Voltammetric determination of isoxsuprine and fenoterol in dosage forms and biological fluids through nitrosation.

A simple and highly sensitive voltammetric method was developed for the determination of isoxsuprine HCl (I) and fenoterol HBr (II) in dosage forms and biological fluids. The method is based on treatment of the two compounds with nitrous acid followed by measuring the cathodic current produced by the resulting nitroso derivatives. The voltammetric behavior was studied adopting Direct Current (DCt), Differential Pulse (DPP) and Alternating Current (ACt) polarography. Both compounds produced well-defined, diffusion-controlled cathodic waves over the whole pH range in Britton-Robinson buffers (BRb). At pH 11 and pH 9, the values of diffusion-current constants (Id), were 9.4 +/- 0.3 and 7.7 +/- 0.4 for I and II, respectively. The current-concentration plots for I were rectilinear over the range of 0.6-12 microg/ml and 0.1-12 microg/ml in the DCt and DPP modes, respectively. As for II, the range was 1-20 microg/ml and 0.1-20 microg/ml in the DCt and DPP modes, respectively. The minimum detectability (S/N = 2) were 0.02 microg/ml (approximately 6 x 10(-8) M) and 0.01 microg/ml (approximately 2.6 x 10(-8) M) for I and II, respectively, adopting the DPP mode. The proposed method was applied to the determination of both compounds in dosage forms and the results obtained were in good agreement with those obtained using reference methods. The proposed method was further applied to the determination of isoxsuprine in spiked human urine and plasma. The percentage recoveries adopting the DPP mode were 98.84 +/- 1.18 and 99.26 +/- 0.97, respectively.

[1]  P. Gallo,et al.  Alpha 1-acid glycoprotein affinity columns for the clean-up of adrenergic drugs. , 1998, The Analyst.

[2]  Martindale : the extra pharmacopoeia , 1996 .

[3]  L. Meites,et al.  The Calculation of Electrochemical Kinetic Parameters from Polarographic Current-Potential Curves , 1961 .

[4]  G. Jacobson,et al.  High-performance liquid chromatographic assay for the simultaneous determination of ipratropium bromide, fenoterol, salbutamol and terbutaline in nebulizer solution. , 1994, Journal of pharmaceutical and biomedical analysis.

[5]  M. Walash,et al.  Polarographic determination of prenalterol hydrochloride through treatment with nitrous acid. , 1995, Journal of pharmaceutical and biomedical analysis.

[6]  R. Colombo,et al.  Determination of isoxsuprine in human plasma by gas chromatography with electron capture detection. , 1983, Pharmacology.

[7]  J. van der Greef,et al.  On-capillary isotachophoresis for loadability enhancement in capillary zone electrophoresis/mass spectrometry of beta-agonists. , 1994, Biological mass spectrometry.

[8]  M. Walash,et al.  Polarographic determination of EDTA in certain pharmaceutical dosage forms. , 1998, Journal of pharmaceutical and biomedical analysis.

[9]  F. Belal,et al.  Polarographic determination of some penicillins through nitrosation. , 1998, Journal of pharmaceutical and biomedical analysis.

[10]  A. Polettini,et al.  Applicability of coupled-column liquid chromatography to the analysis of β-agonists in urine by direct sample injection I. Development of a single-residue reversed-phase liquid chromatography-UV method for clenbuterol and selection of chromatographic conditions suitable for multi-residue analysis , 1995 .

[11]  J. Greef,et al.  A novel sheathless and electrodeless microelectrospray interface for the on‐line coupling of capillary zone electrophoresis to mass spectrometry , 1997 .

[12]  D. Breimer.  Topics in Pharmaceutical Sciences , 1982 .

[13]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[14]  P. Stouten,et al.  Determination of fenoterol and ractopamine in urine by enzyme immunoassay. , 1994, The Analyst.

[15]  M. Smyth,et al.  Voltammetric study of salbutamol, fenoterol and metaproterenol at unmodified and Nafion-modified carbon paste electrodes , 1994 .

[16]  Albert,et al.  Food , 1917, Nature.

[17]  M. Reddy,et al.  SPECTROPHOTOMETRIC DETERMINATION OF ISOXSUPRINE AND NYLIDRIN USING 1,10-PHENANTHROLINE , 1998 .

[18]  J. Miller,et al.  Statistics for Analytical Chemistry , 1993 .

[19]  K. Rominger,et al.  Radioimmunological determination of fenoterol. Part II: Antiserum and tracer for the determination of fenoterol. , 1990, Arzneimittel-Forschung.

[20]  C. Elliott,et al.  Development of a dual label time-resolved fluoroimmunoassay for the detection of β-agonists in cattle urine , 1996 .

[21]  R. Brereton,et al.  Multivariate calibration on designed mixtures of four pharmaceuticals , 1998 .

[22]  H. Matthys,et al.  New method for easy labeling of beta-2-agonists in the metered dose inhaler with technetium 99m. , 1988, Respiration; international review of thoracic diseases.