Chromatographic determination of sulfasalazine and its active metabolites: greenness assessment and application to spiked human plasma

Study on the Rapid Limit Test for Six Sulfonamide Residues in Food Based on the TLC-SERS Method

Sulfonamides are not only widely applied in clinics but also highly valued in animal husbandry. Recently, it has become common for sulfonamide residues to exceed the standard limits in food, which can affect human health. Current regulations limit these residues. Therefore, we constructed a new limit test method to rapidly determine the levels of sulfonamide residues. Six sulfonamides were detected using the latest method called TLC-SERS, namely, sulfamethasone (A), sulfamethazine (B), sulfadoxine (C), sulfamethoxydiazine (D), sulfamethoxazole (E), and sulfathiazole (F). The optimal conditions for SERS detection were investigated for these six drugs, and the separation effects of different TLC spreaders on them were compared. Then, we successfully established a separation system using dichloromethane-methanol-ammonia in a ratio of 5:1:0.25 (v/v/v), which provided good separation effects on the six drugs. The residues were preliminarily separated via TLC. A silver sol solution was added to the spot on the silica gel G plate at the corresponding specific shift values, and SERS detection was performed. The sample solution was placed on the spot under a 532 nm laser, and the SERS spectrum was collected and analyzed for the six sulfonamides. The results showed obvious variations in the SERS spectrum among the six sulfonamides, with the LODs being 12.5, 6.4, 6.3, 7.1, 18.8, and 6.2 ng/mL from A to F, respectively, and an RSD of <3.0%. Within 48 h, the SERS signal for each sulfonamide drug was kept stable, with an RSD of <3.0%. The detection results of 20 samples using the TLC-SERS method were consistent with those obtained by UPLC-MS/MS. The established TLC-SERS method is simple and fast, providing a useful reference for the rapid detection of residue limits in food.

Development of HPLC-UV Method for Simultaneous Determination of Corticosteroid Co-Administered Immune Therapy

Prednisolone (PDS) has recently been utilized to treat a variety of medical disorders, including autoimmune illnesses and cancer. It is also used to treat coronavirus disease 2019 infection-related respiratory problems. Because it may induce health problems including gastrointestinal lesions and ulceration, it has to be used alongside other drugs like esomeprazole (ESM), which acts as a proton pump antagonist to reduce the probability of ulceration. As a result, the goal of this research is to create an environmentally safe and sensitive high-performance liquid chromatography (HPLC) approach for determining PDS and ESM in their binary combination and spiked human plasma. C8 column (100 × 4.6 mm, 5 μm) and gradient mobile phase elution were used to separate the studied drugs with ultraviolet recognition at 290 nm. Caffeine was utilized as an internal standard to adjust the sample variance. Plasma, caffeine, ESM and PDS all had tR values of 1.4, 3.5, 6.3 and 7.3, respectively. The suggested method's greenness features were evaluated using three greenness evaluation tools: green analytical procedure index, analytical greenness metric approach and analytical eco-scale, and the findings were approved and satisfied. Validation parameters were evaluated in accordance with US-FDA recommendations in order to meet the global desires for biological analysis technique, acceptable limits were obtained.

A validated ecofriendly chromatographic method for determination of myasthenia gravis combined medications in spiked human plasma

Recently, the main interest of analytical chemistry researchers has been the development of green analytical methods to minimize harmful effects on the environment and natural life. Therefore, an RP-HPLC method was developed and assessed regarding its greenness criteria using three greenness assessment tools: an analytical eco-scale, an analytical greenness metric approach and a green analytical procedure index. This method aims to separate and quantitatively determine three co-administered drugs, namely pyridostigmine bromide (PYR), 6-mercaptopurine (MRC) and prednisolone (PRD), in their tertiary mixture and spiked human plasma. These drugs are co-administered to manage myasthenia gravis autoimmune disease. The separation was done using a C₁₈ column and a gradient elution of a mixture of 0.1% H₃ PO₄ aqueous solution (pH 2.3) and methanol. The flow rate was adjusted to 1 ml/min and detection was done at 254 (for PYR and PRD) and at 330 nm (for MRC). The lower limits of quantitation were 15, 2, and 5 μg/ml for PYR, MER and PRD, respectively. Linear correlations were obtained and found to be near 1. In addition, the proposed method was validated according to the US Food and Drug Administration's instructions, and the results proved its success to determine the three studied drugs in their tertiary mixture and spiked human plasma.

Four Greenness Evaluations of Two Chromatographic Methods: Application to Fluphenazine HCl and Nortriptyline HCl Pharmaceutical Combination in Presence of Their Potential Impurities Perphenazine and Dibenzosuberone

Nowadays, when analysts develop a new method, they are taking into consideration the green aspects of the developed method. Two chromatographic methods were developed for the determination of antidepressant pharmaceutical combination nortriptyline hydrochloride and fluphenazine hydrochloride in presence of their potential impurities and the methods were assessed using four tools; eco-scale, analytical greenness profile (AGP), analytical greenness metric approach (AGREE), and green analytical procedure index (GAPI). Method (A) was RP-HPLC, in which the separation was carried out on C18 column (250 × 4.5 mm, 5 µm) by gradient elution using mobile phase consisting of a mixture of water containing 0.1% H3PO4 (pH 2.25) and methanol, at a flow rate of 2 mL/min with DAD detection at 254 nm. Method (B) was TLC, in which the separation was carried out on silica gel TLC F254 plates. The mobile phase used was a mixture of methanol and acetone (9:1, v/v) with UV detection at 245 nm. The proposed methods agreed with ICH guidelines of method validation and were successfully applied for determination of the proposed components in their dosage form and the results were compared statistically to those obtained by the reported RP-HPLC method with no significant difference; which suggests the application of the developed methods for routine quality control analysis of these drugs.

Extended suspect screening to identify contaminants of emerging concern in riverine and coastal ecosystems and assessment of environmental risks

A suspect screening methodology was developed for the fast and reliable identification of 360 contaminants of emerging concern (CECs) of anthropogenic origin in the vulnerable area of the Ebro Delta (Catalonia, Spain) and to track for potential contamination sources. The suspect screening methodology was combined with a risk assessment approach to prioritize the most ecologically relevant CECs. Out of the 360 suspects, 37 compounds were tentatively identified, 22 of which were fully confirmed using isotopically labelled standards. The detected suspect compounds included pesticides, pharmaceuticals, personal care products, stimulants and their metabolites. Pesticides were more ubiquitous in irrigation and drainage channels, while pharmaceuticals, stimulants, and personal care products were the most common in effluent wastewaters, in the receiving freshwater systems as well as in the marine environment. Ten compounds were found to be of high ecological concern, including the pharmaceuticals telmisartan, venlafaxine, and carbamazepine, the herbicides terbuthylazine, desethylterbuthylazine, and terbutryn, the fungicides azoxystrobin, tebuconazole and prochloraz and the insecticide tebufenozide. These compounds could be used as markers of anthropogenic contamination in riverine and coastal ecosystems.

Characteristics, Properties and Analytical/Bioanalytical Methods of 5-Aminosalicylic Acid: A Review

Five-aminosalicylic acid (5-ASA) is an anti-inflammatory drug indicated in the treatment of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. Among the analytical methods of quantification of 5-ASA described in the literature, the High Efficiency Liquid Chromatography stands out, a sensitive technique but with a high cost. In recent years, alternative methods have been developed, presenting efficiency and reduced cost, such as UV/visible spectrophotometric, spectrofluorescent, and electrochemical methods, techniques recommended for the application in quality control and quantification of 5-ASA in pharmaceutical forms and biological fluids. This article aims to review the physicochemical characteristics, pharmacokinetics, mechanisms of action, controlled release systems, and the different analytical and bioanalytical methods for the quantification of 5-ASA.