A Molecular Imprinted Polymer as a Flow-Through Optical Sensor for Oxazepam

Abstract

A flow-through optosensing system for oxazepam recognition with fluorescence detection was performed by means of a molecular imprinted polymer based on its acid hydrolysis product, 2-amino-5-chlorobenzophenone. The synthesis was conducted via a noncovalent imprinting methodology, using methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent. Hydrolysis (types and concentration of acids), polymer retention capacity, binding properties, and elution (selectivity and reversibility) conditions were optimized. The selected molecular imprinted polymer had a molar ratio composition of 1 : 6 : 45 (template : functional monomer : cross-linker). The proposed method was applied to the determination of oxazepam in a pharmaceutical formulation. External standard calibration, standard additions calibration, and Youden's calibration were carried out in order to evaluate constant and proportional errors due to the matrix. The developed metabolite-based recognition system for benzodiazepines is an innovative procedure that could be followed in routine and quality control assays.

Benzodiazepines in complex biological matrices: Recent updates on pretreatment and detection methods

“…Machicote et al. [ 192 ] developed a fluorescence recognition system for flow light sensing by synthesized MIPs using hydrolysates of oxazepam as template molecules in a non-covalent blotting method for the indirect detection of oxazepam from drug preparations. LOD and LOQ of 11.2 and 34.2 μg/mL, respectively, were obtained.…”

A Molecularly Imprinted Polymer as the Adsorbent for the Selective Determination of Oxazepam in Urine and Plasma Samples by High-Performance Liquid Chromatography with Diode Array Detection

“…The indirect determination of oxazepam in pharmaceutical formulations based on the development of an optical sensor for its acid hydrolysis product, 2-amino-5-chlorobenzophenone, was reported in 2018. A flow-through optosensing system for oxazepam recognition with fluorescence detection was performed by means of a molecularly imprinted polymer based on its acid hydrolysis product, 2-amino-5-chlorobenzophenone [22]. To the best of our knowledge, no report has yet demonstrated the development of MIPs which possessed both high binding capacity and selectivity for oxazepam in human urine and plasma samples.…”

Synthesis and characterization of molecularly imprinted polymers for the selective extraction of oxazepam from complex environmental and biological samples

“…However, it has been shown that the analysis of drugs at trace levels in environmental water samples or biological samples requires the selection of a dummy template to avoid false positives and/or overestimation of drug quantities due to the risk of template leakage when applying the MIP to real samples [29,30]. The use of a structural analogue as template was only described for the development of a MIP-based sensors to determine OXA in pharmaceutical formulation [31]. The present work aimed to evaluate the potential of MIP to selectively extract OXA which is one of the most marketed BZDs in France and an active metabolite of other BZDs.…”