Development of a solvent-free micellar HPLC method for determination of five antidiabetic drugs using response surface methodology

Eco-conscious chromatographic determination of an anti-depressant free-dose combination in the presence of related impurities

According to the World Health Organization (WHO), an estimated 10% of pharmaceutical products distributed in developing countries are counterfeit or of substandard quality. A crucial strategy to help overcome this problem is to develop simple and easily applicable analytical methods for quality control testing of drugs, especially those administered in combinations due to their complex nature. Here, we worked towards this goal through the development of a simple, and rapid method based on High Performance Liquid Chromatography coupled with Ultraviolet detection (HPLC-UV) for the simultaneous determination of an anti-depressant free-drug combination consisting of brexpiprazole (BREX) and fluoxetine (FLX) in the presence of fluoxetine related impurities (FLX-A). Chromatographic separation was carried out employing a mixture of 45% ethanol and 55% aqueous solvent consisting of 0.1% triethylamine, 0.15 M sodium dodecyl sulfate and 0.057 M sodium dihydrogen phosphate adjusted to pH 6 using orthophosphoric acid. Separation was performed using a hypersil BDS C18 column at 50 °C, employing isocratic elution; the flow rate was set at 1.5 mL min-1, and UV detection was performed at 220 nm. The results of the developed method reflect excellent analytical performance. Linearity was observed over a concentration range of 5-80 μg mL-1 for both drugs with correlation coefficients of 0.9996 and 0.9998 for BREX and FLX, respectively. The respective LOQ and LOD values were found to be 2.70 and 4.41 μg mL-1 and 0.83 and 1.46 μg mL-1 for BREX and FLX; in addition, the developed method was utilized to test the purity of both drugs in pharmaceutical formulations by monitoring fluoxetine-related impurities. The developed method was also determined to be eco-friendly, as testing with four available assessment tools demonstrated its superior greenness, especially represented by an AGREE score of 0.83.

Leveraging Green Chromatography in Quality-by-Design-Driven Study for the Simultaneous Analysis of Essential Single-Pill Antidiabetic Drug Combinations

Micellar liquid chromatography (MLC) has proven beneficial efficiency and ecological impact for routine quality control activities. In the proposed study, cyrene was investigated for the first time, together with other green additives, as a novel safe organic solvent in reversed-phase MLC. Quality-by-design (QbD) approach screened their effect on the separation performance. Six antidiabetic drugs from different classes, namely, metformin (MTF), empagliflozin (EMP), ertugliflozin (ERT), linagliptin (LNT), sitagliptin (SIT), and gliclazide (GCZ) were utilized to assess some newly approved antidiabetic drugs and combinations. An organic solvent-free mobile phase consisting of (0.01 M Brij-35, 0.09 M sodium dodecyl sulfate, and 0.01 M ammonium acetate, pH 5.0) separated the studied drugs using an RP-C18 core-shell column. The flow rate was set at 1.2 mL/min, and analytes were detected using a photodiode array detector at 245, 270, and 225 nm. System suitability parameters demonstrated MLC capability to eliminate organic solvents without compromising separation efficiency. The method was validated across a concentration range of 2.0-30.0 µg/mL for EMP, ERT, and LNT, 20.0-120.0 µg/mL for GCZ and SIT, and 100.0-600.0 µg/mL for MTF. The method successfully determined analytes in different single and multicomponent tablets. Greenness assessment was performed using MoGAPI and AGREE metrics.

Central composite design driven optimization of sustainable stability indicating HPLC method for the determination of Tigecycline and greenness assessment

Background: Tigecycline (TGC) is a recently developed antibiotic to battle resistant bacteria. The procedures outlined in the literature for analyzing TGC involve chemical solvents that could be hazardous. Therefore, this study aimed to create a sustainable and stable HPLC technique for quantifying Tigecycline in lyophilized powder. The powerful chemometric tool, experimental design (ED), will be applied to analyze the variables' interaction and impact on the selected analytical target profiles. Response surface methodology provides a tutorial on using the central composite design with three levels of variables and quadratic programming to optimize the design space of the developed method. Methods: The New HPLC method consisted of an aqueous buffer and ethanol as a green mobile phase run on a reversed-phase symmetry C18 column. A full resolution between the Tigecycline and its degradation product peaks was achieved in a short analytical runtime. Results: Further, the specificity, accuracy, precision, robustness and stability indicating power of the proposed approach were verified through stress degrading testing. Conclusions: Finally, the analytical eco-scale and the green Analytical Procedure Index (GAPI) were utilized to determine how environmentally friendly the recommended method was compared to other published approaches.

Central composite design driven optimization of sustainable stability indicating HPLC method for the determination of Tigecycline and greenness assessment

Background: Tigecycline (TGC) is a recently developed antibiotic to battle resistant bacteria. The procedures outlined in the literature for analyzing TGC involve chemical solvents that could be hazardous. Therefore, this study aimed to create a sustainable and stable HPLC technique for quantifying Tigecycline in lyophilized powder. The powerful chemometric tool, experimental design (ED), will be applied to analyze the variables' interaction and impact on the selected analytical target profiles. Response surface methodology provides a tutorial on using the central composite design with three levels of variables and quadratic programming to optimize the design space of the developed method. Methods: The New HPLC method consisted of an aqueous buffer and ethanol as a green mobile phase run on a reversed-phase symmetry C18 column. A full resolution between the Tigecycline and its degradation product peaks was achieved in a short analytical runtime. Results: Further, the specificity, accuracy, precision, robustness and stability indicating power of the proposed approach were verified through stress degrading testing. Conclusions: Finally, the analytical eco-scale and the green Analytical Procedure Index (GAPI) were utilized to determine how environmentally friendly the recommended method was compared to other published approaches.

Development of green micellar HPLC-DAD method for simultaneous determination of some sulbactam combinations used in COVID-19 regimen

In a new attempt to separate some sulbactam combinations by green chemical method we came up with this research in which an ecofriendly, green, sustainable and selective method was established for separation of four antibiotics, namely, cefoperazone (CFP), cefixime (CFX), ampicillin (AMP) and sulbactam (SLB). No organic solvents were used in the composition of the mobile phase as it was replaced by mixing two surfactants together, sodium dodecyl sulfate (SDS) and polyoxyethylene-23-lauryl ether (Brij-35). Effect of varying the concentrations of the two surfactants on chromatographic separation was studied. Optimum separation was maintained using a mobile phase consisting of 0.01 mol/L SDS, 0.03 mol/L Brij-35, 0.4% Tri-ethylamine (TEA) and pH of 2.8 adjusted by using 1 M ortho-phosphoric acid on reversed phase Isère C18 BDS column with temperature of 40 °C at flow rate 1 mL/min, wavelength 215 nm, and the total run time was 6 min. Validation of the proposed method has been made according International Conference of Harmonization (ICH) guidelines at linearity range of 10-200 µg mL-1 for all drugs under study, high accuracy results (recovery range 98.39-100.35%). and the variation coefficient (RSD) of the points on the calibration curve was ranged from (0.1-1.7%) indicating precise method. The LOQ was (6.09 μg mL-1) for CFP, (6.07 μg mL-1) for CFX, (3.85 μg mL-1) for AMP and (7.20 μg mL-1) for SLB. Successful applications were made on marketed dosage forms with recovery range of (100.16-102.25%) and RSD of (0.03-1.88%). The method was verified on the Green Analytical Procedure Index (GAPI) and Analytical Greenness metric approach (AGREE) and it was found to be an excellent green alternative method.

Earth-friendly micellar UPLC technique for determination of four hypoglycemic drugs in different pharmaceutical dosage forms and spiked human plasma

A novel, sensitive, and green micellar UPLC method was proposed and validated for the simultaneous determination of four hypoglycemic agents used in type II diabetes mellitus treatment namely, pioglitazone, alogliptin, glimepiride, and vildagliptin. The developed UPLC method was successfully applied for quantitative analysis of these drugs in bulk, in pharmaceutical formulations, and in spiked human plasma. Chromatographic separation was carried out on a Kinetex® 1.7 μm XB-C18 100 Å (50 × 2.1 mm) column, using a degassed and filtered mixture of (0.1 M SDS- 0.3% triethyl amine- 0.1% phosphoric acid (pH 6)) and n-propanol (85:15 v/v), at a flow rate of 0.2 mL/min. The experimental conditions of the suggested method were well investigated and optimized. The newly developed micellar UPLC method is capable of determining different dosage forms at the same time with the same solvents, saving time and effort. The method was found to be efficiently applicable in spiked human plasma and could be extended to study the pharmacokinetics of the cited drugs in real human plasma samples. The greenness of the developed method was evaluated by applying the Eco-scale scoring tool, which verified the excellent greenness of the analytical method.

Design of an Experimental Study for the Simultaneous Determination of Cefepime, Piperacillin and Tazobactam Using Micellar Organic Solvent-Free HPLC

Application of Sustainable analytical chemistry concepts has become crucial in order to remove the environmentally harmful impacts originating from the routine use of analytical techniques. Here, a new LC method is developed and its parameters are analyzed, depending on a mixed micellar mobile phase. This was primarily aimed at getting rid of the use of organic solvents in conventional routine analyses. Combinations of tazobactam (TZB) with piperacillin (PPC) or cefepime (CFM) are commonly used as effective antimicrobial therapies, especially for resistant strains. Therefore, the three drugs were separated and quantified using an organic solvent-free mobile phase. The mixed micellar mobile phase was comprised of 15 mM Brij-35 with 38 mM SDS, adjusted to pH 3.5. Separation was performed by HPLC on monolithic RP-C18 column Chromolith® Performance RP-18e (100 mm × 4.6 mm) at a rate of 1 mL per minute of flow in conjunction with a measurement wavelength 210 nm. The method was found valid and applicable in accordance of precision, and accuracy within ranges of 5–100 µg mL−1 for PPC and CFM and of 0.625–12.5 µg mL−1 for TZB. The quality-by-design technique was used to analyze the effect of modifying the mixed micellar ratios on separation efficiency and conclude their behavior. Finally, the suggested approach was assessed applying the green analytical procedure index against the greenest published methodology to show superiority.