scholarly journals Potentiometric Determination of Ketotifen Fumarate in Pharmaceutical Preparations and Urine Using Carbon Paste and PVC Membrane Selective Electrodes

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Eman Y. Z. Frag ◽  
Gehad G. Mohamed ◽  
Mohamed M. Khalil ◽  
Mohammad M. A. Hwehy

This study compares between unmodified carbon paste (CPE; the paste has no ion pair) and polyvinyl chloride (PVC) membrane selective electrodes that were used in potentiometric determination of ketotifen fumarate (KTF), where sodium tetraphenylborate (NaTPB) was used as titrant. The performance characteristics of these sensors were evaluated according to IUPAC recommendations which reveal a fast, stable, and linear response for KTF over the concentration range of 10−7to 10−2 mol L−1. The electrodes show Nernstian slope value of and  mV decade−1for CPE and PVC membrane electrodes at 30∘C, respectively. The potential is nearly stable over the pH range 3.0–6.0 and 2.0–7.0 for CPE and PVC membrane electrodes, respectively. Selectivity coefficient values towards different inorganic cations, sugars, and amino acids reflect high selectivity of the prepared electrodes. The electrodes responses at different temperatures were also studied, and long operational lifetime of 12 and 5 weeks for CPE and PVC membrane electrodes, respectively, were found. These are used for determination of ketotifen fumarate using potentiometric titration, calibration, and standard addition methods in pure samples, its pharmaceutical preparations (Zaditen tablets), and biological fluid (urine). The direct potentiometric determination of KTF using the proposed sensors gave recoveries % of and with RSD 1.42 and 0.63% for CPE and PVC membrane selective electrodes, respectively. Validation of the method shows suitability of the proposed sensors for use in quality control assessment of KTF. The obtained results were in a good agreement with those obtained using the reported spectrophotometric method.

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3150
Author(s):  
Fatehy M. Abdel-Haleem ◽  
Sonia Mahmoud ◽  
Nour Eldin T. Abdel-Ghani ◽  
Rasha Mohamed El Nashar ◽  
Mikhael Bechelany ◽  
...  

Levofloxacin (LF) is a medically important antibiotic drug that is used to treat a variety of bacterial infections. In this study, three highly sensitive and selective carbon paste electrodes (CPEs) were fabricated for potentiometric determination of the LF drug: (i) CPEs filled with carbon paste (referred to as CPE); (ii) CPE coated (drop-casted) with ion-selective PVC membrane (referred to as C-CPE); (iii) CPE filled with carbon paste modified with a plasticizer (PVC/cyclohexanone) (referenced as P-CPE). The CPE was formulated from graphite (Gr, 44.0%) and reduced graphene oxide (rGO, 3.0%) as the carbon source, tricresyl phosphate (TCP, 47.0%) as the plasticizer; sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate (St-TFPMB, 1.0%) as the ion exchanger; and levofloxacinium-tetraphenylborate (LF-TPB, 5.0%) as the lipophilic ion pair. It showed a sub-Nernstian slope of 49.3 mV decade−1 within the LF concentration range 1.0 × 10−2 M to 1.0 × 10−5 M, with a detection limit of 1.0 × 10−5 M. The PVC coated electrode (C-CPE) showed improved sensitivity (in terms of slope, equal to 50.2 mV decade−1) compared to CPEs. After the incorporation of PVC paste on the modified CPE (P-CPE), the sensitivity increased at 53.5 mV decade−1, indicating such improvement. The selectivity coefficient (log KLF2+,Fe+3pot.) against different interfering species (Na+, K+, NH4+, Ca2+, Al3+, Fe3+, Glycine, Glucose, Maltose, Lactose) were significantly improved by one to three orders of magnitudes in the case of C-CPE and P-CPE, compared to CPEs. The modification with the PVC membrane coating significantly improved the response time and solubility of the LF-TPB within the electrode matrix and increased the lifetime. The constructed sensors were successfully applied for LF determination in pharmaceutical preparation (Levoxin® 500 mg), spiked urine, and serum samples with high accuracy and precision.


2018 ◽  
Vol 24 (22) ◽  
pp. 2625-2630 ◽  
Author(s):  
Marwa F. Mansour ◽  
Mona M. Abd El-Moety ◽  
Ehab F. El Kady ◽  
N.M. El Guindi ◽  
Ann Van Schepdael ◽  
...  

Background: The application of an ion selective technique for the determination of analyte concentrations is considered one of the most economical techniques for quality control purposes. Objective: To elaborate and investigate the construction and general performance characteristics of potentiometric PVC membrane sensors for venlafaxine cation (Ven+). Method: The sensors are based on the use of the ion association complexes of the venlafaxine cation with phosphotungstate (PT) and silicotungstate (ST) counter anions as ion exchange sites in the plasticized PVC matrix. They are characterized by potentiometric and conductimetric measurements, performed under various conditions. Results: The electrodes showed a fast (response time around 15 s), stable (life span 45 days) and linear (r2 0.995) response for venlafaxine over the concentration range of 5x10-5 - 1x10-2 M venlafaxine hydrochloride. The solubility product of the ion pair and the formation of the precipitation reaction leading to the ion pair, were determined conductimetrically. The electrodes were found to be very selective, precise (RSD < 1%) and applicable to the potentiometric determination of venlafaxine hydrochloride in pure solutions or in pharmaceutical preparation and in biological fluid (serum), without any interference. Validation of the method shows the suitability of the proposed electrodes for use in the quality assessment of venlafaxine hydrochloride. Conclusion: Using only a pH meter in combination with the selective electrodes, drug substance or drug product could be determined accurately in a few seconds. In addition, the in-house made electrodes were tested to monitor venlafaxine in serum. Acceptable results were achieved using the standard addition technique.


RSC Advances ◽  
2015 ◽  
Vol 5 (102) ◽  
pp. 83657-83667 ◽  
Author(s):  
M. M. Khalil ◽  
Y. M. Issa ◽  
G. A. El Sayed

This article describes characteristics, performance and application of hydroxychloroquine (HCQ) polymeric membrane (PMEs) and modified carbon paste (CPEs) electrodes which are based on sodium tetraphenylborate (NaTPB) or ammonium reineckate (Rt) as sensing materials.


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