Retention Data for Some Statin-Type Antihyperlipidemic Drugs in Normal-Phase TLC

JPC – Journal of Planar Chromatography – Modern TLC - The normal-phase thin-layer chromatographic behavior of five statin-like drugs — atorvastatin, cerivastatin, fluvastatin,...     

The Retention Behavior of Some Atypical Antipsychotic Drugs in Normal-Phase TLC

JPC – Journal of Planar Chromatography – Modern TLC - Chromatographic behavior in normal-phase thin-layer chromatog-raphy has been investigated for six atypical antipsychotic drugs...     

Reversed-Phase Ion-Pair Chromatography Of Antihistamine Drugs

Abstract

A reversed-phase ion-pair chromatographic separation of some antihistamine drugs is presented. The stationary phase consists of 1-pentanol or methylene-chloride adsorbed on a CH-10 column and the mobile phase of a phosphate buffer containing cyclohexylsulphamate and dimethyl-octylamine. It is concluded that this method is a valuable complement to a partition chromatographic method reported in an earlier publication.     

Reversed-Phase Chromatographic Retention Behavior of Some Fibrate-Type Antihyperlipidemic Drugs

JPC – Journal of Planar Chromatography – Modern TLC - Relationships between RM values and mobile phase composition have been examined for six fibrate-type drugs–bezafibrate,...     

Liquid Chromatographic Analysis of Antiepileptic Drugs: An Overview

Abstract

Extraction of antiepileptic drugs (AEDs) can be carried out by different procedures which include: (i) protein precipitation, (ii) liquid-liquid and (iii) liquid-solid extraction. The latter yields a cleaner sample and shows efficiency comparable to the other procedures; recovery ranges from 90 to 105% for most AEDs.

Types of column include: (i) conventional, (ii) microbore and (iii) high-speed. Compared with conventional and high-speed columns, microbore columns, which have a diameter of 1–2 mm, allow to achieve the highest sensibility (up to double values) and to reduce solvent consume (up to 70 %). High-speed columns, characterized by a length of 3–10 cm and by a reduced packing particle size (? 3μm), make the analysis time more rapid by at least 50%.

Reversed phase chromatography is the most versatile technique as compared to the normal phase and to the precision and accuracy. These parameters, in fact, resulted close to those of the fluorescence polarization immunoassay technique (FPIA), which was the most precise and accurate among the methods compared (79).     

The Normal-Phase Retention Behavior of Some Angiotensin-II Receptor Antagonists

JPC – Journal of Planar Chromatography – Modern TLC -     

Planar Chromatographic Systems in Pattern Recognition and Fingerprint Analysis

An overview of opportunities of contemporary planar chromatography in pattern recognition and fingerprint analysis is presented. The most used chemometric methods are highlighted and their main advantages and drawbacks are underlined. In addition a cross section of the application of planar chromatographic fingerprinting in food, pharmaceutical, environmental, and forensic analysis is given.     

Liquid Chromatographic Analysis of Some N-Alkyl-3,4-methylenedioxyamphetamines

Abstract

The liquid chromatographic separation of a series of low molecular weight N-alkyl derivatives of 3,4-methylenedioxyamphetamine (MDA) is reported. The N-methyl-, N-ethyl- and N,N-dimethyl-derivatives of MDA have appeared as street drugs in recent years. These compounds are becoming significant forensic problems due to their unique pharmacological properties and relative ease of chemical synthesis. These amines were synthesized via reductive amination of the corresponding ketone with alkylamines. The UV absorption spectra for these compounds produced almost equally intense absorbance at 234 and 285 nm. The compounds were separated by reversed-phase (C₁₈) HPLC procedures using a mobile phase of aqueous methanol at low pH.     

Chromatographic Analysis of New Antidepressant Drugs by Normal- and Reversed-Phase TLC

JPC – Journal of Planar Chromatography – Modern TLC - The selectivity of the TLC separation of six new antidepressant substances has been investigated on silanized silica gel C18 and on...     

Solvent Selectivity in Normal-Phase TLC

JPC – Journal of Planar Chromatography – Modern TLC - The role of the mobile phase in controlling selectivity for adsorption chromatography–with either thin-layer plates or...     

Normal-Phase TLC Separation of Some Antiarrhythmics. Densitometric Determination of Mexiletine Hydrochloride in Capsules

JPC – Journal of Planar Chromatography – Modern TLC - A normal-phase (NP) TLC method has been established for separation of the five antiarrhythmics - disopyramide, flecainide,...     

Flow Injection Analysis of Some Phenolic Sympathomimetic Drugs

ABSTRACT

A new, rapid and economical flow-injection (FI) method for deter-mining some phenolic sympathomimetic drugs is proposed. These drugs are etilefrine hydrochloride (ET), fenoterol hydrobromide (FT), hexoprenaline sulphate (HP), orciprenaline sulphate (OP) and reproterol hydrochloride (R.T). The determination is based on the reaction of the studied phenolic sympathomimetic drugs with 4-aminoantipyrine (4-AAP) and potassium hexacyanoferrate (III). The chemical reaction variables and also the FI variables, were optimized on the basis of sensitivity, sampling rate and reagent consumption. The proposed technique was applied to the analysis of pure raw materials in concentrations ranging from 2-20 μg.ml^?1 in case of ET, 4-30 μg.ml^?1 in case of FT and OP and from 8-50 μg.ml^?1 in case of HP and RT. Samples can be introduced at rates of about 130 per hour. The suggested procedure retained its accuracy and precision when applied to the analysis of pharmaceutical dosage forms containing the corresponding drugs, as judged by the RSD (%) and students' test. The results of the analysis were found to agree statistically with those obtained by applying either the official or the referee methods. Furthermore, the validity of the results was assessed by applying the standard addition technique.     

Analysis of Some Fibrate-Type Antihyperlipidemic Drugs by AMD

JPC – Journal of Planar Chromatography – Modern TLC - Conditions have been established for separation of six fib rate drugs by automatic multiple development (AMD). The best system was...     

Spectroscopic Studies of the Complexation of Iodine with Antihistamine Drugs in Solvents of Varying Relative Permittivity

The interaction of oxatomide (OXA), azacyclonol (AZA) and chloropheniramine (ClPA) antihistamine drugs with iodine was studied spectrophotometrically in different solvents and at three different temperatures. The electronic, FT-IR, far-IR, and mass spectra of the resulting charge-transfer (CT) complexes were recorded, in addition to thermal analysis. The results obtained show that the stoichiometries of the reactions are all 1:1. The observed time dependence of the CT band and subsequent formation of $ {\text{I}}_{3}^{ - } $ in solution were related to the slow transformation of the initially formed 1:1 (donor: I₂) outer complex to an inner complex (electron donor?Cacceptor), followed by a fast reaction of the inner complex with iodine to form a triiodide ion. The characteristic strong absorptions of $ {\text{I}}_{3}^{ - } $ are observed around 360?nm. The CT-complexes have the formulae [(OXA)I]⁺ $ {\text{I}}_{3}^{ - } $ , [(AZA)I]⁺ $ {\text{I}}_{3}^{ - } $ and [(ClPA)I]⁺ $ {\text{I}}_{3}^{ - } $ . The formation constants (K), molar absorption coefficients (?? _CT), and thermodynamic parameters ??H ^#, ??S ^# and ??G ^# of these interaction have been determined and discussed.     

中成药中违禁添加药物的液质联用仪测定研究

近年来不断有关于保健食品或植物提取药物中违禁添加合成药物的相关报道,其中包括各类兴奋剂、利尿剂、壮阳剂、厌食剂等几十种药物,为保护广大消费者的身体健康,有关国家都建立了相关的技术标准。在这一分析过程中,需要解决3个方面问题,一是药物的分析范围非常大,尤其是在极性、酸碱性差异非常大,如何能达到一次分析完成全谱的分析工作;二是药物含量限制差异巨大,有的仅有几个mg/kg;三是如何能准确地完成定性结论。我们依据相关国外实验标准,采用Waters的QuattroLC系统结合Waters的SymmetryC18色谱柱,非常好地建立了一个完整的相应的违禁药物分析系统。     

Chromatographic Separation of Some Inorganic Isomers

Abstract

Isomeric simple complexes of Ti (III) and Hg(II) with p-diethylaminoanil of anthraceneglyoxal (DEAAnG) and isomeric mixed ligand complexes of Zn (II) with DEAAnG and Thiourea (TU) have been synthesized, resolved in bulk on silica gel column, and characterized on the basis of elemental analyses, molar conductance and infrared studies.

Binary mixtures of isomers have been analysed by TLC, PC and EC techniques. TLC method showing highest resolving capacity was used in the quantitative analysis of isomeric mixtures. Resolved isomers were identified using i.r. and migration rate correlations.     

几个超分子体系中非常规键的AIM分析

对五个含氟分子自组装形成的晶体进行了AIM (Atoms in Molecules)分析, 观察到、并定量地描述了这些晶体中大量存在的氟原子相关的非常规弱相互作用力; 并且找到一个完全由F…O弱相互作用主导的超分子自组装晶体.     

Testing for Drugs in Hair – a Review of Chromatographic Procedures

This article reviews the analysis of drugs and drug metabolites in hair by chromatographic procedures, including the pretreatment steps, and the extraction methods. The general tendency in the last years, to highly sophisticated techniques (GC–MS–NCI, HPLC–MS, GC–MS–MS) illustrates the constant fight for sensitivity.