权重配方模型的非线性混合效应分析:一个药物相互作用研究实例

目的:基于权重配方模型,采用非线性混合效应分析(NONMEM),对尿囊素、甲硝唑及地塞米松联合抗炎作用的组方合理性进行定量评价,结果与原算法比较。方法:实验数据为昆明种小鼠组织纤溶酶原激活物(t-PA)样品于405nm处的吸光度值,以权重配方模型为基本模型,组方间相互作用为固定效应,并考虑随机效应,通过NONMEM法建立最终模型,定量评价尿囊素、甲硝唑和地塞米松的联合抗炎作用及其交互作用。结果:基于整体效应的权重配方模型建立成功(P<0.001),X1X2(X1尿囊素,X2地塞米松)作为固定效应加入模型,最终模型中甲硝唑对整体药效作用不明显,尿囊素与地塞米松存在较强协同作用,都是主要起效组分,最优剂量配比尿囊素∶甲硝唑∶地塞米松=400∶131∶8.0(mg/kg,i.p.)。结论:采用NONMEM法,可全面考虑各组分间交互作用及个体间和个体内误差等随机效应,使权重配方模型更加严谨,与原算法比较,提供的信息量更大。     

麻黄汤不同配伍对大鼠发汗作用的定量评价

目的:基于麻黄汤不同配伍对大鼠发汗影响的实验数据,采用模型化与模拟化方法进行再分析,提取更多信息,阐明其配伍规律,为优化组方提供参考。方法:麻黄汤4个组分为L14(24+)正交设计,1水平为"使用",0水平为"不使用",药效指标为大鼠腋窝皮肤汗腺空泡发生率为作用指数。采用正交模拟法与非线性混合效应模型(NONMEM),分析各组分在复方背景下的重要程度和相互作用。模拟偏倚由4种视图及单组分实验结果综合评价。结果:麻黄汤各组分对大鼠发汗作用的药效影响按重要程度排序依次是桂枝(B)、麻黄(A)、杏仁(C)和甘草(D),药效最佳组合为麻黄+桂枝,最弱组合为杏仁+甘草。结论:麻黄汤发汗作用药效贡献最大的为麻黄、桂枝,且两者作用相当,发挥最佳发汗作用须两者联用。     

厄贝沙坦与氢氯噻嗪联用在大鼠体内剂量优化的定量研究

目的:应用权重配方法及非线性混合效应模型,对厄贝沙坦和氢氯噻嗪在肾性高血压大鼠体内联用的剂量优化进行定量评价。方法:根据权重配方设计,将肾性高血压大鼠分为厄贝沙坦和氢氯噻嗪不同剂量组合的6个用药组,以收缩压和舒张压的变化率作为药效指标。综合建立和应用权重配方模型及非线性混合效应模型分析降压效应,评价两药联用在大鼠体内的降压及交互作用,分析最佳剂量配比,并做确定性实验。对权重配方原法和权重配方群体法的计算结果进行比较。结果:成功建立权重配方模型及其群体模型,联用中组分重要程度为厄贝沙坦大于氢氯噻嗪,厄贝沙坦与氢氯噻嗪存在协同作用,在大鼠体内的最优剂量配比为厄贝沙坦∶氢氯噻嗪=10∶1。权重配方原法和群体法在评价组分重要程度、理论优化组方及剂量优化比例等方面的结论相同,但群体法由于采用个体效应值直接计算,对权重指数等参数的计算更为精确,并提供个体间及个体内变异等信息。结论:综合应用权重配方法及非线性混合效应模型,可定量评价厄贝沙坦和氢氯噻嗪联用在大鼠体内的药物相互作用规律,并提供最佳剂量配比的信息,为临床合理药物联用提供依据。     

紫苏配伍组方对高脂血症模型大鼠的调脂作用

目的研究紫苏配伍组方对高脂血症模型大鼠的调脂作用。方法采用高脂饲料喂养建立高脂血症大鼠模型，根据总胆固醇（TC）水平将大鼠随机分为7组：正常对照组、模型对照组、降脂灵片组、洛伐他汀组和紫苏配伍组方低、中、高剂量组。连续灌胃给药30 d，分别于给药第15天和末次给药后检测TC、三酰甘油（TG）、低密度脂蛋白胆固醇（LDL C）、高密度脂蛋白胆固醇（HDL C）含量。结果与模型组比较，紫苏配伍组方低、中、高剂量组和洛伐他汀组给药15 d后大鼠血清TC含量均显著降低；紫苏配伍组方低、中、高剂量组大鼠血清LDL C含量均显著降低。末次给药后紫苏配伍组方低、中、高剂量组，降脂灵组和洛伐他汀组与模型组比较大鼠血清TC含量均显著降低；紫苏配伍组方中、高剂量组与降脂灵组、洛伐他汀组大鼠血清LDL C含量均显著降低；紫苏配伍组方各剂量组、洛伐他汀组和降脂灵片组大鼠血清TG变化不明显；紫苏配伍组方中剂量组大鼠血清HDL C/ LDL C比值显著提高。结论紫苏配伍组方具有显著调脂作用。     

泽泻汤加味方治疗高血压最佳组方配伍研究

目的探讨泽泻汤加味方(泽泻、白术、泽兰、石菖蒲等四味药组成,在泽泻汤原方的基础上加用活血祛痰的泽兰、石菖蒲)治疗高血压最佳组方配伍。方法采用8%NaCl高盐饲料自然喂养法复制高血压大鼠模型,设计3因素3水平正交设计试验,根据降压作用,确定泽泻汤加味方最佳组方配伍。结果泽泻汤加味方降压效果最佳组方为:泽泻21 g,炒白术9 g,泽兰和石菖蒲各15 g,与目前临床常用药物比例及剂量基本吻合。结论泽泻汤加味方具有一定的降压作用,呈一定剂量依赖关系。初期的降压作用与其利尿作用有关,长期的降压作用是通过利水、活血、祛痰的综合作用实现的。     

降血糖多组分动态加减临床设计与组方优选方法的研究

目的 建立多组分动态配伍、随症加减设计方法和定量分析方法并进行35味降血糖中药组方优选.方法 设计采用"药味设限,辩证选药,随症加减.剂量可调",以及"随机、双盲、多组分动态配伍、安慰剂对照、多中心试验".将120例患者分为中药配伍组(102例)和安慰剂组(18例).筛选药味采用多元线性回归模型,建模和分析采用正交模拟和非线性混合效应模型法.分析指标为治疗4周的餐后2 h血糖下降值(2 h PG).结果 在35味中药中,天花粉(A)、知母(B)、葛根(C)、山药(D)、玄参(E)共5个组分的组方频率较高.D为主要药效组分(P<0.05);其次为C和B;E和A作用较小.ABCE、CD、AC与ACE有轻度协同作用;ABCDE组合有较强的拮抗作用;其他组合(ABCD、BCDE与BDE)有轻度拮抗作用.BCDE合用时,可达到2hPG最大效应(E=4.02mmol·L-1).结论 本研究方法对多组方筛选具有可行性,可获得大量组方定量设计信息.     

NONMEM法建立大鼠外周和中枢左旋多巴群体药动学模型

目的:建立大鼠左旋多巴(levodopa, LD)群体药动学模型,考察LD药动学参数的影响因素。方法:14只大鼠随机分为高、低两个剂量组,单次灌胃给予多巴丝肼片。采用脑微透析技术收集大鼠纹状体细胞外液透析液,同时采集外周血;高效液相色谱-电化学法测定透析液及血浆LD浓度,并利用非线性混合效应模型(Nonlinear mixed effect model, NONMEM)进行群体药动学数据分析。结果:建立了包含大鼠个体间变异、个体自身变异及体质量、给药剂量等固定效应参数的统计学模型,原始数据估算的参数值均位于Bootstrap估算参数值的2.5%~97.5%范围内,视觉预测评估法显示建模大鼠外周血和中枢纹状体LD浓度基本位于90%百分位数范围之内,所建立的最终模型稳定、有效、且有较强的预测能力。体质量可影响LD药动参数K₃₂。结论:建立的群体药动学模型能较好地描述LD在大鼠中枢及外周血的药动学特点。大鼠给药剂量对LD药动参数无影响,体质量可影响LD药动参数。     

冠心Ⅱ号方中芍药苷的群体药代动力学

本研究旨在分析冠心II号方中组分的变化对芍药苷药动学性质的影响.将大鼠随机分组后分别静脉注射芍药苷提取物(PPE)、灌胃给予PPE及三种不同组成的水煎液,HPLC法测定给药后不同时间血浆中芍药苷浓度,并用非线性混合效应模型(NONMEM)法对全部数据进行药动学模型拟合.吸收相中带有一级降解速率的二室口服吸收模型可以用于描述芍药苷的体内药动学特征,药动学参数CL1、V1、CL2、V2、Ka0及Kal的群体拟合值分别为0.509L/h,0.104 L,0.113L/h,0.123L,0.135 h-1及0.0135 h-1,模型对个体间差异进行了估计,并以给药剂型(DF)作为固定效应对参数Ka1、Ka0和V1进行了校正.群体药动学方法可以用于分析冠心II号中组方变化对芍药苷体内吸收和分布产生的影响.     

复方苦豆子颗粒对高脂血症大鼠血脂代谢的影响

目的:观察复方苦豆子颗粒对高脂血症大鼠血脂代谢的影响。方法:除空白对照组外,用喂饲高脂饲料法复制大鼠高脂模型,实验分空白对照组、高脂模型组、复方苦豆子颗粒组(低、中、高剂量组,分别喂饲生药7g.kg-1.d-1、15g.kg-1.d-1、22g.kg-1.d-1)、血脂康组(0.8g.kg-1.d-1),给药后每4wk抽1次血,连续3次,分别测定血浆总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、极低密度脂蛋白胆固醇(VLDL-C)、高密度脂蛋白胆固醇(HDL-C)、丙二醛(MDA)含量变化。结果:高脂模型组血浆TC、TG、LDL-C、VLDL-C、HDL-C和MDA含量显著上升,同时动脉粥样硬化指数(AI)增加;给予复方苦豆子颗粒4wk后,各组血浆TC、TG、LDL-C、VLDL-C、MDA及AI水平均降低,且呈剂量依赖性。结论:复方苦豆子颗粒对高脂血症大鼠具有调血脂作用。     

单因素配伍剂量对经方芍药甘草汤药效组分的影响

目的研究中药经方芍药甘草汤中炙甘草或醋白芍单因素配伍剂量变化对其药效组分的影响,为临床合理用药和建立中药药效组分质量评价标准提供科学依据。方法以单因素配伍剂量的醋白芍和炙甘草为载体,以经方芍药甘草汤作为对照,按照汤剂制备供试品溶液,采用HPLC-DAD法,三波长同时测定药效组分氧化芍药苷-芍药内酯苷-芍药苷-苯甲酰芍药苷-甘草酸(λ=230 nm)、甘草苷-甘草素(λ=276 nm)、异甘草苷-异甘草素(λ=360 nm)的含量。结果醋白芍剂量12 g不变时,其药效组分氧化芍药苷-芍药内酯苷-芍药苷-苯甲酰芍药苷的含量随炙甘草的剂量变化如下(mg/m L,n=3):炙甘草12 g,醋白芍组分含量为1.90-0.89-3.45-0.53;炙甘草为1、6、9、15、18 g时,醋白芍组分含量均降低。炙甘草剂量12 g不变时,其药效组分甘草酸-甘草苷-甘草素-异甘草苷-异甘草素的含量随醋白芍的剂量变化如下(mg/m L,n=3):醋白芍12 g,炙甘草的组分含量为9.06-3.19-0.76-0.77-0.15;醋白芍为1、6、9、15、18 g时,炙甘草组分含量均降低。结论 1炙甘草或醋白芍配伍剂量变化时,其药效组分的溶出率与经方比较有显著差异,表明改变中药的配伍剂量其功效会产生变化;2醋白芍-炙甘草剂量比越接近1∶1,其相应的药效组分溶出率越高;3醋白芍的4种药效组分总含量随炙甘草配伍剂量变化规律:炙甘草12 g>9 g>15 g>6 g>18 g>3 g>1 g,药效组分总量为6.77~4.15 mg/m L;4炙甘草的5种药效组分总含量随醋白芍配伍剂量变化规律:醋白芍12 g>9 g>15 g>6 g>18 g>3 g>1 g,药效组分总量为13.93~10.34 mg/m L;5炙甘草剂量对芍药甘草汤药效组分总量的影响大于醋白芍。     

中药配方颗粒的研究现状及问题

目的评述近几年来中药配方颗粒的研究现状及存在问题。方法查阅、综述、分析近几年来中药配方颗粒包括制备工艺及质量标准规范化等方面的研究文献。结果与结论中药配方颗粒具有安全卫生、计量准确、携带方便等优点,但存在一些亟待解决的问题。     

中药配方颗粒监管存在的问题与对策

目的：为中药配方颗粒产业健康发展和监管工作提供参考。方法：回顾国内外中药配方颗粒产业和监管情况,分析我国中药配方颗粒产业和监管存在的问题,提出相关对策。结果与结论：随着国家对传统中医药产业的重视,中医药利好政策不断发布,中药配方颗粒行业迎来快速发展期,且在生产、流通和使用方面逐步规范。然而市场份额的快速增长,对中药配方颗粒研发、生产、流通、使用等各环节的监管带来挑战。中药配方颗粒生产企业和使用单位应加强质量管理,药品监管部门应对中药配方颗粒的生产、流通、使用等方面加强监管,以保证中药配方颗粒质量安全有效,满足人民群众多样化的健康需求。     

Implementation of dose superimposition to introduce multiple doses for a mathematical absorption model (transit compartment model)

A mathematical absorption model (e.g. transit compartment model) is useful to describe complex absorption process. However, in such a model, an assumption has to be made to introduce multiple doses that a prior dose has been absorbed nearly completely when the next dose is administered. This is because the drug input cannot be determined from drug depot compartment through integration of the differential equation system and has to be analytically calculated. We propose a method of dose superimposition to introduce multiple doses; thereby eliminating the assumption. The code for implementing the dose superimposition in WinNonlin and NONMEM was provided. For implementation in NONMEM, we discussed a special case (SC) and a general case (GC). In a SC, dose superimposition was implemented solely using NM-TRAN abbreviated code and the maximum number of the doses that can be administered for any subject must be pre-defined. In a GC, a user-supplied function (FUNCA) in FORTRAN code was defined to perform dose superimposition to remove the restriction that the maximum number of doses must be pre-defined.     

制草乌、姜半夏中药配方颗粒与饮片煎剂的急性毒性比较研究

目的 比较制草乌、姜半夏配方颗粒与饮片煎剂的急性毒性差异。方法 参照国家药品监督管理局2014年发布的《药物单次给药毒性研究技术指导原则》,对制草乌、姜半夏配方颗粒与其饮片煎剂进行小鼠急性毒性实验,根据毒性实验结果的不同,分别以最小致死量（minimum lethal dose,MLD）或最大给药量（maximum administration dosage,MAD）来反映制草乌、姜半夏配方颗粒与其各自饮片煎剂的毒性差异。结果 制草乌饮片煎剂的MLD值在生药25.6~32 g·kg^-1之间,而制草乌配方颗粒的MLD值在生药40~50 g·kg^-1之间;姜半夏饮片煎剂与姜半夏配方颗粒小鼠灌胃的MAD均为生药238.872 g·kg^-1,以姜半夏在中国药典2015年版中的上限用量9 g·d^-1计算,相当于人用剂量的1 592.48倍。结论 制草乌颗粒的毒性明显低于制草乌饮片煎剂;姜半夏配方颗粒与饮片煎剂均未见毒性表现。     

地附补肾颗粒对肾虚致骨质疏松模型大鼠的影响及机制的实验研究

目的观察地附补肾颗粒对肾虚致骨质疏松模型大鼠的实验影响。方法将72只SD雌性大鼠随机分为6组:假手术组、模型组、阳性对照组(0.27g.kg-1)、地附补肾颗粒高(11.72 g.kg-1)、中(5.86 g.kg-1)、低(2.93 g.kg-1)组,每组12只,除假手术组,其余各组去势法切除双侧卵巢复制骨质疏松模型。造模后用药组给药8周,之后观察各组结果并作比较分析。结果地附补肾颗粒中剂量能显著提升骨质疏松模型大鼠的子宫指数、BMD、Ca2+、E2水平,通过降低TRAP、ALP活性降低骨高转换率,降低IL-6的表达。结论地附补肾颗粒通过补肾滋阴,可改善肾虚致骨质疏松模型大鼠的症状。     

Sample Size/Power Calculations for Population Pharmacodynamic Experiments Involving Repeated-Count Measurements

Repeated discrete outcome variables such as count measurements often arise in pharmacodynamic experiments. Count measurements can only take nonnegative integer values; this and correlation between repeated measurements from an individual make the design and analysis of repeated-count data special. Sample size/power calculation is an important part of clinical trial design to ensure adequate power for detecting significant effect, and it is often based on the procedure for analysis. This paper describes an approach for calculating sample size/power for population pharmacokinetic/pharmacodynamic experiments involving repeated-count measurements modeled as a Poisson process based on mixed-effects modeling technique. The noncentral version of the Wald χ² test is used for testing parameter/treatment significance. The approach was applied to two examples and the results were compared to results obtained from simulations in NONMEM. The first example involves calculating the power of a design to detect parameter significance between two groups: placebo and treatment group. The second example involves characterization of the dose-efficacy relationship of oxybutynin using a mixed-effects modeling approach. Weekly urge urinary incontinence episodes (a discrete count variable) is the primary efficacy variable and is modeled as a Poisson variable. A prospective study based on two different formulations of oxybutynin was designed using published population pharmacokinetic/pharmacodynamic model. The results of simulation studies showed good agreement between the proposed method and NONMEM simulations.     

Pharmacokinetics of felbamate, a novel antiepileptic drug: application of mixed-effect modeling to clinical trials

Felbamate is a novel antiepileptic drug currently undergoing clinical trials in the United States. Serum felbamate concentration data from a phase II safety and efficacy trial were analyzed using NONMEM. A one-compartment, open model with first-order absorption and elimination was used. Body weight, sex, concurrent folic acid therapy, and phenytoin dose and dose:concentration ratio did not affect the estimates for felbamate clearance (Cl). Carbamazepine dose and dose:concentration ratio (CDCR) led to significant improvements in the objective function. The final models for felbamate clearance and volume of distribution (Vd) were as follows: Cl(L/hr) = 2.43 + 0.429*CDCR/240, Vd (L) = 51. The coefficient of variation of clearance was only about 12%, which may be indicative of the highly selective patient population. The clearance estimates are similar to those obtained in healthy volunteers and in patients receiving lower dosages of felbamate. The volume of distribution estimate, however, is slightly smaller than that reported previously. Valuable pharmacokinetic information can be obtained from the routine monitoring of serum concentrations during safety and efficacy trials.     

Comparison of nonlinear mixed-effect and non-parametric expectation maximisation modelling for Bayesian estimation of carboplatin clearance in children

OBJECTIVE: The pharmacodynamic-pharmacokinetic relationships for carboplatin involve the area under the curve of ultrafiltrable plasma concentrations versus time (AUC). The objective of the study was to compare two specific population pharmacokinetic methodologies, nonlinear mixed-effect model (NONMEM) and non-parametric expectation maximisation (NPEM), when they are applied to sparse carboplatin pharmacokinetic data in order to obtain an individual value for carboplatin clearance by Bayesian estimation. METHODS: The data from 117 patients (from 1 month to 18 years old) were available. For 20 patients randomly selected, the carboplatin clearance obtained by Bayesian estimation using two plasma ultrafiltrable concentrations was compared with that obtained by individual analysis using all concentrations. RESULTS: Both methodologies were unbiased with mean relative percentage errors (95%CI) of -1.9% ( 7.8; +4.1%) and +6.4% (-2.1; +14.9%) for NONMEM and NPEM, respectively. A comparison of precision between the two methods showed that they were not significantly different (12.5% for NONMEM, and 18.9% for NPEM), but the percentage error ranged between -21% and + 19% for NONMEM, and -35% and + 42% for NPEM. A NONMEM analysis was also performed with all the data available (117 children) in order to update an equation describing the relationship between carboplatin clearance and the patients' covariates. The best relationship corresponded to the equation: clearance (ml/min) = [4.47 x body weight x (1 -0.22 x Np)/(l + 0.0156 x Scr)] +6.4, with body weight in kilograms and where Scr is serum creatinine in micromoles per litre and Np= 1 or 0 for unilateral nephrectomy or not, respectively. CONCLUSION: These methodologies may be useful for dose individualisation and drug monitoring of carboplatin in paediatric patients. Since the mode of administration of carboplatin in paediatric practice in some protocols is daily 1-h i.v. infusion repeated up to five times, dose individualisation may be performed from the clearance observed after the first administration, given an overall target AUC.     

Characterisation by X-ray microanalysis of metal granules in the mucus trails of Littorina littorea (Gastropoda) along a putative pollution gradient

Metal-containing granules in the mucus trails of the marine gastropod Littorina littorea from nine sites in north-east England were analysed for elemental composition by X-ray microanalysis and characterised relative to a putative gradient of pollution. Overall granule density varied significantly between sites, means of 6.5-17.0 per field of view (2688 microm2). Most granules found (64%) were poly-metal of a wide variety of compositions, but could be classified as Si+X, Mg+X, S+X, Na+X, P+Ca, P+Al, where X indicates any other combination of elements. Si+Al+X accounted for 61% of the poly-metal granules found and was considered to be contamination from the beach substratum. In single-metal granule form only Ca, Si, Fe, Ti, Al and Na were found. The most common single-metal granule at each site was of Ca, except at two sites, where the most common single-metal granule was of Si. The densities of these granule types varied between sites but differences were found to be significant only in the case of Si granules. Across all sites, single-metal granules of Si (mean = 2.49 microm +/- 1.44 SD, n = 141) and Ca (2.22 microm +/- 1.08 SD, n = 147) were significantly larger than granules of Fe (1.74 microm +/- 0.95 SD, n = 63) and Ti (1.24 microm +/- 0.52 SD, n = 18). The range of sizes was large: Ca (0.5-6 microm), Si (0.5-10 microm), Fe (0.3-4.1 microm), Ti (0.5-2.5 microm). Between the sites there were significant differences in the size of Fe and Si granules but not Ca or Ti granules. Despite these variations in granule type and size, there was no evidence of a relationship with pollution and consequently a detoxifying function of the mucus trail in metal polluted environments is not apparent.