Year: 2018
Type: article
Abstract: This paper presents the design and fabrication of a potentiometric sensor for the determination of carbachol in ophthalmic solutions.Carbachol is the active ingredient in certain ophthalmic solutions and its concentration must be maintained to provide its expected therapeutic result during the treatment of glaucoma.Carbachol is an analytically challenging molecule to measure because it lacks a detectable chromophore and is redox-inactive.This work demonstrates the first use of potentiometry to measure carbachol using an ion-selective electrode (ISE).Incorporating calix[4]resorcinarene as an ionophore resulted in a lower limit-of-detection (0.12 μM), larger linear response range (1 μM-10 mM), and enhanced selectivity when compared to the ionophore-free ISE.The ISE was used for direct detection of carbachol in a commercially available ophthalmic solution (without sample separation and pre-treatment steps), and the results were validated using the official US pharmacopeia benchmark method.To expand the application of this sensor, we performed real-time monitoring of carbachol's degradation, allowing for the calculation of the activation energy of its hydrolysis, an important parameter when estimating a drug's shelf-life.
DOI: 10.1149/2.0571816jes
Institutions: Harvard University, University of Minnesota, Cairo University
Language: English
Subfield: Bioengineering
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2903903498