维生素B2片溶出度测定研究

目的 用《中国药典》方法测定249批次维生素B₂片的溶出度,同时,考察其中6个厂家样品在4种不同pH值溶出介质中的溶出曲线,并对溶出度紫外法与HPLC测定法进行比较,为全面评价药品质量提供依据。方法 采用转篮法,4种不同溶出介质各600 mL,转速为100 r/min,检测波长444 nm;HPLC测定溶出度参考《中国药典》2015年版维生素B₂原料的含量测定方法。结果 维生素B₂片总体溶出状况较好,不同厂家样品、同厂家不同批号样品均有相似的溶出行为;液相法与紫外法测定差异较大。结论 溶出度测定紫外法专属性不高,建议采用液相法测定;部分厂家产品质量不稳定,应改善生产工艺。     

不同厂家复方丹参片物质组溶出度研究

目的 建立测定复方丹参片三组物质组（多指标物质组、指纹物质组、有效部位物质组）溶出度检测方法,并考察不同厂家复方丹参片物质组溶出度的情况。方法 按照《中国药典》2010年版二部附录XC溶出度测定第三法,以200 mL水为溶出介质进行溶出实验,并采用高效液相及紫外分别检测三组物质组的体外溶出度,绘制累积溶出曲线,且对各曲线进行相似因子的比较。结果 测定结果显示在60 min内除物质组一中丹参酮Ⅱ_A的溶出仅为23.41%外,其他物质组均能溶出95%以上,且不同厂家复方丹参片物质组溶出曲线相似因子f₂值大多小于50。结论 复方丹参片三组物质组的溶出度总体呈良好的相关性,故可作为质量检测的标准之一。不同厂家复方丹参片物质组的溶出度存在显著性差异,这可能是由于各厂家生产工艺不尽相同所致,因此建议中成药的质量控制应增加主成分或适宜物质组的溶出度检测。     

厄贝沙坦片的制备工艺与溶出度一致性研究

目的 制备厄贝沙坦仿制片并对其进行工艺与溶出度一致性研究。方法 以原研药（卡压舒®）为参比制剂,通过单因素实验考察黏合剂种类、黏合剂用量、片剂硬度、不同含水量和包衣增重对溶出度的影响,确定处方组成。放大制备3批厄贝沙坦仿制片,在4种不同溶出介质中考察3批样品和原研药的溶出一致性,通过相似因子（f₂）法评价自制与参比制剂溶出曲线的相似性。结果 3% HPMC-E5作为黏合剂较5% PVP K30作为黏合剂时稳定,黏合剂用量、硬度和水分在考察的范围内基本不影响,包衣增重2%~3%,3批自制片与原研片在不同溶出介质中f₂均大于50。结论 厄贝沙坦片制备工艺稳定且自制制剂与参比制剂在不同溶出介质中的体外溶出行为一致。     

伊潘立酮片溶出度一致性评价研究

目的 考察自制伊潘立酮片（1 mg规格）与参比制剂的溶出度一致性。方法 用HPLC法测定伊潘立酮在不同pH溶出介质中的溶解度,绘制伊潘立酮“pH-溶解度”曲线,测定自研制剂与参比制剂在4种不同pH溶出介质（0.1 mol/L HCl溶液、pH 4.5醋酸盐缓冲液、pH 6.8磷酸盐缓冲液、水）中的溶出度,绘制溶出曲线,用相似因子法进行拟合。结果 在所选4种溶出介质下,自研制剂与参比制剂的溶出曲线相似因子f₂值均大于50。结论 自研制剂与参比制剂能够达到体外溶出一致。     

基于多指标成分测定昆仙胶囊的体外溶出度

目的 建立昆仙胶囊多指标成分的溶出度测定方法，以有效控制其内在质量。方法 采用Agilent Zorbax SB-C₁₈色谱柱(250 mm×4.6 mm，5 μm)，以乙腈-0.1%磷酸水溶液为流动相进行梯度洗脱，流速为0.8 mL·min^–1，柱温33℃，检测波长270 nm。采用篮法，以900 mL pH 6.8的磷酸盐缓冲液为溶出介质，转速100 r·min^–1，测定昆仙胶囊中朝藿定A、朝藿定B、朝藿定C及淫羊藿苷的溶出度，并通过相似因子(f₂)法对不同批次样品的溶出曲线进行相似性比较。结果 朝藿定A、朝藿定B、朝藿定C及淫羊藿苷在各自范围内线性关系良好(r=0.999 9)，平均回收率分别为100.9%(RSD=1.29%)，102.1%(RSD=1.18%)，100.8%(RSD=1.30%)及99.9%(RSD=0.92%)，不同批次昆仙胶囊中4种成分的溶出曲线相似度较高，相似因子f₂均>67。结论 该法简便、准确、可行，专属性良好，可为昆仙胶囊的质量评价提供实验依据。     

非诺贝特片仿制药与原研药溶出度一致性评价研究

目的 建立非诺贝特片溶出度曲线测定方法,评价国内10家仿制药产品与原研药品溶出曲线的相似性。方法 用含0.025 mol·L^-1 SDS的pH 1.0盐酸溶液、pH 4.0缓冲液、pH 6.8缓冲液和水溶液4种溶出介质,分别考察非诺贝特片仿制药与原研片的溶出状况,并通过计算相似因子（f₂）评价溶出曲线的相似性。结果 国内仅1家企业产品与原研片在4种溶出介质中的溶出曲线均相似,其余企业产品与原研片相比溶出行为均不一致。结论 该方法适用于非诺贝特片的溶出曲线测定,可为非诺贝特片质量一致性评价提供参考。     

氯氮平片的溶出曲线考察

摘 要 目的： 考察氯氮平片在4种不同pH溶出介质中的溶出行为与参比制剂之间的差异,比较不同厂家药品的内在品质,为药品质量控制提供参考。方法: 通过体外溶出度试验,测定18家企业生产的46批氯氮平片在4种不同pH的溶出介质中的溶出曲线,用相似因子（f₂）法与参比制剂进行比较。结果: 共绘制46条溶出曲线,与参比制剂完全相似的批次仅占4%（一个企业的2个批次）,其余样品与参比制剂的溶出行为不一致。结论:目前国内该品种生产工艺差异较大,溶出行为与参比制剂存在差异。生产企业应加强处方工艺的筛选、优化,提高改进生产工艺。     

富马酸喹硫平片在4种溶出介质中溶出曲线的比较研究

目的 比较自研富马酸喹硫平片与国外原研药在4种不同pH的溶出介质中的体外溶出行为,为评价自研富马酸喹硫平片的质量及为制剂生产工艺提供参考。方法 采用《中国药典》2015年版（四部）通则0931第二法（桨法）,转速为50 r/min,分别以水、pH 1.0盐酸溶液、pH 4.5醋酸盐缓冲液和pH 6.8磷酸盐缓冲液为溶出介质,溶出介质体积为900 mL;以紫外-分光光度法测定富马酸喹硫平含量,并计算累积溶出度,绘制溶出曲线;采用相似因子（f₂）法评价溶出曲线的相似度。结果 在4种不同pH的溶出介质中,自研和原研富马酸喹硫平片溶出行为基本一致,30 min时溶出度均达到85%以上,f₂均大于50。结论 自研富马酸喹硫平片在4种溶介质中均可以完全释放,与原研制剂体外溶出行为均相似,能确保二者药品质量的一致性。     

基于生物等效性分析呋塞米片体内外试验的相关性

目的 开展体内外相关性试验以探讨国内生产的呋塞米片的药物溶出度试验是否可以替代生物等效性试验。方法 选择呋塞米片受试与对照制剂,按照中国药典要求和光纤药物溶出度实时测定仪测试方法,监测呋塞米累积溶出百分率并计算f₂相似因子,测定2种制剂的体内血药浓度并计算药动学参数,测算其体内吸收分数、生物利用度和生物等效性,分析呋塞米片体内外试验的相关性。结果 经f₂相似因子方法评估,受试与对照制剂的呋塞米溶出曲线相似,2种制剂的主要药动学参数t_max、C_max、AUC_0-24和AUC_0-∞、生物利用度和生物等效性均差异明显,其体内百分吸收系数和体内外试验的相关性较差。结论 国内生产的呋塞米片的药物溶出度试验尚不能替代生物等效性试验。     

采用不同介质中的溶出曲线评价硫酸氢氯吡格雷片的内在质量

目的 比较硫酸氢氯吡格雷片仿制药与原研药在4种不同溶出介质中溶出曲线的相似性。方法 分别以pH 2.0盐酸缓冲液、pH 4.5磷酸盐缓冲液、pH 6.8磷酸盐缓冲液和水为溶出介质测定2种片剂的体外溶出曲线,并采用f₂相似因子法考察其相似性。结果 在4种不同溶出介质中,2种片剂溶出曲线的f₂值分别为56,80,78和75。结论 2种片剂的体外溶出曲线在4种不同溶出介质中均相似。     

Simplified methods for the evaluation of the parameters of the time course of plasma concentration in the one-compartment body model with first-order invasion and first-order drug elimination including methods for ascertaining when such rate constants are equal

The many limitations in determining the pharmacokinetic parameters of firstorder invasion of, and elimination from, the onecompartment body model by the method of residuals or by feathering Ct data can be minimized by applying the simplified methods outlined herein. Comparisons of the apparent volumes of distribution, V, calculated on the premises that the Bateman Function represents k_a>k_e or its converse, k_e>k_a,i.e., flip-flop, can permit a proper choice of the correct version. Estimation of k_e can be obtained by regression of (A₀/V)/C(oncentration) on AUC₁/ Cwhere A₀/Vis estimable from knowledge of C_max and t_max since .The ratio of the magnitude of the rate constant of invasion to that of elimination, m=k_a/k_e,is related to k_et_max by the expression k_et_max=ln m/ (m–1)for all possible values of m.A table for the determination of m from values of k_et_max is given. When bioavailability, =A₀/Dose,is known or complete, k_e and Vcan be determined from the respective ordinate and abscissa of the intersection of and Cl(clearance)/k_e,both plotted against arbitrary k_e values. The two functions may not intersect at low values of mdue to errored C-t values but the k_e value when the two curves are closest (k_min)may approximate k_e.The intersections of and k_eAUCT (AUC_trap)plotted against variable k_e values (Method A) provide estimates of k_e from their abscissa values and A/Vfrom their ordinate values when is unknown. Method B appears to give more reliable estimates of k_e at the k_min of the difference plotted against k_e.Since k_min of this plot is 1/t_max when m=1,the identity of the mas unity underlying the C-t data is indicated when either k_mint_max is approximately unity or k_min ispractically synonymous with 1/t_max.This was clearly shown when 12 constructed m=1,C-t cases with 10% random error were evaluated by Method B. Better estimates were effected by all procedures when the raw C-t data were smoothed.We regretfully announce that Dr. Edward Garrett passed away on October 25, 1993, after an extended illness.     

dl-15-甲基PGF2α及其甲酯的HPLC分析研究

dl-15-甲基PGF_2α及其甲酯为前列腺素PGF的衍生物。它们的临床剂量甚小,其合成生产工艺及结构特征表明可能有多种异构体存在,且异构体间的生物活性差异很大。建立具有高专属性、灵敏度以及对各种制剂适用的分析方法是改进生产工艺、深入各项研究和临床安全有效使用所面临的迫切课题。本文报道的反相HPLC直接测定法用ODS柱、UVλ197nm检测、甲醇—水—醋酸为流动相,合成杜鹃素为内标,可对dl-15-甲基PGF_2α及其甲酯的各种差向和顺反异构体进行分离和分别直接定量。本法分辨率高,最低检测量为0.03μg,操作简便,定量线性关系良好,分析误差小于3%(CV),节省试剂,并可发展成制备工艺。本法适用于15-甲基PGF_2α及其甲酯的合成原料和各种制剂的分析。     

整合素αvβ3拮抗剂的研究进展

肿瘤生长初期没有新血管生成（无血管期）,其生长到一定程度时依赖新生血管的维持.肿瘤血管生成是肿瘤生长和转移的形态学基础,它不仅向肿瘤提供营养,也向宿主输出大量的肿瘤细胞导致肿瘤的生长和转移.因此对以抑制肿瘤血管生成为目的的抗肿瘤药物的研究方兴未艾,有很多具有抑制肿瘤血管生成作用的化合物如大黄素与青蒿琥酯等被发现.整合素αvβ3介导血管内皮细胞和肿瘤细胞的黏附,参与血管生成和肿瘤转移,在肿瘤生长中起重要作用.当其功能受到抑制时,血管内皮细胞出现凋亡,肿瘤生长受到抑制,甚至肿瘤消退.整合素αvβ3受体拮抗剂作为抗新生血管肿瘤药物的同时,对骨质流失、血栓、风湿性关节炎的治疗也起了重要作用.     

Kinetic evidence for a common binding site for substrates and inhibitors of the neuronal noradrenaline carrier

Summary The neuronal noradrenaline uptake mechanism (uptake₁) has been further characterized. For a number of substrates of uptake, the half-saturating concentration (K _m) and the maximal initial transport rate (V _max) were determined. Furthermore, the dissociation constants (K _D) for binding of these substrates to the desipramine binding site of the neuronal noradrenaline carrier were measured. The uptake experiments were done on rat phaeochromocytoma cells (PC12 cells), the binding experiments on purified plasma membranes of PC12 cells. The substrates differed markedly in respect of V _max, K _m, and K _D. Neither K _m and V _max nor K _D and V _max were found to be correlated. However, the discrepancy between K _m and K _D expressed as the ratio, K_m/K_D, was negatively correlated with V _max (r = – 0.9315, n = 7, p < 0.01).For the interpretation of these results a model on the basis of the steady-state assumption has been proposed for uptake₁. From the mathematics of that model the following conclusions can be drawn. (1) The half-saturating substrate concentration (K _m) is not identical with the dissociation constant for the binding of a substrate to the substrate recognition site (K _D). (2) The discrepancy between K _m and K _D is expected to be negatively correlated with the maximal initial transport rate of the substrate (V _max).The experimental results are in good agreement with the proposed model for uptake,. Especially the negative correlation between K _m/K _D and V_max supports the hypothesis that desipramine inhibits uptake, via binding to the substrate recognition site of the neuronal noradrenaline carrier.This study was supported by the Deutsche Forschungsgemeinschaft (SFB 176) Send offprint requests to E. Schömig at the above address     

Correlations betweenin vitro dissolution rate and bioavailability of alaproclate tablets

In two different absorption studies, quantitative correlations between the in vitro dissolution rate and the bioavailability have been shown after single administration of various tablet compositions of alaproclate hydrochloride to healthy subjects. Both statistical moment analysis and the use of empirical single value parameters were tested. For conventional tablets a linear relationship was obtained between mean dissolution time in vitro and in vivo. A similar relationship was obtained between the mean dissolution time in vitro and the mean residence time for controlled release tablets of the matrix type. It was also possible to establish an in vitro-in vivo correlation for these latter tablets by using the single point estimate of maximum plasma concentration as in vivo parameter. When comparing the mean dissolution time in vitro to the total area under the plasma drug concentration-time curve attained after different types of tablets, it is obvious that the extent of bioavailability of alaproclate will not fall below 80% of the value found for an aqueous solution until the mean dissolution time in vitro exceeds approximately 3 hr. Statistical moment analysis seems to have a broader applicability than the use of empirical point estimates, and it seems to be useful both for conventionally dissolving tablets and controlled release tablets.     

Studies on the specificity of CNF, a phospholipase A2 inhibitor isolated from the blood plasma of the South American rattlesnake (Crotalus durissus terrificus). I. Interaction with PLA2 from Lachesis muta muta snake venom

A phospholipase A₂ inhibitor has been previously purified and cloned from the blood plasma of the South American rattlesnake, Crotalus durissus terrificus. This inhibitor, named CNF for Crotalus neutralizing factor, interacts with crotoxin, the main neurotoxin from C. d. terrificus venom, abolishing its phospholipase A₂ activity. Crotoxin is a heterodimer of an acidic subunit (CA) and a basic phospholipase A₂ (CB). CNF acts by forming a stable non-toxic complex with CB, replacing CA in the toxic CA–CB of crotoxin.In the present investigation, we have shown that CNF has a broader specificity. It is able to inhibit the PLA₂ activity of the whole venom from the bushmaster snake (Lachesis muta muta), a species evolutionary related to Crotalus. Inhibition experiments have been carried out with four PLA₂ active components isolated from L. m. muta venom, one basic and three acidic ones. CNF inhibition is not restricted to the basic PLA₂, but extended to the three acidic forms as well.     

Unique approach for calculation of first-order absorption rate constants from blood or urine data

Several methods are employed to estimate an apparent first-order rate constant for absorption in a one-compartment model. A method for calculation of the absorption rate constant (K _a )has been derived based on the area under the concentration-time curve for blood data or the area under the excretion rate-time curve for urine data between the observed time of maximum concentration or rate (t _max )and the maximum concentration (C _max )or maximum rate of excretion (X _umax ).The method obviates the need for large numbers of samples in the absorptive phase. The method also avoids extensive calculations and is less influenced by errors in data points prior to C_max or X_{u max},where the rate of change is rapid and error is likely. The methods have been tested on theoretical data with and without error generated using a range of values for K_a and elimination rate constants (K _E ).Errors in the estimate of K_a are proportional to error in the data. The method compares favorably with nonlinear regression analysis.     

胞二磷胆碱联合尿激酶治疗急性脑梗死的临床研究

目的探讨急性脑梗死应用胞二磷胆碱联合尿激酶治疗的临床效果。方法选取2016年1月—2018年6月襄阳市中心医院收治的102例急性脑梗死患者,运用随机数字表法随机分成对照组和治疗组,每组各51例。对照组静脉滴注注射用尿激酶,100万U注射用尿激酶溶于100 mL生理盐水,持续静脉滴注30 min,单次给药。治疗组在对照组治疗基础上静脉滴注胞二磷胆碱注射液,0.75 g加入150 mL生理盐水充分稀释,给药时间应大于40 min,1次/d。两组均治疗两周。观察两组的临床疗效,比较两组患者治疗前后血小板参数、国立卫生研究院卒中量表(NIHSS)评分、凝血–纤溶指标、脑血流动力学参数的变化情况。结果治疗后,对照组和治疗组的总有效率分别为76.5%、92.2%,两组比较差异具有统计学意义(P0.05)。治疗后,两组血小板计数(PLC)显著增加,但血小板最大聚集率(PAGT_(max))值和NIHSS评分均较治疗前显著减少,同组治疗前后比较差异有统计学意义(P0.05);治疗后,治疗组PLC值高于对照组,PAGT_(max)值和NIHSS评分低于治疗组,两组比较差异具有统计学意义(P0.05)。治疗后,两组纤维蛋白原(FIB)、D-二聚体(D-D)、外周阻力(R_v)水平均显著下降,两组平均血流速度(V_(mean))和平均血流量(Q_(mean))值较治疗前均显著增高,同组治疗前后比较差异有统计学意义(P0.05);治疗后,治疗组FIB、D-D、R_v水平显著低于对照组,V_(mean)和Q_(mean)显著高于对照组,两组比较差异具有统计学意义(P0.05)。结论胞二磷胆碱联合尿激酶治疗急性脑梗死具有较好的临床疗效,可有效抑制患者体内血小板活性,纠正凝血–纤溶系统紊乱,维持脑血流动力学稳定,减少神经功能缺损,具有一定的临床推广应用价值。     

The effect of papaverine on local tissue P O 2 and microflow in cat brain cortex

Summary The effect of intracarotid and intravenous administration of papaverine on local tissue P _{O 2} and microflow in the cat's brain surface was studied. Local tissue P _{O 2} was measured with a multiwire surface electrode polaroraphically, and microflow by local hydrogen clearance method.The intracarotid infusions were made for 1, 2 and 5 min with doses of 0.1, 0.2 and 0.5 mg/kg/min papaverine, and the intravenous ones for 5 min with doses of 0.2, 0.5 and 1 mg/kg/min.The continuous intracarotid infusions showed that papaverine in the doses used distinctly increased local tissues P _{O 2} and microcirculation of the brain surface. With the doses applied, systemic arterial pressure (SAP) changed little. It slightly decreased only during the 5 min infusions containing 0.5 mg/kg/min. The duration of the effect increased with increases in the duration of the infusion and of the dose. The maximum duration was observed with 5 min infusions and lasted for 10–15 min after drug administration was discontinued. During the i.v. infusions, tissue P _{O 2} and microflow rose less than with intracarotid ones. No redistribution of capillary flow was observed.     

Identification of cytochromes<Emphasis Type="Italic"> P</Emphasis><Subscript>450</Subscript> 2C9 and 3A4 as the major catalysts of phenprocoumon hydroxylation in vitro

Objective This in-vitro study aimed at an identification of cytochrome P₄₅₀ (CYP) enzymes catalysing the (S)- and (R)-hydroxylation of the widely used anticoagulant phenprocoumon (PPC) to its major, inactive metabolites.Methods Relevant catalysts were identified by kinetic, correlation and inhibition experiments using human liver microsomes and recombinant enzymes.Results Kinetics revealed (S)-7-hydroxylation as quantitatively most important. Biphasic Eadie-Hofstee plots indicated more than one catalyst for the 4-, 6- and 7-hydroxylation of both enantiomers with mean K_m1 and K_m2 of 144.5±34.9 and 10.0±6.49 µM, respectively. PPC hydroxylation rates were significantly correlated with CYP2C9 and CYP3A4 activity and expression analysing 11 different CYP-specific probes. Complete inhibition of PPC hydroxylation was achieved by combined addition of the CYP3A4-specific inhibitor triacetyloleandomycin (TAO) and a monoclonal, inhibitory antibody (mAb) directed against CYP2C8, 9, 18 and 19, except for the (R)-4-hydroxylation that was, however, inhibited by ~80% using TAO alone. (S)-PPC hydroxylation was reduced by ~2/3 and ~1/3 using mAb2C8–9-18–19 and TAO, respectively, but (R)-6- and 7-hydroxylation by ~50% each. Experiments with mAbs directed against single CYP2C enzymes clearly indicated CYP2C9 as a major catalyst of the 6- and 7-hydroxylation for both enantiomers. However, CYP2C8 was equally important regarding the (S)-4-hydroxylation. Recombinant CYP2C8 and CYP2C9 were high-affinity catalysts (K_m <5 µM), whereas CYP3A4 operated with low affinity (K_m >100 µM).Conclusion CYP2C9 and CYP3A4 are major catalysts of (S)- and (R)-PPC hydroxylation, while CYP2C8 partly catalysed the (S)-4-hydroxylation. Increased vigilance is warranted when PPC treatment is combined with substrates, inhibitors, or inducers of these enzymes.Part of this work was presented at the 6th Congress of the European Association for Clinical Pharmacology and Therapeutics, Istanbul, June 2003.