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Recently, concern about the environmental impact of drug analysis methods has increased significantly. Reversed-phase high-performance liquid chromatography (RP-HPLC), the predominant technique in drug analysis, relies heavily on organic solvents such as acetonitrile, which is known for its chromatographic efficiency, but also for its toxicity and flammability. To address these concerns, it is essential to minimize the use of toxic organic solvents. The aim of this study is to explore greener RP-HPLC modifications and evaluate their applicability in the pharmaceutical industry. Methods were developed for the separation of dronedarone hydrochloride and its degradation products based on experimental design, including micellar liquid chromatography (MLC), b-cyclodextrin (CD) modified RP-HPLC and ultra-high performance liquid chromatography (UHPLC). The eco-friendliness of these methods was assessed using the analytical eco-scale score, green analytical procedure index (GAPI) and analytical greenness (AGREE). AGREE appears to be the most suitable, as it revealed the greatest differences between the compared methods, as well as insights into critical aspects of the methods. UHPLC and b-CD modified RP-HPLC have been shown to be superior to MLC, and both methods can be a good choice, depending on whether the ease of implementation or energy efficiency is considered to be a more important criterion.

In recent years, Deep Eutectic Solvents (DESs) have attracted increasing attention in various scientific disciplines. Their unique properties, such as low toxicity, biodegradability, low cost and versatility, have made them an attractive alternative to conventional organic solvents. In pharmaceutical analysis, where the demand for environmentally friendly methods is growing, questions regarding whether DESs can replace organic solvents as "green solvents" have arisen. This paper explores the potential applications of DESs in drug analysis, and highlights the benefits and challenges they bring. Examples of the use of DESs in chromatographic techniques and in the extraction of drugs from various samples are presented. Additionally, research on the stability and toxicity of DESs in analytical applications is discussed. Based on the available data, it could be concluded that DESs have the potential to become an important component of analytical methods in pharmaceutical analysis and provide environmentally sustainable and efficient alternatives to conventional organic solvents. However, further research is needed to better understand their properties and optimize their application in drug analysis.

Polyelectrolyte complexes (PECs) are attractive carriers with recognized potential to enhance oral delivery of poorly soluble high-dosed low-molecular-weight drugs. The formulation of solid oral dosage forms requires the drying of PECs, which may affect their physicochemical and biopharmaceutical properties. The aim of this study was to investigate the effect of spraydrying on the properties of ibuprofen-loaded chitosan/xanthan gum PECs and to assess the drug release kinetics from such PECs filled into hard capsules in comparison with corresponding PECs which are dried under ambient conditions. The yield, ibuprofen content, entrapment efficiency, and residual moisture content of spray-dried PECs were lower than those of ambient-dried PECs. Better flowability of spray-dried PECs was attributed to the almost spherical particle shape, shown by scanning electron microscopy. DSC and PXRD analysis confirmed the amorphization of ibuprofen during spray-drying. All the investigated PECs, obtained by drying under ambient conditions as well as by spray-drying, had high rehydration capacity both in 0.1 M hydrochloric acid (pH 1.2) and phosphate buffer pH 7.4. In vitro ibuprofen release from dried PECs was controlled during 12 h with the release of approximately 30% of entrapped ibuprofen. Spray-dried PECs provided better control of ibuprofen diffusion from the carrier compared to the ambientdried ones.

In this research, Analytical Quality by Design (AQbD) methodology was used to develop the HILIC-PDA-CAD method for the determination of magnesium, pyridoxine and thiamine content in a dietary supplement. Experiments were conducted on the Dionex Ulitimate 3000 HPLC system with PDA and CAD detectors. Separations were performed on the ZIC-HILIC PEEK column (100 × 4.6 mm, 5 mm) with a mixture of acetonitrile, acetone and ammonium acetate/ammonium formate aqueous solution (48:12:40, v/v/v) as the mobile phase. The detection was performed at 220 nm. The optimal settings of CAD were defined with the one-factor-at-a-time approach: evaporation temperature 50°C, filter constant 10 s, pressure gas 60 psi. The influence of qualitative (salt type) and quantitative factors (pH and salt concentration) on the magnesium retention factor, k Mg and the selectivity factor between pyridoxine and chloride anion, a B6/Cl-, was tested using the I-optimal design. The design space was defined by Monte Carlo simulations and model coefficients' errors were propagated with the aim of identifying the conditions that meet the following criteria: k Mg 3.5, with the probability p=95%. From the derived 2D-Design Space graph, 95 mM of ammonium formate pH 4.4 was selected as the optimal composition of the aqueous phase. The method was validated and its reliability in routine application was confirmed.

Effective method development together with method`s eco-friendly character are gaining importance in drug analyses nowadays. One of the strategies often applied to improve the efficacy of separation methods, especially in the case of basic ionizable analytes is adding chaotropic salts into the mobile phases. Moreover, the development of the green liquid chromatography method could also be achieved with certain mobile phase additives such as cyclodextrin (CD). The study aims to investigate whether adding chaotropic agents could improve the complexation process by disrupting the analytes' water solvation shell. The model mixture consisted of risperidone, olanzapine, and their related impurities. Method development was aided with experimental design methodology, while optimal separation conditions were selected using Derringer's desirability function. Mathematical models obtained for each of the examined responses enabled the explanation of the single and simultaneous influence of b-CD concentration, chaotropic agents type, and content, as well as the content of acetonitrile in the mobile phase. Retention factors appeared to be the most influenced by acetonitrile content in the mobile phase. The type of chaotropic agent as well as its concentration lead to retention prolongation, but if acetonitrile content in the mobile phase is high, the effect of chaotropic agent becomes negligible. Interaction between analyte and b-CD are relatively weak in comparison to the interaction of analyte form with either chaotropic agent or acetonitrile. Interaction leading to complexation are outperformed by other analyte related interactions in this complicated system, so complexation based retention reduction is not fully exposed. However, increasing b-CD concentration shows a positive effect on the resolution between critical peak pairs. Optimal separation conditions were selected based on 3D plots of Derringer's desirability function. For olanzapine and its impurity, they included the following: acetonitrile content 16% (v/v), trifluoroacetic acid as a chaotropic agent with 0.95% (v/v) content, and 9 mM b-CD concentration. Further, optimal separation conditions for risperidone and its impurity were 25% (v/v) acetonitrile content in the mobile phase, trifluoroacetic acid as chaotrope agent with 0.27% (v/v) content and 5mM b-CD concentration.

Conductivity of two micellar systems was measured in order to determine critical micelle concentration (CMC) of cetyltrimethylammonium bromide (CTAB). Those systems were: CTin water and CTin binary mixture acetonitrile (ACN)-water. Conductivity (κ)-concentration (c) data were treated by four different methods: conventional method, differential methods (first and second derivative) and method of integration (methods A-D, respectively). As CTin water micellar system shows a sharp transition between premicellar and postmicellar part of the κ/c curve, any of the applied methods gives reliable CMC values and there is no statistically significant difference between them. However, for CTin ACN-water mixture micellar system the integration method for CMC determination is recommended due to a weak curvature of κ/c plot.

Vascular stents are general medical devices of class III or IIb, which are placed along the walls of the constricted coronary and peripheral blood vessels thus keeping them viable. According to the mechanism of expansion, stents may be balloon-expandable or self-expanding. Depending on the geometry they can be classified into: coil stents, open-cell modular stents and multi-cell closed cell stents. The most important characteristic of vascular stents is their flexibility, but a number of additional requirements must also be met: high radial strength, low elastic deformation, small diameter, the possibility of monitoring through the bloodstream, minimum subsequent shortening, minimum elastic longitudinal deformation, and the optimal retention at target site. Materials for production of stents must be biologically inert, visible by radiological techniques, biocompatible, corrosion-resistant and resistant to stress due to blood flow. The most significant adverse event after stent implantation is the occurrence of restenosis, which is most efficiently overcome by the application of drug releasing stents. These stents are composed of three parts: stent platform, drug carrier and a drug that inhibits neointimal hyperplasia - paclitaxel and limuses (sirolimus, everolimus, zotarolimus, tacrolimus, pimecrolimus, etc.). In recent years, stents with surfaces coated with substances that accelerate endothelialisation and thus reduce thrombosis have been developed. The latest approach is represented by a stent with the lumen coated with CD34 antibody, and the outer side coated with sirolimus. By using these devices a double effect is achieved: acceleration of endothelialisation and inhibition of neointimal hyperplasia.

For the simultaneous analysis of multicomponent mixture containing pseudoephedrine, paracetamole and ascorbic acid two RP-HPLC methods were developed. Separation were performed on Hewlett Packard 1100 system which consisted of HP 1100 binary pump, HP 1100 UV/VIS detector and HP ChemStation for the automatic data evaluation. Methods were developed, e. g. chromatographic conditiond settled, methods submited to method validation and then applied for the determination of content of multicomponent powder.The best separation was achived on Platinium Alltech Amino 150 x 4.6 mm, 5 mm particle size column, at 30°C. Injection volume was 20mL. Mobile phase in mehtod I was a mixture of methanol-water (30:70 V/V), pH 2.5, and in mehtod II was a mixture methanol-water (60:40 V/V), pH 2.9. pH of the mobile phases were adjusted with 85% ortophosphoric acid. Detection was performed at 214 nm in mehtod I and at 257 nm in method II. Flow rate was 1 mLmin-1. Developed methods were validated. Obtained results showed that both methods are suitable for routine analysis of pharmaceutical dosage forms which contain pseudoephedrine, paracetamole and ascorbic acid.

In this paper the experimental conditions for optimal reversed-phase liquid chromatographic (RP-HPLC) determination of sulfamethoxazole, trimethoprim and preservatives, as well as degradation products of sulfamethoxazole and trimethoprim in syrup were defined. The determination of active compounds and preservatives was carried out on Zorbax Eclipse XDB-C18, 150 mm × 4.6 mm, 5 μm particle size column, mobile phase flow rate was 1.5 mL min-1, and detection at 235 nm for the active compounds and 254 nm for preservatives. Mobile phase A consisted of 150 mL of acetonitrile, 850 mL of water and 1 mL of triethanolamine (pH 5.90 adjusted with diluted acetic acid), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. For the determination of degradation products Zorbax Eclipse Plus C18, 100 mm x 4.6 mm, 3.5 μm particle size column was used, the mobile phase flow rate was 0.5 mL min-1 and detection at 210 nm for 3,4,5-trimethoxybenzoic acid and 254 nm for sulfanilic acid and sulfanilamide. Mobile phase A was 50 mM potassium dihydrogenphosphate (pH 5.60 adjusted with a 0.5 mol L-1 potassium hydroxide), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. Through the validation of the developed methods their efficiency and reliability is confirmed and consequently the adequacy for the routine control.

Modern trends in drug quality control are moving toward incorporating quality into the method during its development. That course is in accordance with Quality by Design (QbD) concept defined by ICH Q 8 (R2) guideline. This implies that the method development begins by defining the method goals and collecting the relevant data, i.e. analyzing the properties of a given active pharmaceutical ingredient and evaluating the optimal experimental conditions. It is followed by a risk assessment defined by systematic robustness testing with the application of experimental design, while the final confirmation of the method reliability is done through the complete validation tests. In this paper, development of Karl Fischer titration for water determination in active pharmaceutical substance clindamycin phosphate is presented. Karl Fischer titration (KFT) is a widely used method in the pharmaceutical industry for determination of water content. For the analyzed substance, the European Pharmacopoeia suggests a relatively large amount of samples for the determination of water, so the objective of this study is to confirm the applicability of the developed method for the determination of water in small amount of samples applying QbD approach. According to QbD rules, detail development of coulometric Karl Fischer titration for water determination in clindamycin phosphate was done. For robustness testing fractional factorial design 24-1 was successful applied and confirmed that method was robust. Robustness was evaluated using statistical and graphical methods. Also, design space was defined so the region, in which factors could be changed without significant changes in water content, was defined. At the end, other validation parameters were determined and it was proved that analytical test system was capable of providing useful and valid analytical data.

In this paper, a second-derivative spectrophotometric method of assaying Septalen ® pellets (Krka, Novo Mesto, Slovenia), which contain lidocaine 1 mg, and cetrimoniumbromide 2mg, is described. Lidocaine, 2-(diethylamino)-N-(2,6-dimethyl- phenyl)-acetamide, is a local anesthetic with pronounced antiarhythmic and anticonvulsant properties. Cetrimoniumbromide, N,N,N-trimethyl-l-hexadecanaminium bromide, is a topical antiseptic and cleansing agent. Lidocaine was determined at 250 nm using the "zero crossing" technique because the signals of centrimonium bromide and the colour ingredient are zero at this wavelength. Cetrimonium bromide was determined by correction of the peak amplitude at 215 nm according to lidocaine. In choosing the optimal magnitudes for the simultaneous determination of both drugs, the following criteria were considered: (1) the linearity of the calibration graphs as given by the correlation coefficients, (2) the intercept, (3) the sensitivity as given by the regression coefficient, (4) the degree of interference in the derivative measurement by the presence of the other compound, as given by the relative percent error and by the relative recovery, and (5) the reproducibility, as given by the coefficient of variation, calculated by recording the second-derivative spectra.

Dried blood spots (DBSs) are formed by collecting a small sample of blood on specialized filter paper and allowing it to dry naturally. Various domains of life sciences and drug research extensively use DBSs as a sampling technique. The "Hematocrit (Ht) effect" affects assay bias, and several strategies have been put forth to deal with it, including the correction of quantified concentrations using an appropriate correction factor. The approach was previously applied, following the utilization of an image processing algorithm developed in Matlab® to derive a reliable equation correlating DBS areas to Ht% values. The present work looks more closely at the application of image analysis to the evaluation of Ht in DBS samples. Utilizing image analysis software, DBS samples with known Ht values were processed. Preparation of cards has followed a previously developed protocol for the appropriate formation of uniform area DBSs, irrespective of Ht. The resulting areas showed close resemblance to the respective theoretical areas calculated by applying the correlation equation. Following that, the equation was utilized to determine the Ht values for each sample, and a comprehensive comparison of measured versus calculated Ht was carried out using various statistical approaches for method comparison. The results demonstrated a strong correlation, suggesting the method's viability in estimating Ht for unknown DBS samples. [ABSTRACT FROM AUTHOR]

The development of efficient adsorbents for sustainable adsorption processes is required in environmental studies. Here, we propose using carbonized Ailanthus altissima leaves as a novel adsorbent, derived from invasive species that threaten biodiversity. Biochar was prepared by pyrolysis at 500 °C, activated with ZnCl2 and tested for the target adsorbates—active pharmaceutical ingredients (APIs). A range of characterization techniques were employed—FTIR, SEM, XPS and Raman spectroscopy—and the adsorption of representative APIs was analyzed. The adsorption kinetics revealed that the adsorbent reached equilibrium within a 3 h period. The adsorption capacities for the selected model substances ranged from 59 mg g−1 for atenolol to 112 mg g−1 for paracetamol, while the highest values were recorded for ketorolac and tetracycline at over 130 mg g−1. The excellent retention is ascribed to the developed surface area, the availability of oxygen surface functional groups and the aromatization of the biochar. The proposed biochar, which is obtained in a sustainable process, proves to be a highly efficient adsorbent for selected pharmaceuticals. [ABSTRACT FROM AUTHOR]

Digital transformation in education and relevant calls for action are recognised global priorities aimed to support education and training in the digital age. The experiences from the emergency remote teaching during the COVID‐19 pandemic and recent research findings reveal relevant advantages, challenges, as well as different students and teaching staff perspectives which should be carefully considered and integrated into institutional strategies and policies to improve and enrich students' learning experience. The present study aimed to explore health sciences students' perspectives on online teaching and learning (T&L) in four domains—Satisfaction, Motivation, Interaction and Challenges, and to identify the preferred T&L models or tools. A total of 1,041 responses were collected, including 476 dental medicine (45.7%), 399 pharmacy (38.3%), and 166 medical students (15.9%). Overall Satisfaction was quite high (4.0 ± 1.2; out of 5), followed by satisfactory Interaction (3.4 ± 1.4), whereas Motivation was quite low on average (3.0 ± 1.5). Challenges in online T&L were not markedly expressed (3.0 ± 1.6). The majority of students (46.6%) opted for the blended model as the preferred T&L model. Moodle lessons were perceived as the most useful online T&L tool (45.5% of students), followed by video materials (32.2%). Other T&L tools which require more active student's role, such as short test/quiz, and group or team assignment were declared as less favourable. The findings from the current study may contribute to raising the awareness of academic staff and higher institutions management about the student attitudes and needs related to online T&L and inform institutional planning, decision‐making and policy development. [ABSTRACT FROM AUTHOR]

This paper explores the distribution pattern of SAR1g within the adult male head during utilization of hands-free operation of contemporary mobile phones as a source of electromagnetic radiation. The research assesses the optimal positioning of the mobile phone by examining three distinct orientations to determine the minimal SAR1g distribution compared to the conventional talking position when hands-free feature is not utilized. The analysis encompasses GSM bands operating at 900 MHz and 1800 MHz, depending on the alignment between the mobile phone and the head. [ABSTRACT FROM AUTHOR]