The degradation of salbutamol in ethanolic solutions

Cope, Mike; Bautista-Parra, Fernando

doi:10.1016/j.jpba.2010.01.003

Cited by 5 publications

(6 citation statements)

References 12 publications

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“…It is also used to reduce premature labor in pregnancy [6]. Salbutamol is commonly administrated as pressurized metered dose inhaler and nebulized aerosol [7]. Salbutamol has been pharmacologically proven to be able to increase muscle protein, reduce total body fat, and promote muscle growth, therefore, it is highly abused by athletes to improve muscular strength and in turn improve their performance in sports [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Single-Walled-Carbon-Nanotube-Modified Pyrolytic Graphite Electrode Used as a Simple Sensor for the Determination of Salbutamol in Urine

Goyal

Bishnoi

Agrawal

2011

International Journal of Electrochemistry

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A fast and sensitive voltammetric method has been proposed for the determination of salbutamol at single-walled-carbon-nanotube-modified edge-plane pyrolytic graphite electrode (SWNT/EPPGE) in human urine. The electrochemical response of salbutamol was determined by square wave voltammetry (SWV) in phosphate buffer solution (PBS) at physiological pH 7.2. The modified electrode showed improved voltammetric response towards the oxidation of salbutamol, and a well-defined anodic peak was observed at~600 mV with enhanced peak current in comparison to the bare electrode. Linear calibration plot using SWNT/EPPGE was obtained in the concentration range of 50 to 2500 ngml-1with sensitivity and detection limit of 2.15 nA/ngml-1and 4.31 ngml-1, respectively. The developed method has been successfully applied for the determination of salbutamol in commercial preparations and human body fluids. Fast analysis of salbutamol in human urine makes the proposed method of great interest for doping control purposes at the site of competitive games.

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Section: Introductionmentioning

confidence: 99%

Single-Walled-Carbon-Nanotube-Modified Pyrolytic Graphite Electrode Used as a Simple Sensor for the Determination of Salbutamol in Urine

Goyal

Bishnoi

Agrawal

2011

International Journal of Electrochemistry

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“…The mechanism for the formation of the degradation products has been proposed for ethanolic solutions (Cope and Bautista‐Parra, ), but it is probably the same for methanolic solutions. The reaction starts by the protonation of an alcoholic hydroxyl, generating a good leaving group which is then substituted in an S N 2 mechanism directly by methanol followed by deprotonation, yielding the final product.…”

Section: Resultsmentioning

confidence: 98%

“…Ethanolic salbutamol solutions are known to be unstable and lead to the formation of ether degradation products (Cope and Bautista‐Parra, ). According to this work, however, ethanolic solutions take up to 9 months at 25°C to show considerable degradation.…”

Section: Resultsmentioning

confidence: 99%

“…This study, however, did not evaluate the influence of sample pH in a possible degradation (Bergés et al, 2000). Ion m/z 86 was used for detection and quantification of salbutamol and its degradation products, since this ion arises from the cleavage of the chemical bond located β to the nitrogen atom, which was expected to be unaltered, based on previous studies (Cope and Bautista-Parra, 2010). There is a pH influence on the formation of the degradation products in urine as one of the detected degradation products is preferentially formed in alkaline medium, while the other two are favored in acid pH values.…”

Section: Resultsmentioning

confidence: 99%

“…Salbutamol, however, is unstable in some solutions, as previously reported (Bergés et al ., ; Cope and Bautista‐Parra, ; Forsdahl and Gmeiner, ; Henze, ), and this instability is critical in all kinds of analysis, because salbutamol quantifications might be strongly affected by degradation. An additional issue is that many laboratories monitor β ‐agonists using a screening procedure that was originally developed for anabolic steroids, which gives extraction yields of about 8% only based on our laboratory validation experiments.…”

Section: Introductionmentioning

confidence: 99%

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Salbutamol extraction from urine and its stability in different solutions: identification of methylation products and validation of a quantitative analytical method

Garrido

Silva

Borges

et al. 2013

Biomedical Chromatography

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Salbutamol is commonly used in asthma treatment, being considered a short-effect bronchodilator. This drug poses special interest in certain fields of chemical analysis, such as food, clinical and doping analyses, in which it needs to be analyzed with quantitative precision and accuracy. Salbutamol, however, is known to degrade under certain conditions and this is critical if quantitative results must be generated. The present work aimed to investigate salbutamol extraction from urine samples, to determine whether salbutamol is unstable in other solvents as well as in urine samples, to elucidate the structures of the possible degradation products and to validate an analytical method using the extraction procedure evaluated. Stability investigations were performed in urine at different pH values, in methanol and acetone at different temperatures. Semi-preparative liquid chromatography was performed for the isolation of degradation products, and gas chromatography coupled to mass spectrometry as well as nuclear magnetic resonance were used for identification. Three unreported methylation products were detected in methanolic solutions and had their structures elucidated. Urine samples showed a reduction in salbutamol concentration of up to 25.8% after 5 weeks. These results show that special care must be taken regarding salbutamol quantitative analyses, since degradation either in standard solutions or in urine could lead to incorrect values.

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