Factorial design-assisted spectroscopic determination of oxybutynin hydrochloride.

Eman Yosrey,Heba Elmansi,Mohamed El-Sayed Metwally,Zeinab A Sheribah

doi:10.1098/rsos.211027

Abstract

In this study, we have developed two facile spectroscopic methods for quantifying oxybutynin (OBT) hydrochloride in its pure form and tablets using design of experiments (DOEs). The spectroscopic methods depended on the ion-pair complex formation between the tertiary amino group in the drug and eosin in 0.2 M acetate buffer of pH 4. Method I involves spectrophotometric measurement of the absorbance of the developed complex at 550 nm and showed linearity through 1.0–10.0 µg ml−1. Method II involves spectrofluorometric measurement of the quenching influence of OBT on the native fluorescence of eosin (λ excitation/λ emission of 304/548 nm) and showed linearity through 1.0–6.0 µg ml−1. Critical parameters were identified through preliminary trials and optimized using the DOE. Additionally, the quenching mechanism was investigated and the pathway of the reaction was postulated. The fluorescence quenching constant and thermodynamic parameters were explored using the Stern–Volmer plot and Van't Hoff graph, respectively. Assessments conducted via analytical ecoscale revealed the ‘excellent-greenness’ of the methodology. The two methods have the potentials of being green and fast compared with other reported methods.

Highlights

Overactive bladder (OAB) is a chronic medical condition in which patients suffer from ‘urinary urgency, with nocturnal enuresis, with or without urgency incontinence, where there is no urinary tract infection or other obvious pathology’ [1].Oxybutynin (OBT) hydrochloride 4-(diethylamino) but2-ynyl (RS)-2-cyclohexyl-2-hydroxy-2-phenylacetate hydrochloride [2] as an anticholinergic medication is recommended for patients with OAB or detrusor overactivity symptoms, including urinary frequency and urgency [3]
The developed spectroscopic methods using eosin Y (EY) attained these characteristics in addition to selectivity
EY is a carboxylic dye that is used as an ion-pairing reagent for the spectroscopic determination of cationic drugs in an acidic medium by forming ion-pair complexes [11,12,13,14,15]

Summary

Introduction

Overactive bladder (OAB) is a chronic medical condition in which patients suffer from ‘urinary urgency, with nocturnal enuresis, with or without urgency incontinence, where there is no urinary tract infection or other obvious pathology’ [1].Oxybutynin (OBT) hydrochloride (figure 1a) 4-(diethylamino) but2-ynyl (RS)-2-cyclohexyl-2-hydroxy-2-phenylacetate hydrochloride [2] as an anticholinergic medication is recommended for patients with OAB or detrusor overactivity symptoms, including urinary frequency and urgency [3]. Other reported methods include spectrofluorometry, spectrophotometry [4,5,6], voltammetry [7] and chromatography [8,9]. These methods are either timeconsuming, tedious or use expensive organic solvents harmful to the environment. The methods relied on the formation of an ion-pair complex between eosin Y (EY) and OBT. The interest in DOE originates from its ability to conclude the most effective factors, put them in order and study the interaction between these factors, which cannot be studied in one factor at a time This information is given through optimization plots and other charts, which improve the experimental parameters and method validation [16]. The greenness of the proposed methods was assessed by analytical ecoscale and showed higher score than the BP reference method [2]

Methods

Results

Conclusion