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1.
Görög S 《Analytical and bioanalytical chemistry》2003,377(5):852-862
A system is proposed for the classification of related organic impurities in drugs and drug products including among others (separated and non-separated) intermediates, various kinds of by-products, among them products of different side reactions, epimeric/diastereomeric, enantiomeric impurities, impurities in natural products, and finally degradation products. Examples are taken mainly from the author's own experience and from among the named impurities in the European Pharmacopoeia with focus on impurities in hydrocortisone, prednisolone, enalapril maleate, lisinopril, ethynodiol diacetate, pipecuronium bromide, cimetidine, and ethynylsteroids. The methodological aspects of impurity profiling from the detection to the identification/structure elucidation and quantitative determination of impurities are briefly summarized.This paper is Part 23 in the series "Estimation of impurity profiles of drugs and related materials". For Part 22 see ref. [1]. 相似文献
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Aristotelis B. Syropoulos Evangelos G. Sarantonis Antony C. Calorkerinos 《Analytica chimica acta》1990
The chemiluminescent oxidation of sulphite by bromate was investigated and compared with that by cerium(IV). The reaction is sensitized by various steroid hormones which can thus be determined in the ranges 0.50–20.0μg ml 1 for cortisone; 0.50–5.00 μg ml?1 for hydrocortisone and progesterone and 0.50–6.00 μg ml?1 for testosterone and corticosterone. 相似文献
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Lu W Du L Wang M Jia X Wen J Huang Y Guo Y Gong W Bao H Yang J Sun B 《Applied biochemistry and biotechnology》2007,142(1):17-28
A new method for breeding the hydrocortisone overproducing strain Curvularia lunata by screening ketoconazole-resistance mutant was developed. A hydrocortisone overproducing mutant C. lunata KA-91 with ketoconazole-resistance marker was obtained from protoplasts treated with ultraviolet radiation. The hydrocortisone
conversion rate of C. lunata KA-91 was increased by 42.1% compared to the original strain CL-114 at the substrate 17α-hydroxypregn-4-en-3, 20-dione-21-acetate
addition concentration of 1.0 g/L. The by-products produced by KA-91 were fewer than those of the original strain. It was
assumed that the higher cytochrome P450 content of ketoconazole-resistance mutant resulted in the increase of 11β-hydroxylation
capacity. The culture conditions for biotransformation of 17α-hydroxypregn-4-en-3, 20-dione-21-acetate to hydrocortisone were
optimized by response surface methodology. Plackett–Burman design was applied to elucidate the key factors affecting the hydrocortisone
production, and the results indicated that glucose, initial pH, and glucose to total nitrogen sources ratio (ω) had significant effects on hydrocortisone production. Box–Behnken design was employed to search for the optimal parameters
of those three key factors. According to the model, the trial checking at the optimal conditions showed a high hydrocortisone
conversion rate of 82.67%. 相似文献
5.
提出了在PH10.38的碱性介质中高灵敏度测定氢化可的松的荧光光度新方法。方法灵敏度高,检出限为2.8×10^-9mol·L^-1;线性范围为5.518×10^-9-3.862×10^-6mol·L^-1。应用本法测定注射液中氢化可的松,平均回收率为99.3%,结果令人满意。 相似文献
6.
Joaquim C. G. Esteves da Silva Jos R. M. Dias Jú lia M. C. S. Magalh es 《Analytica chimica acta》2001,450(1-2):175-184
A chemiluminescent flow system for bromate detection, based on the reaction of bromate with sulphite in acid medium and using the steroid hydrocortisone as sensitiser, was studied. A factorial analysis strategy for the study of the effect on the system response of the experimental factors, flow rates of two pumps (Q1 — acid sulphite plus hydrocortisone aqueous solution; Q2 — carrier, water), sample injection volume (VL), reactor volume (VR), sulphite concentration (CS), hydrocortisone concentration (CH) and acid concentration (CA), was used. Screening analysis of the system performance was made using Plackett Burman designs. The system optimisation procedure was achieved by three levels three factors full factorial designs. VL and CH are the most significant factors — a quadratic CH term was also observed to be significant. The optimised system responded linearly (logarithm of the detector signal as function of the logarithm of the bromate concentration) in the concentration range between 3.6×10−7 and 5.0×10−4 M with a limit of detection of about 8.0×10−8 M (about 10 microg/l). An analysis of some interfering ions was made and it was suggested that bromide and chloride begin to quench chemiluminescence when they are in a 10-fold excess relatively to bromate concentration. 相似文献
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《Analytical letters》2012,45(9):817-833
Abstract A novel spectrophotometric method for the assay of δ4 -3-Ketosteroids in formulations is presented. Oxalyldihydrazide in methanol reacts selectively with δ4-3-Ketosteroids at pH 2 forming stable hydrazones which exhibit intense absorption specta at 300 nm. and high molar absorpitivities ranging from 14480–18750 for most steroids studied. Methyltestosterone showed exception ally high sensitivity where its molar absorpitivity was 21630. As little as 5–30 μg steroid were determined with 99.28 ± 0.65–100.16 ± 0.94% accuracy. The method was applied successfully to the micro-determination of cortisone, hydrocortisone, hydrocortisone acetate, norethisterone, norethisterone acetate, norgestrel and methyltestosterone in substance as well as in different pharmaceutical dosage forms. The precision of assay was compareble with existing spectrometric methods for ketosteroid drugs. The method is simple, accurate mean - while selective and more sensitive than the INH-method. 相似文献
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在一片聚甲基丙烯酸甲酯(PMMA,50mm×40mm×3mm)上用激光雕刻机雕刻一条宽200μm,深100μm,长9 cm的蜿蜒形流通池,其上盖以另一片大小相同的PMMA并在1.6MPa压力和108℃温度条件下使之结合成一体,从而制成了微流动注射芯片。基于氢化可的松对鲁米诺-铁氰化钾化学发光体系的增敏作用,提出了微流动注射芯片-化学发光法测定氢化可的松含量的方法。当化学发光体系中鲁米诺的浓度为8.0×10~(-5)mol·L~(-1)、铁氰化钾浓度为4.0×10~(-5)mol·L~(-1)、体系的pH值为12时,氢化可的松发光强度的增加值与其质量浓度在8.0×10~(-5)~8.0×10~(-2)g·L~(-1)范围内呈线性关系,检出限(3S/N)为4.0×10~(-5)g·L~(-1)。方法应用于食品中氢化可的松残留量的测定,回收率在96.5%~104.0之间。 相似文献
10.
Electrochemical sensor employing edge-plane pyrolytic graphite electrode (EPPGE) for the sensitive detection of hydrocortisone (HC) is delineated for the first time. The electrochemical properties are investigated exercising the cyclic voltammetry and square-wave voltammetry (SWV). When equating with the bare basal-plane pyrolytic graphite electrode (BPPGE), the EPPGE gave better response towards the detection of HC both in terms of sensitivity and detection limit. The voltammetric results indicated that EPPGE remarkably enhances the reduction of HC which leads to considerable amelioration of peak current with shift of peak potential to less negative values. The difference in the surface morphology of two electrodes has been studied. Also, the EPPGE delivered an analytical performance for HC with a sensitivity of 45 nA nM−1 and limit of detection of 88 nM in the concentration range 100-2000 nM. The method has been utilized for the determination of HC in pharmaceuticals and real samples. The electroanalytical method using EPPGE is the most sensitive method for determination of HC with lowest limit of detection to date. The major metabolites present in blood plasma did not intervene with the present investigation as they did not exhibit reduction peak in the experimental range used. A comparison of results with high performance liquid chromatography (HPLC) signalizes a good agreement. 相似文献