Infrared study of the acidic and basic forms of betaxolol

Canotilho, João; Castro, Ricardo A. E.; Helena, Maria; Teixeira, S.F.; Leitão, M. Luísa P.; Redinha, J.S.

doi:10.1016/j.saa.2005.07.021

Cited by 11 publications

(2 citation statements)

References 15 publications

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“…The stretch frequency observed for the OH free group is slightly above the values tabled [11,12] for this group (3650-3600 cm −1 ). Overestimated frequencies are commonly observed in this spectral region, using the conventional scale factor referred above [13,14].…”

Section: Calculated Infrared Spectramentioning

confidence: 99%

Infrared spectroscopy of racemic and enantiomeric forms of atenolol

Castro

Canotilho

Barbosa

et al. 2007

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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The molecular structure of conformational isomorphs given by X-ray diffraction for racemic and enantiomeric atenolol were optimized at the HF/6-31G* level of theory and the infrared spectra of the structure were calculated. These spectra are used to characterize the differences between the various atenolol conformers.The spectra of the (R,S)-and S-atenolol solid forms were recorded and the bands corresponding to the functional groups identified with the aid of the calculated spectra, fitting analysis, temperature effect and H/D isotopic exchange. Particular attention was paid to the stretch vibration modes of the functional groups present in the atenolol.

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Section: Calculated Infrared Spectramentioning

confidence: 99%

Infrared spectroscopy of racemic and enantiomeric forms of atenolol

Castro

Canotilho

Barbosa

et al. 2007

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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“…Hence, rapid screening for multiple b-blockers in a single analysis has been of growing demand in clinical toxicology and forensic science, 11 and antidoping control as well. 12 Betaxolol (BET), DL-[4-{2-cyclo-propylmethoxyethyl}-1-phenoxy-3-isopropylamino-2-propanol] (Scheme 1(a)), is a cardioselective b-adrenergic blocking agent characterized by a high bioavailability (90%) and a long half-life in man of about 16-22 h. 13 BET is an approved clinically used bblocker, 14 which produces vasodilatation and is effective for the treatment of arterial hypertension, intraocular hypertension, 15 coronary artery disease and chronic cardiovascular diseases. 16 Various analytical methods, such as gas chromatography-mass spectrometry (GC-MS) after derivatization, 17 liquid chromatography-mass spectrometry (LC-MS), 18 gas chromatographymass spectrometry in selected ion monitoring mode, 19 ultra-performance liquid chromatography-UV detection (UPLC-UV) 20 and UPLC-MS 21 have been applied for determination of different b-blockers.…”

Section: Introductionmentioning

confidence: 99%

Central composite rotatable design in the development of a new method for optimization, voltammetric determination and electrochemical behavior of betaxolol in the presence of acetaminophen based on a gold nanoparticle modified electrode

2012

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In the present study, the oxidation peak current of the betaxolol in a 0.20 M Britton-Robinson buffer solution was optimized by experimental design for its determination in the presence of acetaminophen. A central composite rotatable design was used to evaluate the effects of the variables by the differential pulse voltammetry method. These variables include scan rate, step potential, modulation amplitude, gold nanoparticles content and pH. Then, under the optimized conditions the dynamic range for betaxolol in the presence of acetaminophen was from 0.50 mM to 125.00 mM and the detection limit was found to be 46.00 nM. The characterization of the gold nanoparticle modified carbon paste electrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Other voltammetric methods such as double-potential step chronoamperometry and linear sweep voltammetry were also applied. Using these methods, the diffusion coefficient (D ¼ 7.43 Â 10 À5 cm 2 s À1 ) and the kinetic parameters such as the electron transfer coefficient (a ¼ 0.60) and exchanging current density (j 0 ¼ 4.6 Â 10 À4 mA cm À2 ) for BET were determined. The results indicated that the gold nanoparticle modified carbon paste electrode could be employed for the determination of betaxolol in real samples such as pharmaceutical formulations and plasma samples.

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