Structure–Retention Correlation of Some Oxicam Drugs in Reversed‐Phase Liquid Chromatography

David, Víctor; Albu, Florin; Medvedovici, Andrei

doi:10.1081/jlc-120030172

Cited by 16 publications

(11 citation statements)

References 15 publications

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“…Chromatographic elution was achieved with methanol, acetonitrile or both as organic modifiers, while the aqueous component was always a buffer solution with pH around 3. In a previous paper [6] it was pointed out that meloxicam and piroxicam are involved in ketoenolic equilibrium characterized by a significant acidity constant (pK a is close to the value of 3). Therefore, at such value of pH in the aqueous component, the retention of both analytes is highly influenced by low variation of the parameter, resulting in a reduced robustness of the method.…”

Section: Introductionmentioning

confidence: 99%

“…All of them are based on reversed-phase liquid chromatography and UV detection [3−6], using different columns and mobile phase compositions. One of the methods uses mass spectrometry as a detection system, for improving the sensitivity of determination of this drug [6]. Sample preparation was achieved in different ways: extraction with chloroform [3,4], or plasma deproteinization with acetonitrile [5].…”

Section: Introductionmentioning

confidence: 99%

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A Non-extracting Procedure for the Determination of Meloxicam in Plasma Samples by HPLC-Diode Array Detection

Medvedovici

Albu²,

Georgita³

et al. 2011

Arzneimittelforschung

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The bioequivalence of two formulations of 15 mg tablets of meloxicam (CAS 71125-38-7), Meloxicam (LaborMed Pharma) and a commercially available preparation as reference in 24 healthy male and female Caucasian volunteers was assessed based on a validated non-extractive HPLC-DAD method. The sample preparation procedure was based on protein precipitation with a mixture of methanol/acetonitrile, trifluoacetic acid and sodium sulfate solution. Piroxicam (CAS 36322-90-4) was used as internal standard. The stepwise gradient elution profile of the chromatographic method allows injection of a high volume of the sample (500 microL) with the focusing of both analytes in a Chromolith Performance RP-18e column. The mobile phase constituents are methanol and aqueous 20 mmol/L Na2HPO4 buffer solution brought to pH = 6 with H3PO4. A flow-rate of 2 mL/min achieves a complete chromatographic run (including column equilibration) within 12 min. UV detection at 356 nm allowed a quantitation limit around 30 ng/mL. Bioequivalence study was based on an open-label, randomized, two-period, two-sequence, single dose, crossover design with a 2-week wash-out period between consecutive oral administrations. The main pharmacokinetic parameters (C(max), t(max), t 1/2, AUD and AUC(0-infinity)) were considered as evaluation criteria for the bioequivalence of the test drug against the reference.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Non-extracting Procedure for the Determination of Meloxicam in Plasma Samples by HPLC-Diode Array Detection

Medvedovici

Albu²,

Georgita³

et al. 2011

Arzneimittelforschung

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“…According to a previous work, pK a values for tenoxicam and piroxicam are 5.3 and 4.6, respectively [27]. The aqueous component of the mobile phase (containing 0.1% H 3 PO 4 ) has a pH value around 2.5, forcing the analytes to elute as undissociated structures.…”

Section: Chromatographic Methodsmentioning

confidence: 98%

Fast RPLC-UV method on short sub-two microns particles packed column for the assay of tenoxicam in plasma samples

Sora¹,

Galaon²,

Udrescu³

et al. 2007

Journal of Pharmaceutical and Biomedical Analysis

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“…So far, in RPLC, the stationary phase has been considered the only partner involved in hydrophobic interactions with analytes and organic modifiers [4,5]. However, the intrinsic hydrophobic characteristic of a stationary phase is rather difficult to be measured quantitatively [6], although several practical models have been already accepted for estimation [7 -9].…”

Section: Introductionmentioning

confidence: 99%

Competitional hydrophobicity driven separations under RP‐LC mechanism: Application to sulfonylurea congeners

David¹,

Galaon²,

Caiali

et al. 2009

J of Separation Science

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Retention of a model set of sulfonylurea compounds has been studied under RP-LC conditions, considering competitional effects brought by different alcohols (ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol, and 1-octanol) used as additives in the organic component of the mobile phase (methanol). The capacity factors determined for the model compounds decreased with the increase of the hydrophobic character of the organic additive in the mobile phase. The amount of the additive within the organic component of the mobile phase was kept constant (1% as volumetric ratio). Retention was studied at different mobile phase compositions (aqueous to organic component ratios). Different functional fitting models were used to correlate retention to the content of the organic component in the mobile phase. Extrapolation of retention expressed as capacity factor to a mobile phase composition free of organic component is well correlated to the hydrophobic characteristics of the organic additives. The adsorption model was used for tuning the experimental find-outs. The possibility of controlling retention through the competitive effects induced by hydrophobic additives in the mobile phase is highlighted.

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Structure–Retention Correlation of Some Oxicam Drugs in Reversed‐Phase Liquid Chromatography

Cited by 16 publications

References 15 publications

A Non-extracting Procedure for the Determination of Meloxicam in Plasma Samples by HPLC-Diode Array Detection

A Non-extracting Procedure for the Determination of Meloxicam in Plasma Samples by HPLC-Diode Array Detection

Fast RPLC-UV method on short sub-two microns particles packed column for the assay of tenoxicam in plasma samples

Competitional hydrophobicity driven separations under RP‐LC mechanism: Application to sulfonylurea congeners

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