.88倍。结论 他克莫司阳离子微乳凝胶眼部刺激性小、滞留时间长且生物利用度高,具有较好的临床应用前景。     

Influence of sonophoresis and chemical penetration enhancers on percutaneous transport of penbutolol sulfate

The effect of ultrasound and chemical penetration enhancers on transcutaneous flux of penbutolol sulfate across split-thickness porcine skin was investigated. Penbutolol sulfate is a potent, noncardioselective beta-blocker, which is used for the management of hypertension. The drug is one of the most lipid soluble of the β-adrenoceptor antagonists used clinically. It has an n-octanol/pH 7.4 buffer partition coefficient of 179 compared to a value of 22 for propranolol. The amount of penbutolol sulfate transported across the skin is low. In this project, we studied the effect of sonophoresis and chemical penetration enhancers on transdermal delivery of penbutolol sulfate. Low-frequency sonophoresis at a frequency of 20?kHz increased transcutaneous flux of penbutolol sulfate by 3.5-fold (27.37?±?μg?cm^?2?h^?1) compared to passive delivery (7.82?±?1.72?μg?cm^?2?h^?1). We also investigated the effect of 50% ethanol, 1% limonene and 2% isopropyl myristate (IPM) on transcutaneous permeation of penbutolol sulfate. IPM, ethanol and limonene at the concentration of 1%, 50% and 2%, respectively, increased the steady-state flux values of penbutolol sulfate 2.2- (17.07?±?3.24?μg?cm^?2?h^?1), 2.6?- (19.40?±?6.40?μg?cm^?2?h^?1) and 3.4-times (26.38?±?5.01?μg?cm^?2?h^?1) compared to passive delivery (7.76?±?2.9?μg?cm^?2?h^?1). The results demonstrate that although there were slight increases in flux values, ultrasound, ethanol, limonene and IPM did not significantly enhance the transdermal delivery of penbutolol sulfate. Future studies will examine ways of optimizing sonophoretic and chemical enhancer parameters to achieve flux enhancement.     

Lack of pharmacokinetic interaction between ropinirole and theophylline in patients with Parkinson's disease

Objective: Ropinirole and theophylline have the potential to interact, because they use the same hepatic cytochrome P450 (CYP1A2) as their major metabolic pathway. The present study investigated the effect of steady-state oral theophylline on the pharmacokinetics of ropinirole at steady state and the effect of steady-state ropinirole on the pharmacokinetics of a single intravenous (i.v.) dose of theophylline, both in patients with idiopathic Parkinson's disease (PD). Methods: Pharmacokinetic parameters (AUC and C_max) for i.v. theophylline were compared before and after a 4-week period of oral treatment with ropinirole (2 mg t.i.d.) in 12 patients with PD. Patients were then maintained at this dose of ropinirole, and oral theophylline was co-administered at doses of up to 300 mg b.i.d. The parameters AUC, C_max and t_max for ropinirole were compared before, during and after oral theophylline co-treatment. Results: Co-administration of ropinirole did not significantly change the pharmacokinetics of i.v. theophylline (mean AUC with and without ropinirole: 68.6 μg · h⁻¹ · ml⁻¹ and 70.0 μ· h⁻¹ · ml⁻¹, respectively; mean C_max with and without ropinirole: 11.07 μ g · ml⁻¹ and 11.83 μg · ml⁻¹, respectively). Similarly, there were no significant changes in ropinirole pharmacokinetics when the drug was co-administered with oral theophylline (mean AUC for ropinirole with and without theophylline: 21.91 ng · h⁻¹ · ml⁻¹ and 22.09 ng · h⁻¹ · ml⁻¹, respectively; mean C_max for ropinirole with and without theophylline: 5.65 ng · ml⁻¹ and 5.54 ng · ml⁻¹, respectively; median t_max for ropinirole with and without theophylline: 2.0 h and 1.5 h, respectively). Conclusion: These results suggest a lack of significant pharmacokinetic interaction between the two drugs at current therapeutic doses. Received: 10 August 1998 / Accepted in revised form: 27 January 1999     

Transdermal Delivery of Cytochrome C—A 12.4 kDa Protein—Across Intact Skin by Constant–Current Iontophoresis

Purpose To demonstrate the transdermal iontophoretic delivery of a small (12.4 kDa) protein across intact skin. Materials and Methods The iontophoretic transport of Cytochrome c (Cyt c) across porcine ear skin in vitro was investigated and quantified by HPLC. The effect of protein concentration (0.35 and 0.7 mM), current density (0.15, 0.3 or 0.5 mA.cm⁻² applied for 8 h) and competing ions was evaluated. Co-iontophoresis of acetaminophen was employed to quantify the respective contributions of electromigration (EM) and electroosmosis (EO). Results The data confirmed the transdermal iontophoretic delivery of intact Cyt c. Electromigration was the principal transport mechanism, accounting for ∼90% of delivery; correlation between EM flux and electrophoretic mobility was consistent with earlier results using small molecules. Modest EO inhibition was observed at 0.5 mA.cm⁻². Cumulative permeation at 0.3 and 0.5 mA.cm⁻² was significantly greater than that at 0.15 mA.cm⁻²; fluxes using 0.35 and 0.7 mM Cyt c in the absence of competing ions (J _tot  = 182.8 ± 56.8 and 265.2 ± 149.1 μg.cm⁻².h⁻¹, respectively) were statistically equivalent. Formulation in PBS (pH 8.2) confirmed the impact of competing charge carriers; inclusion of ∼170 mM Na⁺ resulted in a 3.9-fold decrease in total flux. Conclusions Significant amounts (∼0.9 mg.cm⁻² over 8 h) of Cyt c were delivered non-invasively across intact skin by transdermal electrotransport.