Novel type of flow injection immunoassay for the determination of phenytoin in serum

Bereczki, Andrea; Horváth, Viola

doi:10.1016/s0003-2670(99)00205-6

Cited by 14 publications

(8 citation statements)

References 27 publications

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“…Although this method does require appropriate antibodies and labeled analogs for the drug or analyte of interest, this is not a major limitation since these reagents can be obtained or modified from those used for the same analytes in other types of immunoassays. These properties should make the UFIDA method useful in a variety of areas, including therapeutic drug monitoring, pharmacological studies, and measurements of drug-protein binding [1,2,5,6,[13][14][15]20,21,27,56,57]. (a) General scheme for an ultrafast immunoextraction/displacement assay (UFIDA) and (b) a typical chromatogram for such an assay.…”

Section: Discussionmentioning

confidence: 99%

“…Phenytoin is an anti-epileptic drug that has significant binding in blood [6,7]. This drug is mainly bound in blood to the protein human serum albumin (HSA), with approximately 90% of phenytoin being complexed at therapeutic levels in adults [8][9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

“…There have been numerous methods developed for the measurement of phenytoin's free fraction in blood, plasma or serum [6,10,12,[15][16][17][18][19][20][21][22]. Examples include techniques based on equilibrium dialysis, ultrafiltration, and restricted access media (RAM) columns [6,10,14,15,18,19,21].…”

Section: Introductionmentioning

confidence: 99%

“…Examples include techniques based on equilibrium dialysis, ultrafiltration, and restricted access media (RAM) columns [6,10,14,15,18,19,21]. Other techniques such as CE can also be used to examine drug-protein interactions in standard solutions [23][24][25][26], but many of these methods are not applicable for work with the small free fractions of drugs or the complex matrices that are found in clinical samples.…”

Section: Introductionmentioning

confidence: 99%

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Analysis of Free Drug Fractions Using Near-Infrared Fluorescent Labels and an Ultrafast Immunoextraction/Displacement Assay

2006

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A chromatographic method was developed for measuring free drug fractions based on the use of an ultrafast immunoextraction/displacement assay (UFIDA) with near-infrared (NIR) fluorescent labels. This approach was evaluated by using it to determine the free fraction of phenytoin in serum or samples containing the binding protein human serum albumin (HSA). Items considered in the design of this method included the dissociation rate of HSA-bound phenytoin, the rate of capture of free phenytoin by immunoextraction microcolumns, the behavior of NIR fluorescent labels in a displacement format, and the overall response and stability of the resulting assay. In the final UFIDA method, the free fraction of phenytoin was extracted in approximately 100 ms by a microcolumn containing a small layer of anti-phenytoin antibodies. This gave a displacement peak for a NIRfluorescent labeled analog of phenytoin that appeared within 2−3 min of sample injection, creating a signal proportional to the amount of free phenytoin in the sample. The UFIDA method provided results within 1−5% of those determined by ultrafiltration for reference samples. The lower limit of detection was 570 pM and the linear range extended up to 10 μM. This approach is not limited to phenytoin but can be adapted for other analytes through the use of appropriate antibodies and labeled analogs.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Analysis of Free Drug Fractions Using Near-Infrared Fluorescent Labels and an Ultrafast Immunoextraction/Displacement Assay

2006

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“…5,6 Many techniques have been developed for antiepileptic analysis, including high-performance liquid chromatography, [7][8][9][10][11][12] gas chromatography, 13 supercritical fluid chromatography, 14 multivariate spectrometry, 15 and inmunochemical techniques. [16][17][18] Now, due to its different separation mode and much faster analysis times, capillary electrophoresis is widely accepted as a powerful new tool for drug analyses. In fact, phenobarbital has been analysed by capillary zone electroforesis (CZE) and micellar electrochromatography (MECC).…”

Section: Introductionmentioning

confidence: 99%

Capillary Zone Electrophoresis Analysis of Anti-Epileptic Drugs

Luis

Blanco

Arias

et al. 2001

Journal of Liquid Chromatography & Related Technologies

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This paper describes the development of a simple, reliable, reproducible, and fast method, based on capillary zone electrophoresis with diode array detection, for the separation and determination of two antiepileptic drugs. Phenytoin (DPH) and phenobarbital (PB) were separated in 4 min by using a carrier containing glycine 50 mM, pH 10.5. The limit of detection was 0.1 µg mL -1 for both compounds. Satisfactory reproducibility was obtained for migration times (<1.4%) and corrected peak areas (<6.9%) in the analysis of pharmaceutical formulations. The average recoveries obtained, which ranged between 100 and 108%, testify to the accuracy of the proposed method.

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Labeling strategies for bioassays

Hempen

Kärst

2005

Anal Bioanal Chem

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Different labeling strategies for enzymatic assays and immunoassays are reviewed. Techniques which make use of direct detection of a label, e.g. radioimmunoassays, are discussed, as are techniques in which the label is associated with inherent signal amplification. Examples of the latter, e.g. enzyme-linked immunosorbent assays or nanoparticle-label based assays, are presented. Coupling of the bioassays to chromatographic separations adds selectivity but renders the assays more difficult to apply. The advantages and drawbacks of the different analytical principles, including future perspectives, are discussed and compared. Selected applications from clinical, pharmaceutical, and environmental analysis are provided as examples.

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Novel type of flow injection immunoassay for the determination of phenytoin in serum

Cited by 14 publications

References 27 publications

Analysis of Free Drug Fractions Using Near-Infrared Fluorescent Labels and an Ultrafast Immunoextraction/Displacement Assay

Analysis of Free Drug Fractions Using Near-Infrared Fluorescent Labels and an Ultrafast Immunoextraction/Displacement Assay

Capillary Zone Electrophoresis Analysis of Anti-Epileptic Drugs

Labeling strategies for bioassays

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