Mohamed K. Abd El-Rahman

Mivacurium chloride is envisioned as the “gold-adjunct” in anesthesia and emergency medicine. People across the world are administered mivacurium in emergency situations as clinicians prefer it among the frequently used neuromuscular blockers thanks to its rapid action and short duration. Mivacurium is promptly degraded and deactivated by plasma cholinesterase enzyme (PChE), however during emergency situations, some individuals were found to be unable to metabolize mivacurium shortly after its injection, resulting in prolonged paralysis and potentially lethal respiratory apnea. The most clinically significant cause of this residual paralysis and apnea is the reduced cholinesterase ability to effectively hydrolyze mivacurium. Hitherto, monitoring of mivacurium enzymatic degradation has been remaining a long-standing challenge for analytical chemists as well as anesthesiologists. Firstly, it undergoes rapid hydrolysis by the PChE-enzyme 8 min post-injection, therefore, frequent sampling all through the first minutes after mivacurium administration is mandatory. Secondly, its isolation from biological specimens is extremely difficult due to its chemical properties which involves both hydrophilic and lipophilic characteristics. These challenges impede the development of a universal protocol to be established for screening of PChE-activity towards mivacurium and which clearly identifies patients susceptible to prolonged paralysis. In this study, we designed a point-of-care (PoC) potentiometric sensor that can perform tracking of mivacurium enzymatic degradation kinetics with high accuracy and rapidly. Real serum samples were utilized for in vitro estimation of the rate of mivacurium metabolism, where values of 227 μmol l−1 and 62 μM min−1 were obtained for the characteristic parameters of the enzymatic reaction, Km and Vmax, respectively. Correlation of the results obtained using the proposed approach and earlier LC-MS/MS study is shown.

Recent improvements in miniaturization of the existing technologies, nevertheless analytical instruments have acquired worldwide acceptance and encouragement. The replacement of traditional analytical procedures by miniaturized alternatives has become inevitable to promote more ecologically benign techniques. The dominance of HPLC technique during the past decades is noticeable in the fields that deal with drugs’ analysis and quality control despite the provoked environmental concerns about it. Thus, the development of a miniaturized HPLC that retains the practicality and versatility of the conventional HPLC technique, whereas it is greener, has been a long thought after goal for the analysts. Lately, UPLC has been developed as a unique analytical approach that utilizes the chemistry of small particles to meet the need for a miniaturized HPLC methodology. Employing a smaller sized stationary phase that can withstand high pressure, UPLC leads to a substantial reduction in time, labor, waste, and cost of materials required to get results compared to traditional HPLC columns. In this contribution, a UPLC method was adopted for the first time for the analysis and purity assessment of a binary mixture of ebastine (EBS) and phenylephrine hydrochloride (PHE) formulated in Ebast DC® tablets. The proposed UPLC method was applied successfully to the determination of the investigated drugs over a linearity range of 1–50 µg/mL, with LODs equal to 0.31 µg/mL and 0.33 µg/mL for EBS and PHE, respectively. To evaluate the greenness of the developed UPLC methodology; the Eco-Scale semi-quantitative green metric tool was employed in a side-by-side comparison with the reported HPLC method to conclude whether UPLC provides a greener and more efficient technique or not.