title: Fully automated analytical procedure for propofol determination by sequential injection technique with spectrophotometric and fluorimetric detections.
abstract: In this work, an application of an enzymatic reaction for the determination of the highly hydrophobic drug propofol in emulsion dosage form is presented. Emulsions represent a complex and therefore challenging matrix for analysis. Ethanol was used for breakage of a lipid emulsion, which enabled optical detection. A fully automated method based on Sequential Injection Analysis was developed, allowing propofol determination without the requirement of tedious sample pre-treatment. The method was based on spectrophotometric detection after the enzymatic oxidation catalysed by horseradish peroxidase and subsequent coupling with 4-aminoantipyrine leading to a coloured product with an absorbance maximum at 485 nm. This procedure was compared with a simple fluorimetric method, which was based on the direct selective fluorescence emission of propofol in ethanol at 347 nm. Both methods provide comparable validation parameters with linear working ranges of 0.005-0.100 mg mL(-1) and 0.004-0.243 mg mL(-1) for the spectrophotometric and fluorimetric methods, respectively. The detection and quantitation limits achieved with the spectrophotometric method were 0.0016 and 0.0053 mg mL(-1), respectively. The fluorimetric method provided the detection limit of 0.0013 mg mL(-1) and limit of quantitation of 0.0043 mg mL(-1). The RSD did not exceed 5% and 2% (n=10), correspondingly. A sample throughput of approx. 14 h(-1) for the spectrophotometric and 68 h(-1) for the fluorimetric detection was achieved. Both methods proved to be suitable for the determination of propofol in pharmaceutical formulation with average recovery values of 98.1 and 98.5%.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
authors.forename: Ivana
authors.initials: I
authors.lastname: Šrámková
authors.forename: Célia G
authors.initials: CG
authors.lastname: Amorim
authors.forename: Hana
authors.initials: H
authors.lastname: Sklenářová
authors.forename: Maria C B M
authors.initials: MC
authors.lastname: Montenegro
authors.forename: Burkhard
authors.initials: B
authors.lastname: Horstkotte
authors.forename: Alberto N
authors.initials: AN
authors.lastname: Araújo
authors.forename: Petr
authors.initials: P
authors.lastname: Solich
mesh_terms: D000675:Ampyrone / Q000378:metabolism; D001331:Automation; D017022:Flow Injection Analysis / Q000379:methods*; D005453:Fluorescence; D005470:Fluorometry / Q000379:methods*; D006735:Horseradish Peroxidase / Q000378:metabolism; D007202:Indicators and Reagents / Q000378:metabolism; D015742:Propofol / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D007202:Indicators and Reagents; D000675:Ampyrone; D006735:Horseradish Peroxidase; D015742:Propofol
keywords: 4-Aminoantipyrine; Emulsions; Horseradish peroxidase; Propofol; Sequential Injection Analysis