An eco-friendly one-pot spectrofluorimetric approach for the facile determination of overactive bladder drug, tolterodine: Application to dosage forms and biological fluids

Tolterodine tartrate (TTD) was the first antimuscarinic medication developed exclusively for the treatment of overactive bladder syndrome and was approved by the FDA in 1998. As a result of the drug's extensive utilization within the local community following its authorization, there is a pressing need to develop and validate a spectrofluorometric method that is economically efficient, easily reproducible, environmentally sustainable, and possesses high sensitivity. The developed approach relies on enhancing the fluorescence intensity of TTD to reach a level 720 % higher than its initial value, achieved through the application of an aqueous sodium dodecyl sulfate (SDS) solution. A strong correlation was observed with a correlation coefficient of 0.9998 between the concentration of TTD and the fluorescence intensity within the range of 25.0-500.0 ng mL-1. This approach could be employed to quantify TTD in its pure form and to examine pharmaceutical tablets for the purposes of verifying uniform content. Additionally, it was utilized for the evaluation of TTD concentrations in spiked human plasma.

Voltammetric Analysis of Ephedrine in Pharmaceutical Dosage Forms and Urine Using poly(Nile Blue A) Modified Glassy Carbon Electrode

OBJECTIVE

The electrochemical analysis of ephedrine which is a sympathometric drug has been studied using poly(Nile blue A) modified glassy carbon electrodes, cyclic voltammetry, differential pulse voltammetry and square wave voltammetry.

METHODS

The modified electrodes were prepared by potential cycling electropolymerization of Nile blue A in 0.1 M phosphate buffer solution at pH 6.0. The redox behavior of ephedrine was investigated in different buffer solutions at pH values between 5.5 and 9.0.

RESULTS

Scan rate studies showed that the electron transfer reaction of ephedrine was diffusion controlled. A linear response was obtained between the peak current and the ephedrine concentration in the range of 0.6 to 100 μM with a limit of detection of 2.91×10^-3 μM for differential pulse voltammetry in Britton-Robinson buffer solution at pH 9.0. The linearity range of ephedrine in human urine was between 1.0 and 100 μM with a detection limit of 8.16 nM.

CONCLUSION

The recovery studies in both pharmaceutical dosage forms and urine showed that the proposed method ensured good selectivity, precision and accuracy without any interference from inactive excipients.

Fourier convolution versus derivative spectrophotometry: Application to the analysis of two binary mixtures containing tamsulosin hydrochloride as a minor component

Simple and rapid spectrophotometric methods are described for determination of two mixtures of tamsulosin (TM), as minor component, with either solifenacin (SL) or tolterodine (TL). The proposed methods involve treatment of the absorbance ratio spectra or zero order spectra by derivative or discrete Fourier function. TM and TL mixture could not be resolved by manipulation of their zero order spectra due to the strong overlap between both spectra and only derivative or Fourier function coefficients of ratio spectra could resolve their spectra. TM and SL mixture was fully resolved by the manipulation of both ratio and zero order spectra. The values of the derivative or the Fourier function coefficients of ratio spectra and/or zero order spectra, at either peak or trough points, were correlated to the concentration of each drug in each mixture. Calibration graphs were linear in ranges 2.5-40 and 30-500μg.mL^-1 using derivative ratio and Fourier function ratio, 5-40 and 80-600μg.mL^-1 using direct derivative and 2.5-40 and 30-300μg.mL^-1 using direct Fourier function for TM and SL, respectively. The plots of derivative ratio amplitude and the Fourier function ratio coefficient versus concentration were linear over ranges 2.5-20 and 25-250μg.mL^-1 for TM and TL, respectively. Higher sensitivity as indicated by lower values of detection and quantitation limits were obtained using Fourier convoluted spectra (ratio or zero order) compared to derivative methods. All validation aspects per ICH guidelines are included. The proposed methods were also applied for the studied drugs assay in their tablets and capsules.

Tolterodine Tartrate

Tolterodine tartrate belongs to the family of muscarinic receptor antagonists and is indicated for the treatment of overactive urinary bladder syndrome. This chapter provides an overview of physical, analytical, and ADME profiles; highlights methods of chemical synthesis; and discusses stability of tolterodine as a free base and/or its l-tartrate salt in solution and in the solid state. The information presented in this chapter is based on the peer-reviewed literature, compendial reports (USP, EP), and authors' data. Patent literature is included only in a few instances.