Comparative Study for determination of Metoclopramide Hydrochloride Drug by Selective Electrodes and Spectrophotometric methods.

Abstract

This study includes the determination of Metoclopramide Hydrochloride (METO) drug by Selective Electrodes and spectrophotometric methods.Selective Electrodes Method:These methods include construction of selective electrodes membrane based on complexation of drug with Phosphomolybdic acid (PM) as an active material and using Tributylphosphate (TBP) or Nitro benzene (NB)as a plasticizers , polyvinylchloride (PVC) was used as a matrix for these electrodes .The characters of each electrode were as follow :1.For electrode METO-PM using TBP as a plasticizer, the results were : 10-5 – 10-1, 18.2 mV/decade ,0.9938 , 1.97 x 10-7 M, and 2.5 – 3 at 25-30oC for linear range, slope , correlation coefficient , limit of detection, and optimum pH range and temperature respectively using internal filling solution of 10-3 M. The life time of the electrode was 26 days .2.For electrode METO-PM using NB as a plasticizer, the results were : 10-5 – 10-1, 18.9 mV/decade ,0.9975 , 1.83 x 10-7 M, and 2.7 – 3.2 at 25-30oC for linear range, slope , correlation coefficient , limit of detection, and optimum pH range and temperature respectively using internal filling solution of 10-3 M. The life time of the electrode was32 days .Spectrophotometric Method :The drug METO was determined by oxidative coupling reaction using 1 ml of 0.01M sodium periodate and 1.5 ml of the promethazine reagent (1000 μg.ml-1) , the absorption of the colored product is measured at 413 nm. .The molar absorptivity was 6873.42 L.mole-1.cm-1 and Sandel index 0.05154 μg.cm-2 . These methods were successfully applied for the determination of (METO) in Metoclopramide comprimes BP pharmaceutical preparations with recovery of not less than 97 % for the linear concentration range of 5 – 50 μg.ml-1.