A New Ritodrine Selective Electrode and its Pharmaceutical Application

Reda Ammar

doi:10.1155/2010/102162

Abstract

A novel ritodrine hydrochloride ion-selective PVC membrane electrode based on ion-pair complex of ritodrine-tetra phenyl borate was prepared withdi-n-butyl phosphate as a plasticizer. The influences of membrane composition, temperature, pH of the test solution and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian response over a wide ritodrine concentration range (1×10−5- 1×10−2M) with a slope of 59.33 mV decade−1and was found to be very selective, precise and usable within the pH range 3-7.5. The standard electrode potentials, E°, were determined at different temperatures and used to calculate the isothermal temperature coefficient (dE°/dT) of the electrode, which was 0.00075. The electrode was successfully used for potentiometric determination of ritodrine hydrochloride both in pure solutions and in pharmaceutical preparations.

Highlights

Ritodrine hydrochloride (RTH), chemically [1-(4- hydroxy phenyl)-2-[2-(4-hydroxy phenyl) ethyl amino] propanol-hydrochloride], is a selective β2- adrenergic agonist solely used as uterine relaxant
The aim of the present work, describes a sensitive and reasonably selective poly membrane electrode based on the use of ritodrine - tetra phenyl borate as a novel electroactive material
The same method was applied for the determination of RTH in the pharmaceutical preparations

Summary

Introduction

Ritodrine hydrochloride (RTH), chemically [1-(4- hydroxy phenyl)-2-[2-(4-hydroxy phenyl) ethyl amino] propanol-hydrochloride], is a selective β2- adrenergic agonist solely used as uterine relaxant. Stock ritodrine hydrochloride solution (1×10−1 M) was prepared daily by dissolving an appropriate amount of the drug in double distilled water. The resulting precipitate was filtered, washed thoroughly with double distilled water till chloride free (tested using AgNO3 solution) and dried at room temperature for at least 3 days. Suitable increments of standard drug solution were add to 50 mL doubly distilled water so as to cover the concentration range from 1×10−6 - 1×10−2 M. In this solution the sensor and reference electrode were immersed and the e.m.f values were recorded after each addition. The electrode was washed with double distilled water and dried between measurements

A New Ritodrine Selective Electrode

Results and Discussion

10-5 M 10-4 M 10-3 M 100

Conclusion