Application of green methodology to pharmaceutical analysis using eco-friendly ethanol-water mobile phases

A Green Approach: Optimization of the UPLC Method Using DoE Software for Concurrent Quantification of Pioglitazone and Dapagliflozin in a SNEDDS Formulation for the Treatment of Diabetes

Clinical trials revealed that pioglitazone (PGZ) and dapagliflozin (DGZ) not only maintain normal blood glucose levels but also reduce complications of diabetes mellitus. To meet the demand for simultaneous measurement of these drugs in fixed combinations, an optimized and green UPLC method is required. The present study utilized Design of Experiments (DoE) software to optimize analytical parameters for simultaneous drug analysis. The method was validated for its linearity, accuracy, and precision. Furthermore, the drug content was estimated in different pharmaceutical dosage forms. Finally, Analytical Greenness (AGREE) software was utilized to assess the environmental sustainability of the optimized UPLC method. Drugs were successfully separated using optimized conditions on the C18 Acquity BEH column (2.1 mm × 100 mm, 1.7 μm) at a temperature of 45 °C. The mobile phase consisted of ethanol and 9 mM ammonium formate buffer (43.7:56.3), with elution carried out at a flow rate of 0.246 mL/min. The optimized method showed excellent linearity (R 2 > 0.999), accuracy (92.45-109.25%), and good precision (RSD < 6.27%) for both drugs. In addition, the optimized UPLC method was able to determine the drug content within the marketed pharmaceutical dosage form accurately. The developed UPLC method also prioritized eco-friendliness by using green solvents to minimize the negative impact on the environment. The green UPLC method provides a reliable and accurate approach to estimate PGZ and DGZ in a fixed diabetes treatment combination. It promotes sustainable lab practices and paves the way for analytical methods for new dose combinations.

Fast and green universal method to analyze and quantify anthocyanins in natural products by UPLC-PDA

This work developed a universal UPLC-PDA method based on safe reagents to analyze anthocyanins from different foods. Nine foods were studied by the developed chromatographic method, which was constructed using a solid core C18 column and a binary mobile phase composed of (A) water (0.25 mol_{citric acid}.L_solvent^-1), and (B) ethanol. A total running time of 6 min was obtained, the faster comprehensive method for anthocyanins analysis. Mass spectrometry analysis was employed to identify a comprehensive set of 53 anthocyanins comprising glycosylated and acylated cyanidin, pelargonidin, malvidin, peonidin, petunidin, and delphinidin derivatives. Cyanidin-3-O-glucoside (m/z⁺ 449) and cyanidin-3-O-rutinoside (m/z⁺ 595) were used as standards to validate the accuracy of the developed method. The analytical parameters were evaluated, including intra-day and inter-day precision, robustness, repeatability, retention factor (k), resolution, and peak symmetry factor. The current method demonstrated excellent chromatographic resolution, making it a powerful tool for analyzing anthocyanins pigments.

Combining environmental, health, and safety features with a conductor like Screening Model for selecting green solvents for antibiotic analyses

Extraction and chromatographic techniques for analyzing pharmaceutically active compounds necessitate large quantities of organic solvents, resulting in a high volume of hazardous waste. The concept of green solvents focuses on protecting the environment by reducing or even eliminating the use of toxic solvents. The main objective of this critical review article is to build a framework for choosing green solvents for antibiotic analyses. The article briefly discusses the chemical properties of ciprofloxacin, sulfamethoxazole, tetracycline, and trimethoprim, and the current state of methodologies for their analyses in water and wastewater. It evaluates the greenness of solvents used for antibiotic analyses and includes insights on the comparison between conventional and green solvents for the analyses. An economic and environmental health and safety analysis combined with a Conductor-like Screening Model for Real Solvent (COSMO-RS) molecular simulation technique for predicting extraction efficiency was used in the evaluation. Methyl acetate and propylene carbonate tied for the greenest solvents from an environmental and economic perspective, whereas the COSMO-RS approach suggests dimethyl sulfoxide (DMSO) as the most suitable candidate. Although DMSO ranked third environmentally and economically, after methyl acetate and propylene carbonate, it would be an ideal replacement of hazardous solvents if it could be manufactured at a lower cost. DMSO showed the highest extraction capacity, as it can interact with antibiotics through hydrophobic interaction and hydrogen bonding. This article can be used as a green solvent selection guide for developing sustainable processes for antibiotic analyses.

Multiple Heart-Cutting Two-Dimensional HPLC-UV Achiral–Chiral Analysis of Branched-Chain Amino Acids in Food Supplements under Environmentally Friendly Conditions

A multiple heart-cutting (mLC-LC) two-dimensional HPLC-UV achiral–chiral method for the direct analysis of branched-chain amino acids (BCAAs) in food supplements under environmentally friendly conditions was developed to cope with the very well-known limited chemoselectivity of chromatographic media for enantioselective analysis. Both achiral and chiral methods were developed in compliance with the main principles of green chromatography. The achiral analysis was performed isocratically with an optimized ion-pair reversed-phase (IP-RP) method based on a water/EtOH (95:5, v/v) mobile phase containing heptafluorobutyric acid (7 mM) as the IP agent. The achiral method was characterized by a very appreciable performance and was validated before the analysis of the real sample. High recovery values for all compounds (from 97% to 101%) were found in the interday evaluation. Additionally, low RSD% values in the long-term period were measured, in the range between 1.1% and 4.8%. Still, an LOQ value of 0.06 mg/mL was established for all compounds. The quantitative analysis of a commercial food supplement revealed that BCAAs were present in amounts very close to those declared by the producer. The enantioselective analysis was carried out through the application of the chiral ligand-exchange chromatography (CLEC) approach, using O-benzyl-(S)-serine ((S)-OBS, 0.5 mM) as the chiral selector and Cu(II) nitrate (0.25 mM) as the metal source in the eluent. Resolution and separation factor values up to 2.31 and 1.43, respectively, were obtained. The two chromatographic systems were connected through a six-port switching valve, and the developed two-dimensional mLC-LC method confirmed the absence of D-enantiomers of BCAAs in the food supplement, as reported in the manufacturer’s label.

Sweeping-micellar electrokinetic chromatography versus reversed phase liquid chromatography for the determination of coumarin in curry

Coumarin is a phytotoxin found in the popular spice cinnamon, which is used to flavor many Asian curry dishes. In this work, we developed and compared the analytical performance of reversed-phase liquid chromatography (RP-LC) and sweeping-micellar electrokinetic chromatography (MEKC) methods for the determination of coumarin in complex curry (gravy) samples. Using a matrix matched sample (curry after solvent extraction with methanol and diluted with 100 mM phosphoric acid), the intra-day and inter-day repeatability of retention/migration time and (corrected) peak area for both methods were acceptable (%RSD (n=6) ≤ 5%). The linear range and limit of quantitation (LOQ) were an order of magnitude better in RP-LC (RP-LC linear range = 0.11-108 mg/kg, LOQ = 0.11 mg/kg) (Sweeping-MEKC linear range = 2.16-216 mg/kg, LOQ = 2.16 mg/kg). However, the limit of detection (S/N=3) and LOQ in sweeping-MEKC was 0.65 mg/kg and 2.16 mg/kg, which were sufficient to report the levels of coumarin ≥ the European limit of 2 mg/kg in foods. During the analysis of 25 curry samples, relatively similar results for sweeping-MEKC and RP-LC were obtained for 6 samples that contained coumarin >LOQ of sweeping-MEKC. Interferences in RP-LC lead to significant overestimation of coumarin levels in 3 samples. Coumarin levels above the EU limit was found in 6 curry samples using the more selective sweeping-MEKC. This work should also raise public awareness on the presence of potentially high levels of coumarin in some foods.

Elemental sulphur in the synthesis of sulphur-containing polymers: reaction mechanisms and green prospects

The synthesis of polymers using elemental sulphur as a chemical agent has been studied in relation to the worldwide overproduction of cyclo-octasulphur. Herein, the mechanisms of the processes leading to the inclusion of elemental sulphur into macromolecules have been reviewed and the main methods for reduction of the reaction temperature required for the S8 ring opening have been shown. Approaches to the activation of cyclo-octasulphur in the synthesis and macromolecule cross-linking reactions were discussed in the context of finding the chemical agents and conditions that satisfy the principles of green chemistry.