title: Determination of methylprednisolone acetate in biological fluids at gold nanoparticles modified ITO electrode.
abstract: The electrochemical behavior of a corticosteroid methylprednisolone (MP), used for doping, has been studied at gold nanoparticles modified indium tin oxide (nanoAu/ITO) electrode. The nanoAu/ITO electrode exhibited an effective catalytic response towards its oxidation and lowered its oxidation potential by approximately 127 mV when compared with bare ITO electrode. Oxidation of MP has been carried out in phosphate containing electrolyte in the pH range 2.13-10.00 and a well-defined oxidation peak was noticed. Linear concentration curves are obtained over the concentration range 0.01-1.0 microM with a detection limit of 2.68 x 10(-7)M at nanoAu/ITO electrode. A diffusion coefficient of 2.36 x 10(-6)cm(2)/s is calculated for MP using chronoamperometry. The proposed method is effectively applied to detect the concentration of MP in pharmaceutical formulations and human blood plasma and urine samples. A comparison of MP concentration determined in blood plasma and urine by the proposed method and GC/MS indicated that the results are essentially similar. It is believed that the method will be useful in determining this drug in case of doping.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India. rngcyfcy@iitr.ernet.in
authors.forename: Rajendra N
authors.initials: RN
authors.lastname: Goyal
authors.forename: Munetaka
authors.initials: M
authors.lastname: Oyama
authors.forename: Akrajas A
authors.initials: AA
authors.lastname: Umar
authors.forename: Anuradha
authors.initials: A
authors.lastname: Tyagi
authors.forename: Neeta
authors.initials: N
authors.lastname: Bachheti
mesh_terms: D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D005938:Glucocorticoids / Q000097:blood* / Q000737:chemistry / Q000652:urine*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007204:Indium / Q000737:chemistry; D008775:Methylprednisolone / Q000097:blood* / Q000737:chemistry / Q000652:urine*; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D005938:Glucocorticoids; D010710:Phosphates; D017971:Tin Compounds; D007204:Indium; D006046:Gold; C045358:stannic oxide; D008775:Methylprednisolone