Validated electroanalytical determination of flavoxate hydrochloride and tolterodine tartrate drugs in bulk, dosage forms and urine using modified carbon paste electrodes

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.

Simultaneous ultra-sensitive analysis of tamsulosin hydrochloride and tolterodine tartrate binary mixture in their dosage form via high-performance thin-layer chromatography with fluorimetric detection

A simple, sensitive, selective, and stability-indicating high-performance thin-layer chromatography method with fluorescence detection was developed for the analysis of a mixture of tamsulosin hydrochloride and tolterodine tartrate, used in the management of benign prostatic hyperplasia in their laboratory-prepared binary mixture and dosage form. The separation was employed on thin-layer chromatography silica gel 60 aluminum sheets. As developing system, ethyl acetate–n-hexane–diethylamine (9:3:1, V/V) was used. Tamsulosin and tolterodine had retention factors (RF) of 0.40 ± 0.03 and 0.85 ± 0.03, respectively. A 225 nm excitation wavelength was used for the fluorescence detection. Linearity was in the range of 10.0–200.0 and 100.0–900.0 ng/band for tamsulosin and tolterodine, respectively. The method was validated successfully according to the International Council for Harmonisation guidelines. Our suggested method for determining tamsulosin and tolterodine in their dosage forms and in the presence of their degradation products could be conveniently applied in quality-control laboratories.

RP-HPLC Method for the Simultaneous Determination of a Quaternary Mixture of Propyphenazone, Flavoxate HCl and Two of Their Official Impurities with Dissolution Profiling of Their Tablets

BACKGROUND

Determination of different drugs in the presence of their impurities is now receiving attention from regulatory authorities such as the ICH and the United States Food and Drug Administration (USFDA).

OBJECTIVE

To develop and validate a reversed-phase (RP)-HPLC method for the simultaneous separation and quantification of a quaternary mixture of propyphenazone, flavoxate HCl, and their official impurities; phenazone and 3-methylflavone-8-carboxylic acid, respectively. Then utilize the validated method as an in vitro methodology to monitor the rate of release of the active ingredients from Cistalgan® tablets.

METHODS

RP-HPLC method was applied using Kinetex® coreshell C8 column (250 mm × 4.6 mm I.D., particle size 5 μm) and acetonitrile: phosphate buffer pH 3.50 (42:58, v/v) as the mobile phase with UV detection at 240.0 nm.

RESULTS

The studied components were eluted with average retention times of 2.80, 3.40, 4.20, and 5.90 min for phenazone, flavoxate HCl, 3-methylflavone-8-carboxylic acid, and propyphenazone, respectively within linearity range of 1.00-60.00 µg/mL propyphenazone, 3.00-60.00 µg/mL flavoxate HCl and 0.50-40.00 µg/mL of the specified impurities.

CONCLUSIONS

The suggested method could be considered as the first validated analytical method for the simultaneous determination of the studied components and proved to be accurate, precise, sensitive, and robust.

HIGHLIGHTS

The proposed method displays a useful analytical tool for dissolution profiling and clear discrimination of both active ingredients from their impurities along with impurities profiling.

A Comprehensive Review on Developed Pharmaceutical Analysis Methods by Iranian Analysts in 2018

This article summarizes the publishing activities including bioanalytical and pharmaceutical analyses researches carried out in Iran in 2018 in order to connect academic researchers to those in industry, medical care units and hospitals. A wide spectrum of analytical methods has been used to determine and/or evaluate drug levels in the biological samples, based on physical, chemical and biochemical principles. We have compiled a concise survey of the literature covering 125 reports and tabulated the relevant analytical parameters. Chromatographic and electrochemical methods were found to be the technique of choice for many workers and almost 83% studies were performed by using these methods. This is the first annual review of the literature searching in SCOPUS database for published bioanalytical and pharmaceutical analysis researches in Iran.

Simultaneous Determination of Moxifloxacin and Flavoxate by RP-HPLC and Ecofriendly Derivative Spectrophotometry Methods in Formulations

Simple, fast, and precise reversed-phase (RP)-high-performance liquid chromatography (HPLC) and two ecofriendly spectrophotometric methods were established and validated for the simultaneous determination of moxifloxacin HCl (MOX) and flavoxate HCl (FLX) in formulations. Chromatographic methods involve the separation of two analytes using an Agilent Zorbax SB C18 HPLC column (150 mm × 4.6 mm; 5 µm) and a mobile phase consisting of phosphate buffer (50 mM; pH 5): methanol: acetonitrile in a proportion of 50:20:30 v/v, respectively. Valsartan was used as an internal standard. Analytes were monitored by measuring the absorbance of elute at 299 nm for MOX and 250 nm for FLX and valsartan. Two environmentally friendly spectrophotometric (first derivative and ratio first derivative) methods were also developed using water as a solvent. For the derivative spectrophotometric determination of MOX and FLX, a zero-crossing technique was adopted. The wavelengths selected for MOX and FLX were −304.0 nm and −331.8 nm for the first derivative spectrophotometric method and 358.4 nm and −334.1 nm for the ratio first-derivative spectrophotometric method, respectively. All methods were successfully validated, as per the International Conference on Harmonization(ICH) guidelines, and all parameters were well within acceptable ranges. The proposed analytical methods were successfully utilized for the simultaneous estimation of MOX and FLX in formulations.