Stability of acetylsalicylic acid in human blood collected using volumetric absorptive microsampling (VAMS) under various drying conditions

Abstract

Acetylsalicylic acid (ASA) is one of the most commonly used medications in global market, with a risk of intoxication in certain patients. However, monitoring blood drug concentration often requires frequent hospital visits; hence there is an unmet need to increase patient-centricity by conducting blood sampling at home. Volumetric absorptive microsampling (VAMS) is a device that allows collection of homogenous and accurate volume of blood without venipuncture, and can be utilized by patients who are not in hospital settings; but because ASA is prone to hydrolysis and stabilizing reagents cannot be added to VAMS samples, a way to improve sample stability must be developed. The objective of this study was to identify the cause of instability with ASA samples collected by VAMS, and to evaluate ways to improve sample stability. A liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used for analysis of ASA concentration in whole blood. Samples collected with VAMS were kept under different drying conditions (desiccator, pressurized, nitrogen gas and household vacuum sealer) and were compared to the control samples collected by conventional venous sampling. The recovery of ASA was about 31% of the control when VAMS sample was dried at room temperature, whereas VAMS samples under humidity controlled conditions showed more than 85% of recovery. Our results suggest that adequate level of humidity control was critical to ensure sample stability of ASA, and this humidity control could also be achieved at home using household vacuum sealer, thus enabling patient-centric clinical trials to be conducted.

Blood microsampling technologies: Innovations and applications in 2022

“…showed that humidity control was critical for its stability, and the use of a simple household vacuum sealer could maintain the stability for up to 1 month. 33 Similar to DBS filter paper modifications, the polymeric tips can be modified to attain new features.…”

“…Nevertheless, different drying conditions, such as the use of a desiccator, pressurization, nitrogen gas and household vacuum sealer, have been shown to improve sample stability. In the analysis of acetylsalicylic acid, a hydrolysis‐prone analyte, Moon et al showed that humidity control was critical for its stability, and the use of a simple household vacuum sealer could maintain the stability for up to 1 month 33 …”

“…In the analysis of acetylsalicylic acid, a hydrolysis‐prone analyte, Moon et al showed that humidity control was critical for its stability, and the use of a simple household vacuum sealer could maintain the stability for up to 1 month. 33 …”

“… 20 Furthermore, paper‐based ionization techniques such as paper spray ionization (PSI) for MS have enabled the direct analysis of a broad spectrum of analytes in dried microsamples without the requirement of any prior sample pretreatment. 21 These sophisticated approaches have driven the implementation of microsampling in various biomedical domains; newborn and metabolic screening, 22 , 23 biomarker research, 21 , 24 , 25 pharmacokinetic (PK) and pharmacodynamic (PD) studies, 26 , 27 therapeutic drug monitoring (TDM), 28 , 29 , 30 , 31 , 32 , 33 forensic toxicology, 34 , 35 , 36 sports anti‐doping, 37 , 38 , 39 metabolomics 22 , 40 , 41 and proteomics. 24 , 42 , 43 Since 70% of medical decisions are governed by diagnostic blood tests, 44 several medical technology companies are investing in the development of innovative at‐home blood microsampling devices to make blood work more accessible and convenient.…”