多通道光纤化学传感器连续在位监测固体制剂的体外溶出度

采用基于荧光猝灭原理的多通道光纤化学传感器连续在位监测固体制剂的体外溶出度。采用自制光纤荧光溶出度监测仪与ZRS－4型智能溶出仪联用，连续在位监测氧氟沙星片、甲硝唑片、呋喃妥因肠溶片的体外溶出度，溶出曲线经微机从五种常用数学模型中根据相关系数r值，优选最佳模型进行拟合。方法的回收率分别为97.4%－104.4%、97.4%-103.8%、96.6%-102.1%，日内、日间的RSD＜5％。经与中国药典2000版方法及美国药典23版方法对照，各时间药物累积溶出量和拟合后提取的参数均无显著性差异（P＞0.05）。     

测量复方药物溶出度的全自动药物溶出度测定仪

自行设计组装了一套可以同时测定复方药剂的全自动药物溶出度测定仪.该仪器由光学检测系统(由光源、流动型吸收池,小型光谱仪组成)、自动进样系统、控制与数据处理系统和机械搅拌系统4部分组成.光学系统的检测器是线阵电荷耦合器件(CCD),故可进行同时全光谱采集.数据处理部分采用了自行设计的基于径向基函数的人工神经网络进行浓度预测.用本装置对市售复方药剂鲁南贝特进行的溶出度测量表明,测量的精密度高,准确度较高,分析速度快,样品无需前处理.     

测量复方药物溶出度的全自动药物溶出度测定仪

自行设计组装了一套可以同时测定复方药剂的全自动药物溶出度测定仪。该仪器由光学检测系统（由光源、流动型吸收池，小型光谱仪组成）、自动进样系统、控制与数据处理系统和机械搅拌系统4部分组成。光学系统的检测器是线阵电荷耦合器件（CCD），故可进行同时全光谱采集。数据处理部分采用了自行设计的基于径向基函数的人工神经网络进行浓度预测。用本装置对市售复方药剂鲁南贝特进行的溶出度测量表明，测量的精密度高，准确度较高，分析速度快，样品无需前处理。     

复方磺胺甲噁唑分散片溶出度方法学研究

建立准确、快速的溶出度测定方法.紫外双波长分光光度法.线性范围磺胺甲噁唑浓度在2.770～16.62μg/mL范围内,r=0.9993;甲氧苄啶浓度在1.260～7.560 μg/mL范围内,r=0.9994;平均回收率分别为磺胺甲噁唑99.65±0.10%,甲氧苄啶100.8±0.55%.本方法能准确、快速地测定复方磺胺甲噁唑分散片的溶出度.     

吸光度比值分光光度法测定复方氯唑沙宗片中氯唑沙宗和对乙酰氨基酚

根据吸光度比-光谱曲线,选定215.7 nm及264.1 nm作为测定氯唑沙宗(CRXZ)和对乙酰氨基酚(ACAP)的波长对。制备标准曲线时,首先配制由CRZX和ACAP基准物配制的标准溶液和由两者配成的混合标准系列,并在上述两波长处分别测得各试液的吸光度,再用文中提供的公式计算吸光度比值R和吸光度之差ΔR,最后建立ΔR对CRZX或ACAP浓度之间的线性回归方程。分析试样时,取复方氯唑沙宗片适量溶于溶剂中并定量稀释。分取部分试液按制备标准曲线的方法测得试液的吸光度并计算其比值R和ΔR。根据相应回归方程计算相应组分的含量。精密度及回收率试验所得结果的RSD(n=7)值为1.28%(CRXZ)及0.84%(ACAP),两者的平均回收率均为100.0%。     

氯唑沙宗的电化学行为及测定

建立灵敏快速测定氯唑沙宗的新方法。在0.24 mol·L-1KH2PO4-Na2HPO4(pH6.81±0.1)支持电解质中,氯唑沙宗于0.80 V(vs.SCE)电位处产生一还原波。加入过二硫酸钾后,该还原波峰电流增加约10倍,峰电位基本不变,产生一极谱催化波。其二阶导数峰电流Ip″与氯唑沙宗的浓度在2.0×10-7~8.0×10-5mol·L-1范围内呈良好线性关系(r=0.9981,n=8),检出限为1.0×10-7mol·L-1。该方法可用于药剂中氯唑沙宗含量的测定。     

阿司匹林双嘧达莫片溶出度及含量测定方法研究

建立了阿司匹林双嘧达莫片溶出度和含量的测定方法。采用Amethyst C18-H色谱柱(4.6 mm×250 mm, 5μm),以磷酸盐缓冲液-甲醇-乙腈为流动相，梯度洗脱，流速1.0 mL/min,检测波长235 nm。溶出度实验采用篮法，以0.1 mol/L盐酸溶液和磷酸盐缓冲液(pH 6.8)为溶出介质。结果表明：溶出度实验中双嘧达莫、阿司匹林和水杨酸质量浓度分别在0.5508～49.57、1.668～150.1和0.2004～18.04μg/mL范围内线性关系良好(r²≥0.9998),回收率在97.7%～102.0%之间(RSD≤1.0%,n=6)。含量测定实验中阿司匹林和双嘧达莫质量浓度分别在29.71～267.4μg/mL和10.42～93.78μg/mL范围内线性关系良好(r²≥0.9999),回收率在98.1%～101.0%之间(RSD<1.0%,n=9)。本方法准确性好、精密度高、操作简单，适用于阿司匹林双嘧达莫片溶出度和含量测定。     

富科思研发药物溶出度分析仪国内首创

经新疆富科思生物技术发展有限公司科研人员的共同努力，成功研发了具有自主知识产权、光机电一体化的“光纤传感药物溶出度分析仪”。     

一种酞菁锌纳米粒的体外溶出度测定方法的建立与溶出曲线评价

体外溶出是纳米药物重要的质量控制指标,本文对酞菁锌纳米粒的体外溶出进行研究。首先,对比紫外可见和荧光分光光度计对酞菁锌纳米粒中酞菁锌测定的专属性,并建立其标准曲线及进行精密度、回收率实验。之后用透析法测试体外溶出,对比不同溶出介质及取样处理方法对酞菁锌纳米粒中酞菁锌溶出情况的影响并用软件模拟释放模型。结果显示以荧光分光光度计检测时,酞菁锌在0.4～1.9μg·mL^-1范围内线性关系良好,相关系数为0.9991。在0.5、1.0、1.5μg·mL^-1三个水平下,相对标准偏差(RSD)为1.16～2.32%,精密度良好,且在加样回收实验中回收率为99.40～106.23%。此外,以通常的磷酸缓冲液(PBS)加1%十二烷基硫酸钠(SDS)为溶出介质,将取样冻干后DMF稀释并用荧光分光度计检测。在84 h时,pH 5.0/50μM H₂O₂组累积溶出可达58.21%。该组体外释放曲线最符合Ritger-peppas方程模型,即药物扩散和骨架溶蚀的共同作用释放机制。     

阿奇霉素片及胶囊剂溶出度考察

采用硫酸显色法对两家药厂生产的阿奇霉素片及胶囊剂进行了溶出度考察。结果表明，阿奇霉素在10－100μg/mL范围内线性关系良好，平均 回收率为99．83％（n=6)。阿奇霉素片及胶囊剂在45min时的溶出量均不低于标示量的80％。而两厂产品体外溶出度结果均达到要求。     

Dissolution enhancement of quercetin through nanofabrication, complexation, and solid dispersion

The main aim of this study was to enhance the dissolution rate of a poorly water-soluble antioxidant drug, quercetin, by fabricating its nanoparticles, complexes and solid dispersions using evaporative precipitation of nanosuspension (EPN). We studied the influence of the type of antisolvent, drug concentration and solvent to antisolvent ratio on the quercetin particles formed during EPN. With water as antisolvent, the particles were big, irregular and flake type but with benzene or hexane as antisolvent, the particles were smaller and needle type. Smallest particles of 220 nm diameter were achieved with hexane as antisolvent, lowest drug concentration and highest solvent to antisolvent ratio. The relative dissolution values showed that the dissolution rate of the EPN prepared quercetin nanoparticles was much higher than that of the raw drug. Quercetin formed inclusion complexes with β-cyclodextrin, and solid dispersions with polyvinylpyrrolidone and pluronic F127, where quercetin was present in an amorphous form and/or was dispersed at a molecular level. The dissolution rate of quercetin in its complexes and solid dispersions improved significantly from the raw quercetin as indicated by the percent dissolution efficiency. It was interesting to note that at lower carrier concentration, the solid dispersions of quercetin with polyvinylpyrrolidone and pluronic F127 presented better dissolution than its complex with β-cyclodextrin but at higher carrier concentration, there was no significant difference in the dissolution behavior of the three formulations. Using Korsmeyer-Peppas model, diffusion was found to be the main release mechanism.     

Dissolution of cellulose in ethylene diamine/salt solvent systems

Investigation of the dissolution of cellulose in Ethylene Diamine (EDA)/Potassium thiocyanate (KSCN) solutions by infrared spectroscopy (FTIR) and thermal analysis (DSC) indicated that changes to the solvent during freeze thaw cycling of mixtures was consistent with increased interaction between cellulose and solvent. Thermal transitions in the system, however, occurred at temperatures outside the range used in thermal cycling to promote dissolution. Further exploration of the dissolution and mixing process indicated that mixing was the limiting step in solution formation. The dissolution of two types of cellulose with different molecular weights (Degree of Polymerization (DP)=210 and >1000) was studied using EDA/KSCN solution as the solvent. The solubility and the dissolution rate of cellulose depended on both the solvent composition and cellulose molecular weight. Cellulose could dissolve faster in the solvent with lower salt concentration but the highest cellulose concentration was obtained in the solvent with 30~35% KSCN. Rheological measurements showed that cellulose solutions exhibited viscous solution behavior at low KSCN concentration but primarily elastic behavior at high salt concentration.     

Rapid determination of fumonisins in corn-based products by liquid chromatography/tandem mass spectrometry

A simple, fast, and robust method was developed for the determination of fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3) in corn-based human food and animal feed (cornmeal). The method involves a single extraction step followed by centrifugation and filtration before analysis by ultra-performance liquid chromatographylelectrospray ionization (UPLC/ESI)-MS/MS. The LC/MS/MS method developed here represents the fastest and simplest procedure (<30 min) among both conventional HPLC methods and other LC/MS methods using SPE cleanup. The potential for high throughput analysis makes the method particularly beneficial for regulatory agencies and analytical laboratories with a high sample volume. A single-laboratory validation was conducted by testing three different spiking levels (200, 500, and 1000 ng/g for FB1 and FB2; 100, 250, and 500 ng/g for FB3) for accuracy and precision. Recoveries of FB1 ranged from 93 to 98% with RSD values of 3-8%. Recoveries of FB2 ranged from 104 to 108%, with RSD values of 2-6%. Recoveries of FB3 ranged from 94 to 108%, with RSD values of 2-5%.     

Cholesterol Monohydrate Dissolution in Bile Salt‐Lecithin Solutions

A modified dissolution rate equation was used to quantitatively investigate the contribution of simple bile salt (BS) micelles and mixed BS‐lecithin (L) micelles to a cholesterol monohydrate (ChM) dissolution. Using a least‐squares technique to assess the relationship between the ChM dissolution rate and BS concentration at a constant L concentration, good curve‐fittings were obtained when the BS monomer concentration was set to equal the critical micellar concentration (CMC). For taurochenodeoxycholate (TCDC), a dihydroxy BS, the resulting values of parameters show that the simple TCDC micelle rate constant (ks) increases, but the mixed TCDC‐L micelle rate constant (kM ) decreases with increasing L concentrations. As for taurocholate (TC), a tri‐hydroxy BS, a ChM dissolution study was conducted over the initial 2 hour period in different TC‐L solutions. A similar curve‐fitting analysis revealed that the simple TC micelle ks is independent of L concentration and is much higher than the kM of mixed TC‐L micelles. Moreover, the outcome of the analysis supports previously reported equilibrium dialysis study results concerning the BS to L ratio of mixed BS‐L micelles. According to the collision theory, the resulting ks and kM values are interpreted.     

Determination of Iodine in Cereal Grains and Standard Reference Materials by Neutron Activation Anaylsis

Abstract

Trace amounts of iodine in thirty-eight cereal grain samples cultivated at different locations in Austria were determined for the first time in this study by radiochemical neutron activation analysis. For the dissolution of cereal grain samples and standard reference materials, two different procedures, alkaline and acidic dissolution, were applied in the presence of an iodine carrier. Rapid and simple dissolution procedure with acidic solution was demonstrated in this study. The analytical values in the cereal grain as well as in the standard reference materials obtained by the different dissolution procedures were in good agreement within one standard deviation. The iodine in cereal grains and the standard reference materials ranged from 0.002 to 0.03 μg g^?-1 and 0.0015 to 0.30 μg g^?-1, respectively. The distribution of relative standard deviation (RSD) for iodine concentration below 0.01 μg g^?-1 were 21% and 24% of all data for the range 1–10% RSD and 11–20% RSD, respectively. The RSD for 0.1 μg g^?1 of iodine concentrations were around 10%     

Simultaneous determination of caffeine, ergotamine, and metamizol in solid pharmaceutical formulation by HPTLC-UV-FLD with mass confirmation by online HPTLC-ESI-MS

A new high-throughput method is developed to quantify caffeine, ergotamine, and metamizol in a solid pharmaceutical formulation. After dissolution, the compounds are separated on silica gel 60 F(254) high-performance thin-layer chromatography (HPTLC) plates with ethyl acetate-methanol-ammonia 90:15:1 (v/v/v) as the mobile phase. Detection is performed by UV absorption at 274 nm for caffeine and metamizol, and by fluorescence at 313 /> 340 nm for ergotamine. Calibrations are linear or polynomial with determination coefficients (R(2)) >or= 0.9986. Recoveries of the three compounds are between 95% and 102% at three different concentration levels. Repeatability [relative standard deviation (RSD)] of all substances in the matrix is between +/- 0.9% and +/- 1.7%. Intermediate precision (RSD) of the three compounds range from +/- 2.0% to +/- 3.1%. Mass confirmation is performed by a single quadrupole mass spectrometry in positive electrospray ionization full scan mode for caffeine and ergotamine and in negative mode for metamizol. The results proved that this method is a simple and reliable alternative for routine analysis.     

Development and Validation of an Automated Zone Fluidics-Based Sensor for In Vitro Dissolution Studies of Captopril Using Total Error Concept

In the present research, a zone fluidics-based automated sensor for the analysis of captopril in in vitro dissolution samples is reported. Captopril is reacted under flow conditions with Ni(II) (10 mmol L⁻¹) in alkaline medium (0.15% v/v NH₃) to form a stable derivate, which is monitored spectrophotometrically at 340 nm. The chemical and instrumental parameters were carefully investigated and optimized. The validation of the developed method was performed in the range of 5 to 120% of the expected maximum concentration using the accuracy profiles as a graphical decision-making tool. The β-expectation tolerance intervals did not exceed the acceptance criteria of ±10%, which means that 95% of future results will be encompassed in the defined bias limits. The variation of the relative bias ranged between −2.3% and 3.5% and the RSD values for repeatability and intermediate precision were lower than 2.3% in all cases. The limit of detection (LOD), and the lower and the upper limit of quantification (LLOQ, ULOQ) were satisfactory and found to be 1%, 5% and 120% (corresponding to 0.6, 2.78 and 66.67 μg mL⁻¹ in dissolution medium). The developed method was successfully applied for the analysis of captopril in dissolution tests of two commercially available batches.     

Dissolution kinetics of nanodispersed gamma-alumina in aqueous solution at different pH: unusual kinetic size effect and formation of a new phase

The dissolution of a technical, nanodispersed gamma-alumina in water was studied at 25 degrees C in the pH range 3.0 < or = pH < or = 11.0. The obtained kinetic dissolution curves showed a distinct pH dependency, whereas only for pH > or = 4.5 the typical behavior of nanodispersed materials could be observed. X-ray powder diffraction analysis and nitrogen adsorption, as well as IR and UV-Raman spectroscopy, were used to characterize the solid material collected during and at the end of each dissolution experiment. As a result the formation of a new aluminum phase-bayerite-could be proven. The analysis of the equilibrium concentration enabled us to determine the solubility constant of the corresponding phase assuming a pH-dependent species distribution. The rate constants of the dissolution process were evaluated using the model of Gibbs free energy of cluster formation, which considers the size effect, among other things. As a result, we could show that the observed maxima in the concentration profiles are due to a size effect of the starting material having a primary particle radius of 10.1 nm.     

Analysis of some chlorophenoxy acids and carbamate herbicides in water and soil as amide derivatives using gas chromatography-mass spectrometry

A newly developed method for determining three phenoxy acids and one carbamate herbicide in water and soil samples using gas chromatography with mass spectrometric detection is developed. Phenoxy acids are derivatized through a condensation reaction with a suitable aromatic amine. 1,1-Carbonyldiimidazole is used as a condensation reagent. Derivatization conditions are optimized with respect to the amount of analyte, amine, solvent, and derivatization reagent. The optimum derivatization yield is accomplished in acetonitrile. 4-Methoxy aniline is used as a derivatizing agent. Obtained derivatives are stable indefinitely. Enhancement in sensitivity is achieved by using the single-ion monitoring mass spectrometric mode. The effectiveness of the developed method is tested by determining investigated compounds in water and soil samples. Analytes are concentrated from water samples using liquid-phase extraction and solid-phase extraction. Soil samples are extracted using methanol. Detection limits of 1.00, 50.00, 100.00, and 1.00 ng/mL are obtained for 2-(1-methylethoxy)phenyl methylcarbamate (Baygon), 2-(3-chlorophenoxy)-propionic acid (Cloprop), 2,4,5-trichlorophenoxyacetic acid, and 4-(2,4-dichlorophenoxy)butyric acid, respectively. LPE for spiked water samples yields recoveries in the range of 60.6-95.7%, with relative standard deviation (RSD) values of 1.07-7.85% using single component calibration curves. Recoveries of 44.8-275.5%, with RSD values ranging from 1.43% to 8.61% were obtained using a mixed component calibration curves. SPE from water samples and soil samples showed low recoveries. The reason is attributed to the weak sorption capabilities of soil and Al(2)O(3).     

Multielement analysis of coal by ICP techniques using solution nebulization and laser ablation

The combination of inductively coupled plasma atomic emission spectrometry and high resolution inductively coupled plasma mass spectrometry for the determination of 70 elements in coal were studied. Four microwave-assisted digestion procedures with different dissolution mixtures (nitric and hydrofluoric acids, aqua regia and hydrogen peroxide), lithium metaborate fusion with and without previous sample ashing as well as direct sampling by laser ablation (LA) have been tested. Examples of spectral interferences are given and different correction procedures are discussed. Detection limits in the low ng g(-1) range were obtained for most of the elements investigated by using high-purity reagents and by taking special care to prevent sample contamination during preparation. The precision was assessed from replicate analysis (including sample preparation) of coal samples and was found to be, as average values far all elements, 4-5% RSD and 10-15% RSD for procedures including sample digestion and LA sampling, respectively. The accuracy of the overall analytical procedures was estimated by analysis of certified reference materials and of a coal sample obtained from the Interlab Trace round robin test. Among the dissolution mixtures tested, the combination of nitric and hydrofluoric acids with hydrogen peroxide provide the best agreement with certified, recommended, literature-compiled or consensus values, though fusion is necessary to obtain quantitative recoveries for Si, Cr, Hf, W, Zr, Y. In general, results obtained by LA fall within +/-20% of those obtained after digestion.