Optimization and validation of stability indicating RP-HPLC method for the quantification of gefitinib in bulk drug and nanoformulations: An application towards in vitro and ex vivo performance evaluation

Gefitinib (GFB) is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor used primarily to treat non-small cell lung cancer (NSCLC), but it also works by lowering AKT and MAPK phosphorylation, which makes it effective against the breast cancer cells. A high-performance liquid chromatography (HPLC) method was developed for detecting gefitinib by C18 analytical column with mobile phase containing acetonitrile and 1 % w/v ammonium acetate in water with ratio of 60:40. Box-Behnken design was used to optimize the chromatographic conditions, and method was validated for accuracy, precision, linearity, robustness, ruggedness, limit of detection, and limit of quantification. The developed method was found to be useful in estimating gefitinib in conventional marketed tablet dosage forms and nanoformulations such as SLNs and liposomes. With a calibration curve, linearity was attained in the drug concentration range of 8–56 µg/mL (r² = 0.9996), and sensitivity was found to be 1.3 and 3.9 µg/mLas LOD and LOQ, respectively. All the validation criteria for the method were within the acceptable limits. The drug content in the conventional tablet formulation was found to be 99.99 %. The HPLC analysis indicated that gefitinib was highly soluble in Precirol ATO5 as solid lipid and tween 80 as surfactant. Drug entrapment efficiency was found to be 83.1 % and 80.5 % for SLNs and liposomes respectively. In vitro release data revealed that 30 % of drug was released from plain suspension and more than 77 % released from both nanoformulations after 24 h at pH 7.4 respectively. By applying kinetic fit, data was most appropriately fitted into first order as compared to other. The apparent permeability of gefitinib from plain suspension, SLNs and Liposomes was found to be 3.98 × 10^?4 cm/min, 1.35 × 10^?4 cm/min and 1.79 × 10^?4 cm/min.     

粉末压片-X-射线荧光光谱法分析砂岩型铀矿制样中粘结剂用量的探讨

由于砂岩型铀矿的成矿特性,样品粉末的内聚力小,采用直接压片法有时难以成型,样片表面常见裂纹,上机测量易碎裂。混合压片法适应性强,制样成功率高,但常见的问题是样品经粘结剂稀释会影响元素的检出限及结果的准确性。本文对粉末压片-X射线荧光光谱法测定砂岩型铀矿地质样品时,前期制样中添加粘结剂的比例进行了研究。试验按照不同比例在铀矿石标准物质GBW04101、GBW04102中添加粘结剂,在扫描电镜下观察到随着粘结剂用量的增加样片表面的光滑度及致密度都呈上升趋势,在X-射线荧光光谱仪上对主量元素进行测定后发现X射线强度在粘结剂添加量大于0.2 g时明显下降,经与GBW04101、GBW04102标准值进行对比后优选出粘结剂与样品的最佳比例为1：20,在此比例下制成的样片光滑平整,不易碎裂,用粉末压片-X射线荧光光谱法进行测定,标准物质测定结果的相对误差为0.56%～6.76 %,相对标准偏差(RSD,n=12)为0.013 %～7.68 %,均达到了《地质矿产实验室测试质量管理规范》DZ/T 0130-2006的要求。本文为粉末压片-X射线荧光光谱法分析砂岩型铀矿地质样品提供了可靠的实验参考依据。     

仲景胃灵片中芍药苷的含量测定

采用SPE -高效液相色谱法测定仲景胃灵片中芍药苷的含量 ;以甲醇 -水 (体积比30∶70)为流动相 ,IntersilODS(3)柱 (250mm×4.6mm ,5μm)为固定相 ,流速为1mL/min,检测波长为230nm ;芍药苷的测定在11.55～92.40mg/L范围内线性关系良好 ,平均回收率为99.9% ,RSD为1.6% ;方法简单 ,灵敏度高 ,可用于仲景胃灵片中芍药苷的含量测定。     

复方新诺明片剂中有效成分的毛细管区带电泳快速测定法

研究了用毛细管区带电泳法快速测定复方新诺明片中磺胺甲恶唑（ＳＭＺ）和甲氧苄氨嘧啶（ＴＭＰ）的含量。使用长２７ｃｍ（有效长度２０ｃｍ）内径５０μｍ的石英毛细管,２５ｋＶ分离电压,在０．０５ｍｏｌ／Ｌ的乙酸盐缓冲液（ｐＨ５．５）中,上述两组分可在１．５ｍｉｎ内完全分离。用紫外检测器在２１４ｎｍ处检测,外标法定量。１０次检测含有１４１．７ｍｇ／ＬＳＭＺ和２５．６ｍｇ／ＬＴＭＰ的试样溶液,相对标准偏差为１     

Capillary electrophoresis fingerprinting coupled with chemometrics to evaluate the quality consistency and predict the antioxidant activity of Sanhuang tablet as part of its quality control

A capillary electrophoresis fingerprint was constructed for Sanhuang tablet, a Chinese traditional patent medicine, that was commonly used in clinical practice, where the isosceles trapezoid method was first applied for the optimization of background electrolyte solution, and the resolution index was performed to assess the experimental conditions; furthermore, a novel linear quantitative fingerprint method was established for accurate qualitative and quantitative discrimination of the test samples from diverse commercial brands. The fingerprint analysis coupled with quantitative determination of two components was employed to elucidate that the quality consistency of the products was relatively good within one manufactory, but poor among different companies for the 30 batches of samples. In addition, the fingerprint–efficacy relationship between chemical components and antioxidant activity in vitro was investigated using partial least squares analysis, and the calibration and prediction of the antioxidant activity of the selected samples via fingerprint data were presented with the desired results. This work illustrates that the proposed fingerprint analysis based on linear quantitative fingerprint method can be applied for the quality evaluation of traditional Chinese medicine and herbal preparations as part of their quality control, and the constructed mathematical model is particularly suitable for depicting the fingerprint–efficacy relationship.     

芦丁对罗丹明6G的荧光猝灭机理研究及其含量测定

根据Stem - Volmer方程和罗丹明6G吸收光谱的变化研究了芦丁对其荧光猝灭的类型及机理,结果表明,芦丁与罗丹明6G作用,形成一种稳定的复合物,而发生荧光静态猝灭,求得复合物的结合常数K=5.55×105L/mol,结合点数n=1.26.芦丁含量在0.92～137.8μg/mL范围内与F0/F成正比,检出限为0....     

单扫描极谱法测定复方青黛片中的吲哚醌

应用单扫描极谱法(LSV)及循环伏安法(CV),在pH 9.8的氨性缓冲液中,对2,3-吲哚醌(ISA)的电化学行为进行了研究。在该缓冲液中ISA产生p1、p2两个还原峰,峰电位分别为-0.51 V和-0.59 V(vs.SCE)。其中p1峰峰电流i″p值与ISA的浓度在2×10-6~2×10-4mol.L-1范围内呈线性关系(r=0.999 5)。检出限为7×10-7mol.L-1,对浓度为4×10-5mol.L-1的ISA溶液进行11次平行测定,RSD为1.29%。所建立的方法已用于复方青黛片中ISA含量的测定。     

荧光猝灭法测定维生素C片和果汁饮料中抗坏血酸的含量

罗丹明B溶液在激发波长(λex)为365nm时,在发射波长(λem)580nm处有最大荧光发射强度。如向罗丹明B溶液中加入碘溶液(I3-),由于两者之间反应生成缔合物而使其荧光猝灭,但罗丹明B发射荧光的峰位未变。如在此猝灭反应之前加入一定量的抗坏血酸(AA),则上述猝灭作用由于I3^-被AA还原而失效,使荧光得以重现。进一步试验表明,在总体积为50mL中,1×10^-3 mol·L^-1碘溶液为2.0mL,1.0×10^-4 mmol·L^-1罗丹明B溶液为5.00mL,pH 4.7的乙酸-乙酸钠缓冲溶液为5.0mL,在常温下反应10min的条件下,抗坏血酸的浓度在40μmol·L^-1内与其对应的荧光强度之间呈线性关系(注:抗坏血酸反应在碘溶液及罗丹B溶液之前加入),其检出限(3s/k)为5.6×10^-9 mol·L^-1。根据以上事实,提出了应用上述荧光猝灭法间接测定维生素C片剂及注射液中抗坏血酸的含量。分析时取片剂样品5片,研磨混匀后称取25.0mg溶于水中,并定容至250.0mL,取1.00mL溶液按上述方法测定。注射液样品则取0.10mL,加水定容至250.0mL,取1.00mL溶液进行测定。在实际样品基础上进行加标回收试验,测得回收率为97.4%(片剂)和98.4%(注射液),测定值的相对标准偏差(n=6)依次为2.3%,1.7%。还应用此方法测定了3种果汁饮料,所测得结果与用碘量法校对的结果相符。     

毛细管区带电泳法测定复方芦丁片中芦丁和维生素C的含量

考察了缓冲溶液的pH、背景电解质浓度及分离电压对芦丁、维生素C及苯甲酸分离的影响，建立了以苯甲酸为内标，毛细管区带电泳法快速测定复方芦丁片中芦丁和维生素C含量的新方法。以3g/L硼砂－4g/L硼酸(pH8.18）为运行缓冲液，苯甲酸为内标，在分离电压为25kV，检测波长为254nm的电泳条件下，芦丁、维生素C和内标可在5min实现分离。芦丁的线性方程为：y=2．65x＋0．095（r＝0．9994），线性范围为0．025mg/mL－0．4mg/mL，维生素C的线性方程为：y＝3．1343x＋0．565（r＝0．9991），线性范围0．125mg/mL－1．0mg/mL。方法可用于复方芦丁片的质量控制。     

化学计量学法辅助紫外分光光度法同时测定小儿复方苯巴比妥片剂中四组分的研究

在质量浓度为 0 .5g/L的酒石酸乙醇溶液中 ,阿司匹林、非那西汀、咖啡因和苯巴比妥的 λmax分别为 2 2 9、2 50、2 2 9、2 65、2 2 5nm,表明吸收光谱严重重叠。在相应的 λmax处 ,其表观摩尔吸光系数分别为 5.61× 1 0 3、7.48× 1 0 3、6.1 5× 1 0 3、7.89× 1 0 3以及 4.35× 1 0 3L· mol-1· cm-1。用偏最小二乘法和迭代目标转换因子法等化学计量学法辅助紫外分光光度法 ,不经分离 ,同时测定了模拟样和小儿苯巴比妥片剂试样中的上述四组分。虽然体系的加和性较差 ,但由于两算法抗交互作用和抗随机误差的能力较强 ,故仍取得了满意的结果。可用于复方药物质量的监控