Simultaneous determination of trace amounts of anti-hypertensive drugs in urine using magnetic mixed hemimicelles solid-phase extraction combined with HPLC-UV

Resumo

Hypertension is the leading cause of morbidity and mortality in developed and developing countries. The combination of amlodipine and carvedilol is very effective for reducing blood pressure and improving treatment compliance. Determination of drugs in biological fluids is vital in therapeutic efficacy. In the present study, a simple, rapid and efficient magnetic solid phase extraction procedure based on mixed hemimicelles is described and validated for the simultaneous determination of trace amounts of anti-hypertensive drugs in urine samples using sodium dodecyl sulfate-coated magnetite nanoparticles as extractant. Various factors, which could affect the extraction efficiency were investigated and optimized. Under the optimum conditions, the limits of detection (S/N = 3) for amlodipine and carvedilol were 5 and 2 ng/mL, respectively. The relative standard deviation for six measurements of 50 ng/mL of amlodipine and carvedilol were 4.7 and 5.2%, respectively. The developed method was applied to the analysis of patients' urine samples, and satisfactory results were obtained in the range between 81.6 and 92.7%.