Analysis of phenylbutazone in plasma by high-speed liquid chromatography

Pound, N. J.; McGilveray, I.J.; Sears, R.W.

doi:10.1016/s0021-9673(01)84155-8

Cited by 31 publications

(3 citation statements)

References 7 publications

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“…Taylor el al. (1981) reported a method modified from Pound's work (Pound et al, 1974) which employed a normal-phase column with a U V detector absorbance set at 240 nm. By increasing solvent polarity with tetrahydrofuran in the mobile phase and the flow rate to 100 ml/h, they were also to detect phenylbutazone, oxyphenbutazone and y-hydroxyphenylbutazone simultaneously, with percentage recoveries of 100,90, and 60, and limits of detection of 0.01, 0.05 pg/ml, and 0.1 pg/ml, respectively.…”

Section: Analytical Methodologymentioning

confidence: 99%

Phenylbutazone in the horse: a review

Tobin

Chay

Kamerling

et al. 1986

Vet Pharm & Therapeutics

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Phenylbutazone is an acidic, lipophilic, non-steroidal anti-inflammatory drug (NSAID). It is extensively metabolized in the horse. The metabolites so far identified, oxyphenbutazone, gamma-hydroxyoxyphenbutazone, account for some 25-30% of administered dose over 24 h. The plasma half-life of phenylbutazone and termination of its pharmacological action are determined primarily by its rate of hepatic metabolism. Phenylbutazone acts by inhibiting the cyclooxygenase enzyme system, which is responsible for synthesis of prostanoids such as PGE2. It appears to act on prostaglandin-H synthase and prostacyclin synthase, after conversion by prostaglandin-H synthase to reactive intermediates. It markedly reduces prostanoid-dependent swelling, edema, erythema, and hypersensitivity to pain in inflamed tissues. Its principal use in the horse is for treatment of soft tissue inflammation. Phenylbutazone is highly bound (greater than 98%) to plasma protein. After i.v. injection, blood levels decline with an elimination half-life of 3-10 h. The plasma kinetics of phenylbutazone may be dose dependent, with the plasma half-life increasing as the drug dosage level increases. Plasma residues of the drug at 24 h after a single i.v. dose of 2 g/450 kg average about 0.9 microgram/ml, but considerable variation occurs. If dosing is repeated, the plasma residue accumulates to give mean residual blood levels of approximately 4.5 microgram/ml on Day 5 after 4 days of dosing. Approximately similar blood levels are found after a combination of oral and i.v. dosing. Experiments on large numbers of horses in training have been undertaken to ascertain the population distributions of residual blood levels after such dosing schedules. Absorption of phenylbutazone from the gastrointestinal tract is influenced by the dose administered and the relationship of dosing to feeding. Access to hay can delay the time of peak plasma concentration to 18 h or longer. Under optimal conditions, the bioavailability of oral phenylbutazone is probably in the region of 70%. Paste preparations may be more slowly absorbed than other preparations and yield higher residual plasma levels at 24 h after dosing, but further controlled studies are required. Phenylbutazone is easily detected in the plasma and urine of horses but concentrations in saliva are low. It is quantitated for forensic purposes by HPLC. The variability of this method between laboratories is about +/- 25%. Increasing urinary pH increases the urinary concentration of phenylbutazone and its metabolites up to 200-fold.(ABSTRACT TRUNCATED AT 400 WORDS)

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Section: Analytical Methodologymentioning

confidence: 99%

Phenylbutazone in the horse: a review

Tobin

Chay

Kamerling

et al. 1986

Vet Pharm & Therapeutics

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“…The most common side effects of PBZ involves the gastrointestinal system. For the determination of PBZ, several analytical methods were reported, including high-performance liquid chromatography, [14][15][16][17] Direct injection HPLC method, 18,19 Proton magnetic resonance spectroscopic, 20,21 and gas chromatography-mass spectrometry. [22][23][24] However, the main issues with using such approaches, are the building up of detectors, time-consuming extraction, usage of costly instruments and separation practices.…”

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Electrochemical Sensing of Phenylbutazone using Multi-Walled Carbon Nanotube Paste Electrode in Pharmaceutical and Biological Fluids

Patil,

Megalamani,

Abbar

et al. 2024

ECS Adv.

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The electrochemical performance of phenylbutazone (PBZ) was studied using a multi-walled carbon-nanotube-modified paste electrode (MWCNT/CPE) using a variety of voltammetric tools like cyclic voltammetry (CV), linear sweep voltammetry (LSV), and square wave voltammetry (SWV). The results showed that the MWCNT/CPE exhibited remarkable electro-catalytic action towards the electrochemical oxidation of PBZ in a phosphate buffer solution of physiological pH 7 compared to a bare carbon paste electrode. The electro-kinetic parameters like heterogeneous rate constant, transfer coefficient, scan rate, pH, and involvement of electrons in electro-oxidation of PBZ was investigated. For bare CPE, the peak current was noted to be 19.53 µA with peak potential of 0.6871 V. For MWCNT/CPE, the peak current was 30.53 µA with peak potential of 0.6792 V. The anodic peak was analyzed, and the process was diffusion controlled. For the estimation of PBZ, a SWV technique was developed with great precision and accuracy, with a detection limit of 5.2 nM and a limit of quantification of 17nM, in the concentration range 1 x 10-7 to 10 x 10-6 M. The MWCNT/CPE has been used successfully for PBZ detection in injection, blood, and urine samples, with recovery rates of 98.9% to 101.5%, 96.3% to101.7% and 98.3% to 102.8%, respectively

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“…GLC (6)(7)(8)(9) and high-speed liquid chromatography (10,11) have been used to determine plasma levels of phenylbutazone, oxyphenbutazone, and the y-hydroxy derivative of phenylbutazone, but methods for I have not been reported. A GLC procedure for the quantitative determination of plasma I concentrations is reported here; it is suitable for pharmacokinetic studies.…”

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confidence: 99%