帕拉米韦原料药的稳定性研究

目的考察帕拉米韦原料药在不同条件下的稳定性。方法采用高效液相色谱法。Welch ODS C18色谱柱(250mm×4.6 mm,5μm);流动相水(含0.1%冰醋酸)–乙腈(90∶10);检测波长210 nm;体积流量1.0 m L/min;柱温:25℃;进样量10μL。考察了帕拉米韦原料药在不同温度、光照和不同p H值下的稳定性。结果帕拉米韦原料药在100℃条件下48 h内是稳定的;在光照10 d的情况下,帕拉米韦的稳定性良好;帕拉米韦在碱性和中性环境下稳定性良好,在酸性条件下不稳定,随着p H值的降低,稳定性越差,在p H 1.0时,降解半衰期(t1/2)是43.6 h。结论帕拉米韦在酸性环境中极不稳定,在碱性和中性条件下稳定性良好。     

神经氨酸酶抑制剂帕拉米韦的合成及其抗禽流感病毒药效

目的 改进神经氨酸酶抑制剂帕拉米韦合成方法,提高其反应收率,确定其对人工感染禽流感病毒小鼠的防治效果、适宜剂量及给药方式.方法 以文斯内酰胺和2-乙基丁醛为主要原料,经催化开环、氨基保护、环化加成等步骤合成了帕拉米韦,通过1H NMR,13C NMR及MS等方法确定了中间体及目标化合物的结构.考察不同剂量和给药方式的帕拉米韦预防及治疗人工感染H9N2亚型禽流感病毒小鼠的药效.结果 合成帕拉米韦的总收率为52.7%,较文献提高了 28%.帕拉米韦对感染小鼠的保护效果具有剂量和治疗时间依赖性.40 mg/kg剂量的帕拉米韦一次性肌注,对感染小鼠的保护率为100%.感染病毒后2d内给药疗效较好.结论 帕拉米韦对感染禽流感病毒小鼠具有显著的防治效果,肌注效果较好.     

UPLC-MS/MS法测定帕拉米韦在大鼠体内的药物动力学

目的建立测定帕拉米韦在大鼠血浆中药物浓度的UPLC-MS/MS的方法,并且将这种方法用于帕拉米韦口服和静脉注射后大鼠体内的药动学。方法色谱柱为C18柱(50 mm×2.1 mm,1.7μm),使用梯度洗脱来分离被检测的物质,通过沉淀蛋白方法处理被测的血浆样品,采用多反应监测(multiple reaction monitoring,MRM)的方法对被测的样品进行扫描和检测。结果在线性范围内,帕拉米韦的线性关系良好,准确度为-8.0%~+8.0%之间,日内RSD<7.1%且日间RSD<7.1%,平均提取回收率>85%,基质效应为90%~110%。结论该方法简单易操作,适合于帕拉米韦在大鼠体内的药动学研究。     

非水滴定法测定帕拉米韦原料药中帕拉米韦

目的 建立帕拉米韦三水合物原料药中帕拉米韦的测定方法.方法 以0.1 mol/L高氯酸溶液为滴定液,以冰醋酸为溶剂,采用非水滴定法进行测定.结果 帕拉米韦样品溶液6h内稳定;重复性测定结果表明RSD值为0.07％(n=6).结论 该方法简单、准确,具有良好的重复性和稳定性,可作为帕拉米韦原料药的测定方法,为帕拉米韦的质量控制提供科学依据.     

盐酸美金刚胺前药MeN-1和MeN -2在人工胃肠液中的稳定性研究

考察盐酸美金刚胺前药MeN -1和MeN -2在人工胃肠液中的稳定性.方法采用HPLC法测定盐酸美金刚胺前药MeN -1和MeN -2在人工胃液和人工肠液中的浓度,并比较两者的稳定性.结果MeN -1在人工胃液中孵育3h后,其相对含量为90％,但在人工肠液中降至约70％;而MeN -2在人工胃肠液中孵育1h后,其相对含...     

高效液相色谱法测定不同时间人血浆中帕拉米韦的浓度及临床观察

目的 测定帕拉米韦给药后不同时间人血浆中的药物浓度,观察病人用药后安全性及疗效,为临床使用帕拉米韦提供依据.方法 高效液相色谱(HPLC)法测定帕拉米韦的血药浓度,以5 mmol/L磷酸二氢钾溶液(0.1％三乙胺)-乙腈为流动相,磷酸调pH 5.0;检测波长210 nm;流速1.0 mL/min;用药后对病人进行安全性随访.结果 血浆中无干扰测定的内源性物质,线性范围为1～50μg/mL,最低定量限(LLOQ)为1μg/mL,回收率102.5％～110.4％,日间精密度及稳定性均良好,5例病人不同时间血浆中的帕拉米韦均可检出;5例病人的发热缓解时间分别为33、26、26、48、54 h,流感症状缓解时间分别为89、>120、28、48、54 h,发生1例不良反应.结论 HPLC检测方法可靠,适用于人血浆中帕拉米韦的测定.帕拉米韦能快速缓解流感症状,虽然出现的不良事件为轻度,但也要监测其不良反应,以保证用药安全性及有效性.     

在体单向肠灌流模型研究帕拉米韦拟肽类衍生物的大鼠小肠吸收特性

目的研究帕拉米韦及其拟肽类衍生物的大鼠小肠吸收机制,筛选出膜渗透性最大的衍生物。方法采用大鼠在体单向灌流法研究帕拉米韦拟肽类衍生物的小肠吸收,采用高效液相色谱法测定药物和酚红的浓度。建立lgD预测值和lgP之间的关系。结果帕拉米韦拟肽类衍生物的膜渗透系数都比帕拉米韦高,其中帕拉米韦L-异亮氨酸衍生物具有最高的膜渗透性;寡肽转运蛋白(PEPT1)典型底物甘氨酰肌氨酸能显著降低帕拉米韦拟肽类衍生物的小肠吸收,而L-缬氨酸不具有这种能力。结论帕拉米韦拟肽类衍生物是PEPT1的底物,它们在大鼠小肠内的吸收是PEPT1介导的主动转运过程。     

神香草水提取物在模拟胃肠道环境中的稳定性

目的:研究神香草水提取物在模拟胃肠道环境下的稳定性。方法:采用HPLC法分别测定不同时间神香草水提取物中迷迭香酸及迷迭香酸单体在不同p H、人工胃液、人工肠液、大鼠肠道内容物及大鼠肠粘膜中的含量。结果:神香草水提取物中迷迭香酸和迷迭香酸单体均随p H升高稳定性降低;在人工胃液中均稳定,在人工肠液中稳定性差;在大鼠小肠内容物、大鼠大肠内容物及大鼠肠粘膜中的稳定性依次为:大鼠肠粘膜>大鼠小肠内容物≈大鼠大肠内容物;在灭菌后的大鼠小肠内容物、大肠内容物及肠粘膜中的稳定性基本一致;两者在灭菌后大鼠肠内容物和肠粘膜中均比灭菌前更加稳定;在上述各条件下,神香草水提取物中的迷迭香酸与迷迭香酸单体相比较更加稳定。结论:该研究比较了单体化合物和其在维药提取物中的稳定性,结果明确,为进一步研究神香草提取物的吸收代谢情况及成药后的剂型设计,奠定良好基础。     

帕拉米韦治疗流行性感冒的疗效及安全性分析

目的:帕拉米韦是新型的抗病毒药物,本研究拟评价帕拉米韦治疗流行性感冒的临床安全性。方法:以北京大学第三医院感染疾病科发热门诊就诊的流行性感冒患者89例为研究对象,所有患者均给予帕拉米韦氯化钠注射液3 mg·mL~(-1)治疗,单次静脉滴注,评价其发热、呼吸道和全身症状的缓解情况和药物的安全性。结果:患者平均年龄(28.31±8.30)岁。诊断为甲型流感84例,乙型流感5例。治疗后7 d随访,发热均缓解,缓解时间(24.92±14.44) h。主要不良事件包括消化道症状5例(5.62%),神经系统症状3例(3.37%)。心电图由治疗前的窦性心律变为治疗后的窦性心动过缓9例(10.11%),窦性心律不齐6例(6.74%),2例治疗后QTc间期延长。治疗前正常,治疗后2例丙氨酸氨基转移酶异常,15例(16.85%)甘油三酯升高,6例(6.74%)网织红细胞异常。无严重不良事件。结论:帕拉米韦治疗流行性感冒的安全性相对较高。     

53种中药丸剂在水与人工胃液中溶散时限的比较

前已报导,我们主张中草药浸膏片和半浸膏片的崩解时限,宜在人工胃液中测定。并报导38种银翅解毒片,在不同人工胃液中,采用中国药典(1977年版)或日本药局方(第十改正)的人工胃液配方与水比较,也     

Metabolism and Pharmacokinetics of Novel Oral Prodrugs of 9-[(R)-2-(phosphonomethoxy)propyl]adenine (PMPA) in Dogs

Purpose. A series of prodrugs designed to enhance the oral bioavailability of the antiretroviral agent 9-[(R)-2-(phosphonomethoxy)propyl]adenine (PMPA; 1) have been synthesized, including a bis-(acyloxymethyl) ester 2 and a series of bis-(alkoxycarbonyloxymethyl) esters 3-9. The in vitro biological stability andin vivo pharmacokinetics of these prodrugs were evaluated to support selection of a prodrug candidate for clinical evaluation. Methods. The in vitrobiological stability of the prodrugs was examined in dog tissues (intestinal homogenate, plasma and liver homogenate). The apparent half-lives were determined based on the disappearance of prodrug using reverse-phase HPLC with UV detection. Oral bioavailability of PMPA from each prodrug was determined in fasted beagle dogs. Concentrations of PMPA in plasma were determined by HPLC following fluorescence derivatization. Data for prodrugs were compared to historical data for intravenous PMPA. Results. All prodrugs were rapidly hydrolyzed in dog plasma and tissues (t_1/2 < 60 min). In fasted beagle dogs, bis-[(pivaloyloxy)methyl] PMPA (bis-POM PMPA) 2 had the highest oral bioavailability as PMPA (37.8 ± 5.1%). The oral bioavailabilities of PMPA from bis-(alkoxycarbonyloxymethyl) esters ranged from 16.0% to 30.7% and PMPA was the major metabolite formed. Conclusions. There was a correlation between oral bioavailability and intestinal stability of bis-(alkoxycarbonyloxymethyl) ester prodrugs (r² = 0.96). Lipophilicity (log P) was not a good predictor of oral bioavailability. The most labile prodrugs in dog intestinal homogenates, bis-(n-butyloxycarbonyloxymethyl) PMPA 5 and bis-(neo-pentyloxycarbonyloxymethyl) PMPA 8 (t_1/2 < 5 min) had the lowest oral bioavailabilities. Based on good oral bioavailability (30.1%), chemical and intestinal stability bis-(isopropyloxycarbonyloxymethyl) PMPA (bis-POC PMPA) 4 was selected as a candidate for clinical evaluation.     

丹酚酸B脂化乳的制备及其稳定性研究

目的制备丹酚酸B脂化乳,并考察其在人工胃肠液中的稳定性。方法制备丹酚酸B脂化乳粒、脂化乳。采用紫外分光光度法测定并比较脂化乳粒、脂化乳中丹酚酸B在人工胃液和人工肠液中的变化。结果不同制剂中丹酚酸B在人工胃液中的量均有所降低,但脂化乳和脂化乳粒均较水溶液中丹酚酸B的量高,3 h后丹酚酸B水溶液中药物的量分别较脂化乳、脂化乳粒少19.3%、6.4%。不同制剂中丹酚酸B在人工肠液中的量均有所降低,但脂化乳、脂化乳粒均较水溶液中丹酚酸B的量高,6 h后丹酚酸B水溶液中药物的量分别较脂化乳、脂化乳粒少32.7%、5.3%。结论丹酚酸B脂化乳、脂化乳粒均能提高人工胃、肠液中所包载药物的稳定性;且脂化乳效果优于脂化乳粒。     

Evaluation of a Targeted Prodrug Strategy to Enhance Oral Absorption of Poorly Water-Soluble Compounds

Purpose. The purpose of this research was to examine a targeted prodrug strategy to increase the absorption of a poorly water-soluble lipophilic compound. Methods. Three water-soluble prodrugs of Cam-4451 were synthesized. The amino acid (Cam-4562, Cam-4580) or phosphate (Cam-5223) ester prodrugs introduced moieties ionized at physiological pH and targeted intestinal brush-border membrane enzymes for reconversion to the parent. Selectivity for reconversion of the three prodrugs was examined in rat intestinal perfusate and brush-border membrane suspensions. Bioavailability of Cam-4451 in rats was evaluated after administering orally as the parent or as prodrugs in a cosolvent vehicle or in methylcellulose. Results. Cam-5223 was highly selective for reconversion at the brush-border, but was rapidly reconverted in intestinal perfusate. Cam-4562 was not as selective but was more stable in the perfusate, whereas Cam-4580 was neither selective nor stable. Oral bioavailability of Cam-4451 was 14% after dosing as the parent in the cosolvent vehicle, 39% and 46%, respectively, as Cam-4562 and Cam-5223. Oral bioavailability was only 3.6% when the parent was dosed in methylcellulose, whereas the bioavailability was 7-fold higher when dosed as the phosphate prodrug. Conclusions. Water-soluble prodrugs that target brush-border membrane enzymes for reconversion can be useful in improving drug oral bioavailability.     

丹参酮IIA脂化乳的制备及其稳定性研究

目的制备丹参酮ⅡA脂化乳,并考察丹参酮ⅡA脂化乳在人工胃肠液中的稳定性,为脂化乳作为口服制剂的合理性和可行性研究提供依据。方法制备丹参酮ⅡA混悬液、脂化乳、脂化乳粒。以原型药物为对照,采用紫外分光光度法测定不同制剂中丹参酮ⅡA的质量浓度。比较丹参酮ⅡA混悬液、脂化乳、脂化乳粒在人工胃液和人工肠液中的变化。结果不同制剂中丹参酮ⅡA在人工胃液中的质量浓度均有所降低,但脂化乳、脂化乳粒均较混悬液中丹参酮ⅡA质量浓度高。在人工胃液中,3 h后混悬液中丹参酮ⅡA质量浓度比脂化乳粒少11.8%、比脂化乳少33.3%。脂化乳粒、脂化乳在人工肠液中丹参酮ⅡA质量浓度几乎没有变化,混悬液中丹参酮ⅡA质量浓度有所降低,但较胃液中降低幅度有所缓和。在人工肠液中,6 h后混悬液中丹参酮ⅡA质量浓度比脂化乳粒少20.3%、比脂化乳少25.8%。结论丹参酮ⅡA脂化乳、脂化乳粒均能提高人工胃、肠液中所包载丹参酮ⅡA的稳定性,且脂化乳效果优于脂化乳粒,提示稳定体系有助于进一步提高人工胃、肠液中制剂稳定性。     

Aryl Ester Prodrugs of Cyclic HPMPC. I: Physicochemical Characterization and In Vitro Biological Stability

Purpose. The chemical, enzymatic, and biological stabilities and physical properties of a series of salicylate and aryl ester prodrugs of the antiviral agent, cyclic HPMPC, were evaluated to support the selection of a lead compound for clinical development. Methods. Chemical stabilities of the prodrugs in buffered solutions at 37°C were determined. Stability was also studied in the presence of porcine liver carboxyesterases (PLCE) at pH 7.4 and 25°C. Tissue stabilities were examined in both human and dog intestinal homogenates, plasmas and liver homogenates. Prodrug and product concentrations were determined by reverse phase HPLC. Results. Chemical degradation of the prodrugs resulted in the formation of both cyclic HPMPC and the corresponding HPMPC monoester. Chemical stability was dependent on the orientation of the exo-cyclic ligand; the equatorial isomers were 5.4- to 9.4-fold more reactive than the axial isomers. In the presence of PLCE, the salicylate prodrugs cleaved exclusively to give cyclic HPMPC and not the HPMPC monoester. In plasma, but not intestinal or liver homogenates, the salicylate esters of cyclic HPMPC cleaved readily with a rate dependent on the chain length of the alkyl ester substituent. Conclusions. The carboxylate function on the salicylate prodrugs of cyclic HPMPC provides an additional handle to chemically modify the lipophilicity, solubility and the biological reactivity of the prodrug. In tissue and enzymatic studies, the major degradation product is cyclic HPMPC. The salicylate ester prodrugs are attractive drug candidates for further in vivo evaluation.     

熊果酸前药的设计合成及抗多发性硬化症活性评价

目的 设计、合成熊果酸前药,以改善熊果酸的水溶性,并对其抗多发性硬化症(multiple sclerosis,MS)活性进行评价。方法 根据前药策略,选取了琥珀酸、二肽氨基酸和艾莎康唑侧链片段,通过缩合、酯化反应等与熊果酸的3位羟基进行结合,采用紫外-可见分光光度法测定前药的水溶性,并建立小鼠实验性自身免疫性脑脊髓炎模型来进行抗MS活性评价。结果 共合成了3个前药,目标化合物的结构经¹H-NMR、¹³C-NMR和LCMS(ESI)进行确证;前药1和2水溶性较熊果酸提升110倍以上,前药3水溶性提升200倍以上;体内抗MS活性结果显示,所得前药化合物的抗MS活性均有一定提高,其中前药1的抗MS活性显著高于熊果酸组,其机制可能是通过抑制外周炎症细胞浸润中枢以及抗脱髓鞘从而发挥抗MS活性;前药1体内代谢结果显示,前药1以原型形式在体内的暴露量为熊果酸的6倍,表明前药1可能主要是以钠盐原型发挥抗MS活性。结论 前药1具有较大的抗MS潜力,值得深入研究。该研究为开发具有抗MS活性的熊果酸前药提供一定依据及有益指导。     

盐酸去氢骆驼蓬碱在人工胃液、肠液及蒸馏水中的稳定性考察

目的:考察盐酸去氢骆驼蓬碱在人工胃液、人工肠液及蒸馏水中的稳定性。方法:采用高效液相色谱法测定盐酸去氢骆驼蓬碱的含量,用经典恒温加速法考察温度对其在不同条件下稳定性的影响。结果:盐酸去氢骆驼蓬碱检测浓度的线性范围为1.8～30.0μg.mL-1,在人工胃液、人工肠液、蒸馏水中的降解符合一级动力学过程,预测的有效期分别为566、69、22d。结论:盐酸去氢骆驼蓬碱在人工胃液、人工肠液、蒸馏水中的稳定性均较好。     

Ionized Prodrugs of Dehydroepiandrosterone for Transdermal lontophoretic Delivery

Purpose. The aim of this work was to synthesize ionized dehydroepiandrosterone (DHEA) prodrugs with higher water solubility, useful for iontophoretic transdermal application. Methods. The synthesized derivatives were characterized and tested for sensitivity to chemical and enzymatic hydrolysis. Solid state and solution stability was also determined. Transdermal iontophoretic anodal transport in vitro was studied using excised rabbit skin. Results. Two DHEA ionized prodrugs were synthesized: PRO1, a primary amine derivative, and PRO2, a quaternary ammonium salt. The two derivatives possess higher water solubility and lower octanol/saline partition coefficients than DHEA. Prodrugs were sensitive to enzymatic hydrolysis; in particular the primary amine was hydrolyzed faster than the quaternary salt by esterase from porcine liver in vitro. Transdermal flux of the two prodrugs was slightly higher than the parent drug. In the case of passive diffusion, only DHEA was found in the receptor compartment, indicating the complete breakdown of the prodrug in the skin. Current application gave higher drug flux and a significant amount of prodrug was found in the receptor. Conclusions. The use of ionized prodrugs of DHEA can increase the flux attainable during transdermal anodal iontophoresis by up to 7 times, but they are useful for passive transport as well.     

Prodrug and Analog Approaches to Improving the Intestinal Absorption of a Cyclic Peptide,GPIIb/IIIa Receptor Antagonist

Purpose. The purpose of this study was to test whether structural modifications improve the intestinal absorption of DMP 728 (cyclo(D-Abu-NMeArg-Gly-Asp-Amb)), a GPIIb/IIIa receptor antagonist. Methods. In vitro permeabilities of prodrugs and analogs of DMP 728 across excised rat intestinal segments were determined. Results. n-Butyl and n-octyl esters of DMP 728 were relatively stable during in vitro permeation of rat intestine. Intestinal permeation rates of these compounds were no greater than that of DMP 728, even though the octyl ester was much more lipophilic. A pivaloyloxymethyl ester, which was hydrolyzed to DMP 728 during intestinal permeation, also did not improve permeability. In another approach, analogs with an additional methyl substituent on various amide nitrogens were evaluated. Cyclo(D-Val-NMeArg-Gly-Asp-NMeAmb), cyclo(D-Abu-diN-MeLys-Gly-Asp-Amb), and cyclo(NMeGly-NMeArg-Gly-Asp-Amb) each had about 2-fold greater permeability than DMP 728. Two other analogs with improved permeability were linear Ac-D-Abu-NMeArg-Gly-Asp-Amb and a DMP 728 derivative in which the Asp was rearranged. An analog in which the charged amino acids were replaced by neutral amino acids had permeability similar to DMP 728. Conclusions. Within this series of peptides, hydrogen bonding tendency and structural constraint influenced intestinal permeation, but not always in ways consistent with the literature, whereas charge and lipophilicity were not shown to influence intestinal permeability. The failure of these approaches to improve permeation more significantly could be due to the influence of secretory transport.