Determination of Albuterol Enantiomers in Animal Tissue Matrices by LC–MS/MS: Application in Therapeutic Myoanabolic Studies

Abstract

Albuterol (salbutamol) is a widely used medication in respiratory disease including asthma and chronic obstructive airways disease; however, like other beta2-agonists, it also exerts some extrapulmonary effects on muscle and fat. Surprisingly, there have been relatively few reports of albuterol tissue distribution, and the distribution of individual albuterol enantiomers into tissue has not been reported. The method presented here explores the use of an HPLC tandem mass spectrometry (LC-MS/MS) system (LTQ Orbitrap hybrid mass spectrometer) with deuterated standard and solid-phase extraction to determine low levels of albuterol enantiomers in tissue. The lower limit of quantification (LLOQ) was 0.156 ng g -1 , with a precision RSD \15% for both enantiomers. The assay was linear over the calibration range of LLOQ-10.0 ng g -1 in muscle tissue (r 2 [ 0.98). The assay was successfully applied to pharmacokinetic studies in rats and mice. By utilizing a deuterated internal standard and LC-MS/MS detection, this assay can be used to measure albuterol enantiomers in muscle tissue. This assay has also identified that albuterol uptake appears to be stereoselective, and enantioselective assays are clearly warranted for myoanabolic studies involving administration of racemic-albuterol.

Enantioselective disposition of (R/S)‐albuterol in skeletal and cardiac muscle

“…Albuterol enantiomer analysis was performed using our previously reported method; assay performance data was within acceptable limits (lower limit of quantification (LLOQ) of 0.156 ng/g, a precision RSD <15% for both enantiomers and with the assay linear over the calibration range of LLOQ‐10.0 ng/g) …”

“…The samples were then placed in an ultrasonic bath for 15 min, centrifuged at 15 000 rpm for 15 mins, before the supernatant was extracted and diluted appropriately with distilled water and mixed 1:1 with pH10 ammonia buffer. The albuterol was extracted with SPE using Water Oasis TM HLB SPE cartridge and analyzed by liquid chromatography‐mass spectrometry (LC‐MS) assay in our laboratory as previously described …”

“…Albuterol enantiomer analysis was performed using our previously reported method; assay performance data was within acceptable limits (lower limit of quantification (LLOQ) of 0.156 ng/g, a precision RSD <15% for both enantiomers and with the assay linear over the calibration range of LLOQ-10.0 ng/g). [24] Due to the high dose given (MTD of 10 mg/kg), plasma samples were diluted 100-fold with distilled water prior to solidphase extraction (SPE) using Water Oasis TM HLB SPE cartridges. Tissue samples were extracted using SPE in a similar manner.…”

“…The albuterol was extracted with SPE using Water Oasis TM HLB SPE cartridge and analyzed by liquid chromatography-mass spectrometry (LC-MS) assay in our laboratory as previously described. [24]…”

Screening, recognition and quantitation of salbutamol residues in ham sausages by molecularly imprinted solid phase extraction coupled with high-performance liquid chromatography–ultraviolet detection

“…In order to analysis of SAL in biological samples, several methods have been developed, such as high performance liquid chromatography (HPLC) [1,7,8], capillary electrophoresis (CE) [9][10][11], gas chromatography-mass spectrometry (GC-MS) [12], liquid chromatography-mass spectrometry (LC-MS) [13,14], enzyme immunoassay [15], and bromatometric methods [16]. However, they are suffered to achieve separation of target compounds from complex sample matrices directly without the pretreatment process.…”