The Role of Vitamins, Magnesium, and Trace Elements in COVID-19 Treatment and Post-COVID-19 Rehabilitation: An Updated Overview.

This review summarizes the scientific knowledge concerning the impact of vitamins, magnesium, and trace elements on various mechanisms contributing to the possible treatment and prevention of COVID-19, including its delayed consequences. A search was conducted in various databases, including PubMed, Scopus, ClinicalTrials.- gov, and Web of Science. Among the main mechanisms involved in the effects of the studied micronutrients, immune-boosting, antioxidant and anti-inflammatory effects were also highlighted. The analyzed clinical trials confirmed that supplementation with higher daily doses of some micronutrients can reduce SARS-CoV-2 viral load and hospitalization time. The potential role of most known vitamins in preventing, treating COVID-19, and rehabilitating patients was considered. The most promising agents for combating COVID-19 and its consequences might be the following vitamins: vitamin D, ascorbic acid, polyunsaturated fatty acids (PUFAs), and some B complex vitamins. Inorganic elements deserving attention include magnesium and trace elements, such as zinc, selenium, copper, and iron. Some associations were found between micronutrient deficiencies and COVID-19 severity in children, adults, and older people. Patients can obtain the aforementioned micronutrients from natural food sources or as supplements/- drugs in various dosage forms. The reviewed micronutrients might be considered adjunctive treatment strategies for COVID-19 patients.

Concepts and principles for new rapid simple liquid chromatography method for quantification of antioxidants resveratrol, vitamin E, and coenzyme Q10 in capsules with high-performance liquid chromatography with a photo-diode array detector.

Principles and problems in the development of simultaneous liquid chromatography (LC) analytical methods for potent antioxidative molecules resveratrol, tocopherol, and coenzyme Q10 in capsules, have been investigated and systematically compared and summarized. For these purposes, experiments within the full polarity spectrum of LC techniques. were tested and recorded. The whole range of polarities included: Alkyl C18 bonded reversed phase, phenyl, cyanopropyl, diol, and the most polar base silica-filled column matrixes have been used. The summarized results concluded that all mentioned LC techniques could be used for the determination of the mentioned group of the three analytes with different run characteristics and efficiency. These successes could be achieved after careful analyses of molecular physicochemical data of analytes. They are especially organic solubilities. The ultraviolet spectral absorption characteristics of each analyte and the mobile phase constituents for appropriate separation were very important to be known. The ultimate targets were the development method with the isocratic mode of separation yielding symmetrical peak shapes for the best sensitivity and accuracy, with the shortest run time and best reproducibility. From an analytical point of view important for LC, the three analytes have quite distinct characteristics that contribute to successful method development. These features are their organic solvent and water solubility, molecular polarities, and ultraviolet-absorption characteristics, like spectra and absorptivities. All these mentioned parameters were taken into account for solving complications appearing in the development of rapid LC methods for the simultaneous determination of three antioxidant molecules.

LC-MS/MS bioanalytical method for the quantitative analysis of nifedipine, bisoprolol, and captopril in human plasma: Application to pharmacokinetic studies.

In this study, the development and validation of an accurate and highly sensitive LC-MS/MS method were performed for the estimation of nifedipine, bisoprolol and captopril in real human plasma. Liquid-liquid extraction using tert-butyl methyl ether was efficiently applied for extraction of the analytes from plasma samples. The chromatographic separation was carried out using an isocratic elution mode on the X-terra MS C18 column (4.6 × 50 mm, 3.5 µm). The mobile phase consisted of methanol-0.1% formic acid (95:5, v/v) for determination of nifedipine and bisoprolol and acetonitrile-0.1% formic acid (70:30, v/v) for determination of captopril with a flow rate of 0.5 ml/min. Acceptable results regarding the different validation characteristics of the analytes were obtained in accordance with US Food and Drug Administration recommendations for bioanalytical methods. The developed approach was linear over concentration ranges of 0.5-130.0, 50.0-4,500.0 and 0.3-30.0 ng/ml for nifedipine, captopril and bisoprolol, respectively. The method revealed a sufficient lower limit of quantification in the range of 0.3-50.0 ng/ml, as well as high recovery percentages, indicating high bioanalytical applicability. The proposed method was efficiently applied to a pharmacokinetic evaluation of a fixed-dose combination of the analytes in healthy male volunteers.

Chiral Monolithic Silica-Based HPLC Columns for Enantiomeric Separation and Determination: Functionalization of Chiral Selector and Recognition of Selector-Selectand Interaction.

This review draws attention to the use of chiral monolithic silica HPLC columns for the enantiomeric separation and determination of chiral compounds. Properties and advantages of monolithic silica HPLC columns are also highlighted in comparison to conventional particle-packed, fused-core, and sub-2-µm HPLC columns. Nano-LC capillary monolithic silica columns as well as polymeric-based and hybrid-based monolithic columns are also demonstrated to show good enantioresolution abilities. Methods for introducing the chiral selector into the monolithic silica column in the form of mobile phase additive, by encapsulation and surface coating, or by covalent functionalization are described. The application of molecular modeling methods to elucidate the selector-selectand interaction is discussed. An application for enantiomeric impurity determination is also considered.

Chaotropic salts impact in HPLC approaches for simultaneous analysis of hydrophilic and lipophilic drugs.

Simultaneous determination of drugs with different physicochemical properties necessitates thorough research and careful selection of high-performance liquid chromatography conditions. In the present study, various concepts of high-performance liquid chromatography method development for this aim have been discussed. Moreover, the work was motivated by the advantages of utilizing different chaotropic anions as a new promising approach to overcome the limitations of ion-pairing agents commonly used for this purpose. Based on log P values, atorvastatin (log P = 6.36) and lisinopril (log P = -1.22) were chosen as representative examples for lipophilic and hydrophilic drugs, respectively. Several simple, economic, fast, and reliable high-performance liquid chromatography methods were developed for their simultaneous analysis and are presented in a comparative manner, highlighting their advantages and limitations. Peak elution profile showed satisfying retentions and resolution about 3. Photo-diode array calculations were exploited for identifying the molecules by their ultra-violet spectra and peak purity, calculated and presented as rectangular-shaped ratio grams. The linearity check showed excellent results and satisfactory system suitability parameters of both peaks. This confirms the investigation results and conclusions for the influence of the chaotropic salts on N-containing molecules, by increasing their retentivities, and improving peak shapes, even on different quality columns without end-capping and base-deactivating of separation matrixes.

New liquid chromatography assays for simultaneous quantification of antihypertensives atenolol and valsartan in their dosage forms.

Nowadays, various single-pill combinations are used as the best choice in hypertension management. However, these pills made a high challenge to analysts in terms of quality control assays. We have developed three sensitive, selective, fast, simple, green, accurate, precise, and robust isocratic high-performance liquid chromatography methods for simultaneous determination of valsartan and atenolol in dosage forms. To find the appropriate high-performance liquid chromatography conditions for the separation of the examined drugs, various columns, isocratic mobile phase systems were tried, and successful attempts were performed. The used columns proved to be indispensably applicable and gave a shorter analysis time and peak symmetries. This reduction in total run time leads to low solvent consumption and makes all methods more economical. The linearity, accuracy, and precision remained within the acceptable limits. Therefore, all developed methods are suitable for the routine quality control analysis of any pharmaceutical preparation containing the two tested drugs with the proposed chromatographic methods advantages for checking quality during stability studies of their pharmaceutical preparations.

Development of a novel, fast, simple, nonderivative HPLC method with direct UV measurement for quantification of memantine hydrochloride in tablets.

Fast, simple, accurate, and reproducible reverse phase-high-performance liquid chromatography method with direct ultraviolet measurement of memantine hydrochloride in tablets was developed, without any chemical derivatization pretreatment. Three main problems appear during chromatographic analysis of memantine: detection, achieving appropriate column retention, and limited choice of mobile phase components, as a result of memantine molecular structure. Among more than 35 tested columns, the best retention and peak symmetry yielded two C8 and three C18 columns with different characteristics, at a temperature of 30°C, mobile phase composed of 1%, v/v, acetonitrile and 99%, v/v, of 0.05-0.1% phosphoric acid or 2.5-5 mmol phosphate buffer, at flow rate of 1 mL/min and injection volume of 5 µL. The retention time of memantine was between 2.6 and 4 min. Both mobile phase concepts showed perfect linearity, precision, and accuracy. This is the first successful and reproducible direct reverse phase-high-performance liquid chromatography-ultraviolet quantification method for memantine.