Determination of Vancomycin Hydrochloride in Pharmaceutical Forms and Urine Samples Using Modified Magnetic Iron Oxide Nanoparticles

Magnetic solid-phase extraction is an efficient and low-cost spectrophotometric method that can be utilized for extraction and determination of pharmaceutical compounds. Vancomycin is an antibiotic used in the treatment of life-threatening infections caused by Gram-positive bacteria. This study utilized magnetic solid-phase extraction for the determination of vancomycin hydrochloride (VAN) in different matrices. The separation and determination performed on magnetic iron oxide nanoparticles (IONPs) was modified using cetyltrimethylammonium bromide (CTAB). An azo dye product results from the coupling of VAN with the diazotized 4-aminoacetophenone in alkaline medium. This product was extracted and measured spectrophotometrically at λmax of 456 nm. Factors affecting the efficiency of removing the dye, such as pH of the solution, volume of reagent, CTAB amount, adsorbent amount, extraction time and desorption conditions, were studied. Under optimal extraction conditions, the linearity concentrations range was 0.1–6 µg/mL. The limit of detection and the limit of quantification was calculated to be 0.075 and 0.25 µg/mL, respectively. The method was applied successfully for the fast analysis of VAN in its dosage forms using the CTAB-coated IONPs, and the extraction process could be completed within 10 min.