Green methods for the simultaneous analysis of pharmaceutical mixtures present in disparate concentration ranges: Application to antidiabetic mixtures

Recent developments in electromigration techniques related to pharmaceutical and biomedical analysis - A review

The analysis of pharmaceutical compounds is an important research topic as the use of different drugs affects people's daily life for the treatment of diseases. In addition to the widespread use of the internet, counterfeit drugs have appeared in the market. The development of modern analytical techniques, reliable, precise, sensitive, and rapid methods, has provided powerful means of analysis used in various fields such as drug production, quality control, determination of impurities and/or metabolites, biochemistry, pharmacokinetics, etc. Analytical techniques so far used in the pharmaceutical analysis include high-performance liquid chromatography (HPLC), gas chromatography (GC), super/sub-critical fluid chromatography (SFC), and capillary electromigration techniques such as capillary electrophoresis (CE) and rather rarely capillary electrochromatography (CEC). CE has some advantages over other techniques, e.g., very high efficiency, reduced costs (use of minute volumes of solvents and samples), the possibility to use different separation mechanisms, etc. In this review paper, the main features and limitations of the capillary electromigration techniques (especially CE) are discussed. Some selected applications of CE to the analysis of pharmaceutical compounds published in the period 2021-2023 (May) are reported.

Green and white MEKC for determination of different anti-diabetic binary mixtures and their triple-combo pill

The work introduces green and white sustainable micellar electrokinetic chromatography (MEKC) procedure that could analyze therapeutically related drugs, empagliflozin (EMP), linagliptin (LIN) and metformin (MET) which are antidiabetic drugs with different mechanism of action, in their different pharmaceutical combinations. The method not only comply with the green analytical concepts, but also it is in line with sustainable analytical concepts as it is economic by applying the same operating conditions to analyze different pharmaceuticals in quality control (QC) labs which is a crucial step in QC labs and research centers to save time, effort, and money. Moreover, the method functionality regarding its scope with its achieved levels of accuracy, precision, low detection, and quantitation limits is tested using white assessment tool and compared with reported methods. The proposed MEKC coupled with a diode array detector (DAD) has been developed and validated for micro estimation of EMP and LIN in their low critical concentrations with MET in a ratio of (EMP: MET, 1:40) and (LIN: MET, 1:200). Separation was achieved within 6 min using fused silica capillary (40 cm × 50 µm id) using 20 mM Tris buffer (pH 10) in presence of 50 mM sodium dodecyl sulphate and 10% v/v methanol. The concentration ranges of the studied anti-diabetic drugs were 10-500, 10-100 and 2.5-100 µg. mL^-1 for MET, EMP and LIN, respectively. The developed method is the first MEKC for concurrent determination of EMP, LIN and MET with high separation efficiency, low solvent consumption and regard as an easy green and white analytical tool. Moreover, Greenness and whiteness assessment were done via the most widely used Analytical Eco-Scale, the innovative AGREE tool and the RGB 12 algorithm.

Simple simultaneous determination of moxifloxacin and metronidazole in complex biological matrices

A simple, sensitive and rapid RP-HPLC method is presented, for the first time, for the simultaneous determination of moxifloxacin hydrochloride and metronidazole in different biological fluids including saliva and plasma without any matrix interference. The separation was performed using ACN and phosphate buffer (30 : 70% v/v) as the mobile phase on a Zorbax Eclipse Plus-C18 column attached to a guard column. The method was validated according to the FDA guidelines for bioanalytical method validation and was successfully applied for simultaneous determination of the studied drugs in saliva and plasma samples. The good precision and selectivity of the developed method allow it to be used for routine therapeutic drug monitoring of such drugs and it presents a simple and sensitive analytical tool for performing versatile pharmacokinetics and bioavailability studies. A DAD detector is valuable to determine each drug at its maximum wavelength to ensure high sensitivity. Determination of such a combination in saliva introduces a quick and non-invasive alternative to blood analysis.

In situ green analytical methods for the rapid and sensitive determination of a newly launched orphan anticancer drug; Tigecycline in infusion bags: comparative study

Background

Tigecycline (TIG), an antimicrobial agent indicated for complex bacterial infections, is now approved by FDA as an orphan chemotherapeutic agent for the treatment of acute myeloid leukemia due to its inhibitory effects on pathways of activating, signaling and abnormal mitochondrial function in cancer cells. TIG is mainly administered as intravenous infusion through centralized unit of oncology centers. This necessitates the continuous analytical quality control of the prepared solution in order to identify and quantify TIG for safe intravenous administration to patients. Moreover, the clinical staff exposure risk to toxic drugs during daily handling must be considered. Such concerns require a fast, cost-effective and green analytical procedure for sensitive determination of TIG directly in infusion bags. In this work, we propose a simple, rapid and green capillary zone electrophoretic (CZE) method for the sensitive assay of TIG directly in infusion bags, in addition to three simple and green spectrophotometric methods.

Results

TIG solutions corresponding to clinical ranges were detected in 5%glucose. Validation of all the proposed methods was according to ICH guidelines. Greenness assessment was performed depending on Green Analytical Procedure Index (GAPI) and the Eco-scale approach which showed that the proposed methods are better eco-friendly methods than reported ones. It also revealed the superiority of our proposed methods in terms of simplicity and sensitivity for TIG determination in infusion bags. Quantification limits obtained were significantly lower than the administered range of TIG in infusion bags and lower than its maximum serum concentration (Cmax). This promotes the application of the proposed methods for the pharmacokinetics and bioavailability studies of TIG in various biological fluids.

Conclusions

This work reports, for the first time, CZE method for the direct and rapid determination of TIG and its separation from other components in intravenous infusion solution. The developed CZE method has several advantages over current chromatographic methods such as higher efficiency of separation within short analysis time, consumption of fewer quantities of chemicals and offering better resolution than HPLC. Moreover, three green spectrophotometric methods are also proposed for TIG determination that offer many advantages such as accuracy, precision, simplicity, specificity and facility of quantification and separation of the selected drug in infusion bags and pharmaceutical preparations without any techniques for extraction.