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Liquid chromatographic enantioseparation, determination, bioassay and isolation of enantiomers of Ketorolac : a review

100%

Bhushan R.

Acta Chromatographica

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2022

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tom Vol. 34, no. 3

220--236

EN

Ketorolac (Ket) is a potent non-narcotic analgesic drug (among the nonsteroidal anti-inflammatory drugs). The physiological activity of Ket resides with (S)-(-)-Ket while the drug is marketed and administered as a racemic mixture. Therefore, it is desirable that the pharmacokinetics is measured and quantified for enantiomers individually and not as a total drug. The present paper is focused on relevant literature on LC enantioseparation of (RS)-Ket along with bioassay, pharmacokinetic and clinical studiem within the discipline of analytical chemistry. HPLC and Thin layer chromatography (TLC) methods using both direct and indirect approaches are discussed. The methods provide chirality recognition even in the absence of pure enantiomers. Besides, a brief discussion on resolution by crystallization and enzymatic methods is included. The most interesting aspects include establishment of structure and molecular asymmetry of diastereomeric derivatives using LC-MS, proton nuclear magnetic resonance spectrometry, and by drawing conformations in three dimensional views by using certain software. A brief discussion has also been provided on the recovery of native enantiomers by TLC.

2

Chromatographic methods and approaches for bioequivalence study, drug screening and enantioseparation of indapamide

51%

Sethi S. , Martens J. , Bhushan R.

Acta Chromatographica

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2024

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tom Vol. 36, no. 2

67--85

EN

Indapamide (Indp) and certain other diuretics have been abused in sports, therefore, having sensitive methods for its detection and assay in biological fluids (whole blood, plasma, serum, and urine) is of significant importance. The racemic mixture of Indp is being used as an active pharmaceutical ingredient among other commonly prescribed diuretics. The regulatory authorities and pharmaceutical industries demand analytical methods for successful enantioseparation of such molecules. The paper presents a critical overview of the scientific issues of the application of contemporary techniques involving various chromatographic approaches (with liquid or supercritical fluid as mobile phases) and capillary electrophoresis and method development, for drug screening, assay, bioequivalence studies and enantioseparation of indapamide with their results. It also covers the historical developments that led to significant breakthroughs in research and concise evaluations of research in the area. Different types of chromatographic methods (HPLC, CEC, SFC etc) discussed herein provide an insight and a choice to select a method to (i) screen Indp for drug abuse, (ii) separate, isolate and quantify the enantiomers of Indp and (iii) investigate their pharmacokinetics as markedly different species and not as a total drug. The article evaluates the field’s status with a broad base and practical oriented approach so that the underlying principles are easily understood to help chemists and nonspecialists gain useful insights into the field outside their specialization and provide experts with summaries of key developments. To the best of authors’ knowledge there has been no attempt to review such methods for analysis of Indp and this is the first report of its kind.

3

Paleoclimatic analysis of Quaternary sediments associated with the floodplain deposits of a tropical estuary along the southwestern cost of India

38%

Murali D. , Reghunath R. , Prakash P. , Bhushan R. , Krishnan K. A. , Baby S. R.

Studia Quaternaria

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2024

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tom Vol. 41, Nr 1

13--21

EN

The coastal regions of southwest India which falls in the tropical regime, have witnessed many transgression-regression events and climatic extremes in the Quaternary Period. A core, 15 m long, was recovered from the floodplains associated with a typical backwater body (lake) in the southwestern coast of India. The granulometric analysis proved dominance of sand and silt fractions and extremely high energy conditions over the entire core. The TOC/TN ratio indicated a domination of the C4-type over the C3-type plants in the lower half of the core, suggesting a warm climate. The C3-type plants prevail in the upper part of the core, thus reflecting cool and wet environments. Extremely low values of TOC/TN ratio (0.33% to 10%) of the core indicate short periods of very high rainfall events and the rapid influx of nutrients to the basin and the eutrophication of the basin. The presence of slightly brackish, brackish/marine and marine benthic foraminifers at 12.5–9 m depth indicates episodes of transgression and regression. The derived AMS radiocarbon dates suggest the Marine Isotope Stage 3 for the lower part of the core.