Author/Authors :
Abd El-Rahman Mohamed K . نويسنده Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt , Lotfy Hayam M . نويسنده Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt , Hegazy Maha A . نويسنده Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt , Rezk Mamdouh R . نويسنده Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt , Rostom Omran Yasmin نويسنده Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt
Abstract :
A novel electrode was developed for potentiometric determination of dexamethasone sodium phosphate (DSP) using tetraheptyl ammonium bromide (THB) as an anionic exchanger in polyvinyl chloride (PVC) matrix and 2-nitrophenyl octyl ether (2-
NPOE) as a plasticizer. Linear responses of 1×10?5 to 1×10?2 M with slope of -26.50±0.39
mV/decade within working pH range 8-12 were achieved. The percentage recovery of
determination of DSP by the proposed DSP selective electrode was 99.96±0.95.
Determination of DSP in its pharmaceutical formulations by the proposed electrode revealed
its applicability for determination. Moreover, the electrode exhibits good selectivity for DSP
with respect to a large number of interfering substances and co-formulated drugs. The
fabricated sensor was validated according to ICH guidelines and successfully applied for
determination of the studied drug in pure form and pharmaceutical formulations without any
interference from additives either labeled or non-labeled. The obtained results have been
statistically compared to that of an official spectrophotometric method to give a conclusion
that there is no significant difference between the proposed methods and the official one with
respect to accuracy and precision
