Green monitoring of bromhexine oxidative degradation kinetics

H. A. Merey, S. S. El-Mosallamy, N. Y. Hassan, and B. A. El-Zeany, "Green monitoring of bromhexine oxidative degradation kinetics", Microchemical Journal, vol. 152, pp. 104378, 2020.


Kinetics studies are important in quality control to assure the safety and efficacy of the pharmaceutical compounds.
Recently, potentiometric ion-selective electrodes (ISEs) breakthrough kinetics study due to their ability
to provide real-time measurements which meet “green analytical chemistry” (GAC) principles. A polyvinyl
chloride (PVC) matrix membrane was fabricated to monitor bromhexine (BR) oxidative degradation kinetics
using tetraphenylborate as a cation exchanger. At-line monitoring of the oxidative degradation kinetics of BR was
performed; by continuous measuring the decrease in the sensor potential over time. So a real-time observation
and a continuous profile were obtained for the oxidation of BR under various H2O2 concentrations and temperature.
This kinetic study determines the oxidation activation energy that was 6.4 kcal mol−1. To expand the
application of this sensor, BR was determined in bulk powder and dosage form in the presence of both coformulated
drug (acefylline piperazine) and dosage form additives. The proposed sensor had been characterized
according to IUPAC recommendations and a linear dynamic range was 5×10−6 to 1×10−3M and other sensor
parameters had been calculated.