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A chemometrically based approach was applied to select the most efficient drug adsorbent among the biochars obtained from the novel feedstock, the leaves of the invasive plant (Ailanthus altissima). The representative target adsorbates (atenolol, paracetamol, ketorolac and tetracycline) were selected on the basis of their physicochemical properties to cover a wide chemical space, which is the usual analytical challenge. Their adsorption was investigated using design of experiments as a comprehensive approach to optimise the performance of the adsorption system, rationalise the procedure and overcome common drawbacks. Among the response surface designs, the central composite design was selected as it allows the identification of important experimental factors (solid-to-liquid ratio, pH, ionic strength) and their interactions, and allows the selection of optimal experimental conditions to maximise adsorption performance. The biochars were prepared by pyrolysis at 500 °C and 800 °C (BC-500 and BC-800) and the ZnCl2-activated biochars were prepared at 650 °C and 800 °C (AcBC-650 and AcBC-800). The FTIR spectra revealed that increasing the pyrolysis temperature without activator decreases the intensity of all bands, while activation preserves functional groups, as evidenced by the spectra of AcBC-650 and AcBC-800. High temperatures during activation promoted the development of an efficient surface area, with the maximum observed for AcBC-800 reaching 347 m2 g−1. AcBC-800 was found to be the most efficient adsorbent with removal efficiencies of 34.1, 51.3, 55.9 and 38.2 % for atenolol, paracetamol, ketorolac and tetracycline, respectively. The models describing the relationship between the removal efficiency of AcBC-800 and the experimental factors studied, showed satisfactory predictive ability (predicted R2 > 0.8) and no significant lack-of-fit was observed. The results obtained, including the mathematical models, the properties of the adsorbates and the adsorbents, clearly indicate that the adsorption mechanisms of activated biochars are mainly based on hydrophobic interactions, pore filling and hydrogen bonding.

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.

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.

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.

Chromatograms with overlapping peaks and a baseline rise or upset constitute a great challenge for analysts. Such a case regarding the analysis of bupropion hydrochloride and its 5 impurities in a tablet formulation was used as a model. A baseline correction technique for liquid chromatography coupled with diode array detection is described by using Rstudio. The asymmetry least squares (ALS) algorithm was used as implemented in the “baseline” package, with parameters lambda and p set to 4 and 0.05, respectively. Peak deconvolution and subsequent integration and area quantification were accomplished through Fytik software. Chromatographic data from the validation procedure were utilized to demonstrate the feasibility of the suggested method and whether this correction affects the outcome of the validation study. Finally, a robustness study was carried out in order to shed light on the factors that have a more significant influence on the baseline correction, showing the reliability of this procedure through random changes in its parameters.

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]

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.

Most commonly used analytical technique for determination of active pharmaceutical ingredients and their impurities in quality control throughout all phases of drug research, development and manufacture is definitely reversed-phase high performance liquid chromatography (RP-HPLC). However, pharmaceutical industry professionals are often faced with various challenges in RP mode, which cannot be resolved with common variations in the composition of the mobile phase. These challenges often occur when analyzing compounds that contain basic ionizable groups, possess large differences in polarities and require consumption of high amounts of toxic organic solvents. Among available strategies for addressing the aforementioned issues, the most convenient one includes RP-HPLC mobile phase modifications by an addition of the proper chemical compounds. In that respect, RP-HPLC method can be easily adapted to the needs of the analysis without time-consuming and expensive equipment procurement. In this review the chaotropic chromatography, micellar liquid chromatography, and cyclodextrin modified RP-HPLC systems are presented and discussed in details. Special attention is devoted to the theoretical background, the possibility of retention modeling and applications in various fields of pharmacy, as well as their prospective in further research.

In this study, an AQbD-compliant chaotropic chromatography method for ziprasidone and the determination of its five impurities was developed. The influence of critical method parameters (initial and final methanol fraction in the mobile phase, gradient duration) on the set of selected critical method attributes (t_imp. V, t_imp. V − t_imp. I, S and USP>) was studied by Box–Behnken design. The errors resulting from the calculation of the model coefficients were propagated to the selected responses by Monte Carlo simulations, and their predictive distribution was obtained. The design space was computed (π ≥ 80%), and a working point was selected: initial methanol fraction 38.5%, final methanol fraction 77.5%, and gradient duration 16.25 min. Furthermore, the quantitative robustness of the developed method was tested using the Plackett–Burman design. P_imp II and P_imp V were found to be significantly affected, the first by mobile phase flow rate and the second by gradient duration. Finally, the method was validated, and its reliability for routine quality control in capsules was confirmed.

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]

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.

An alternative to the time-consuming and error-prone pharmacopoeial gas chromatography method for the analysis of fatty acids (FAs) is urgently needed. The objective was therefore to propose a robust liquid chromatography method with charged aerosol detection for the analysis of polysorbate 80 (PS80) and magnesium stearate. FAs with different numbers of carbon atoms in the chain necessitated the use of a gradient method with a Hypersil Gold C18 column and acetonitrile as organic modifier. The risk-based Analytical Quality by Design approach was applied to define the Method Operable Design Region (MODR). Formic acid concentration, initial and final percentages of acetonitrile, gradient elution time, column temperature, and mobile phase flow rate were identified as critical method parameters (CMPs). The initial and final percentages of acetonitrile were fixed while the remaining CMPs were fine-tuned using response surface methodology. Critical method attributes included the baseline separation of adjacent peaks (α-linolenic and myristic acid, and oleic and petroselinic acid) and the retention factor of the last compound eluted, stearic acid. The MODR was calculated by Monte Carlo simulations with a probability equal or greater than 90%. Finally, the column temperature was set at 33 °C, the flow rate was 0.575 mL/min, and acetonitrile linearly increased from 70 to 80% (v/v) within 14.2 min.

The effect of acetonitrile (ACN) on the micellization of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), in aqueous solutions at different temperatures was studied. The critical micellar concentration (CMC) as well as the degree of counter ion dissociation (a) of CTAB in aqueous ACN mixtures (10-20 % v/v) at various temperatures (291.2-298.2 K) were determined by electrical conductivity measurements, while steady-state fluorescence measurements were used to determine several CMCs (for comparison) and a micellar aggregation number (Nagg) as well. At a fixed temperature, both an increase in CMC and a decrease in Nagg were observed for an increase in ACN in the solvent mixture. With a temperature increase, CMC values increased for 10 % (v/v) ACN, while for both 15 % and 20 % (v/v) ACN, CMC values were a minimum at T = 295.2 K with a temperature increase. In addition, some aspects related to the Krafft temperature behavior of CTAB in the examined micellar systems are discussed.

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.

A novel chaotropic chromatography method for the quantitative determination of bupropion and its impurities, following analytical quality-by-design (AQbD) principles, is presented. The analytical target profile (ATP) was defined on the basis of the efficient separation and reliable determination of bupropion and its five impurities in tablets. Preliminary experiments revealed the need for the addition of a gradient elution part. A screening fractional factorial experimental design was employed to select the critical method parameters (CMPs) and a Box–Behnken design (BBD) was utilized to investigate their influence on predefined critical method attributes (CMAs). In order to compute the design space (DS), where CMPs meet predefined acceptance limits with a high level of probability (π ≥ 85%), Monte Carlo simulations were performed. The working point selected from the DS corresponded to the following conditions: 37.5% acetonitrile at the start of the gradient program (up to 70% at the end of the gradient program), 45 mM of potassium hexafluorophosphate in the water phase, and the start of the linear gradient step in the gradient program at 10 min. The method was validated according to ICH guidelines and applied to the analysis of Wellbutrin® tablets containing bupropion hydrochloride.

In this research, a UHPLC–MS/MS method was developed and validated for the determination of zonisamide in dried plasma spots (DPS) and dried blood spots (DBS). Detection of zonisamide and internal standard, 1-(2,3-dichlorphenyl)piperazine, was carried out in ESI+ mode by monitoring two MRM transitions per analyte. Total run time, less than 2.5 min, was achieved using Acquity UPLC BEH Amide (2.1 × 100 mm, 1.7 µm particle size) column with mobile phase comprising acetonitrile–water (85:15%, v/v) with 0.075% formic acid. The flow rate was 0.225 mL/min, the column temperature was 30 °C and the injection volume was 3 µL. Desolvation temperature, desolvation gas flow rate, ion source temperature and cone gas flow rate were set by the IntelliStart software tool in combination with tuning. All of the Guthrie cards were scanned, and DPS/DBS areas were determined by the image processing tool. The influence of hematocrit values (20–60%) on accuracy and precision was evaluated to determine the range within which method for DBSs is free from Hct or dependency is within acceptable limits. The validated method was applied to the determination of zonisamide levels in DPS and DBS samples obtained from patients confirming its suitability for clinical application. Finally, the distribution of zonisamide into the red blood cells was estimated by correlating its DPS and DBS levels.

Microencapsulation of bioactive substances is a common strategy for their protection and release rate control. The use of chitosan (Ch) is particularly promising due to its abundance, biocompatibility, and interaction with anionic surfactants to form complexes of different characteristics with relevance for use in microcapsule wall design. In this study, Ch/sodium dodecyl sulfate (SDS) microcapsules, without and with cross-linking agent (formaldehyde (FA) or glutaraldehyde (GA)), were obtained by the spray drying of vitamin E loaded oil-in-water emulsion. All of the microcapsules had good stability during the drying process. Depending on the composition, their product yield, moisture content, and encapsulation efficiency varied between 11–34%, 1.14–1.62%, and 94–126%, respectively. SEM and FTIR analysis results indicate that SDS as well as cross-linkers significantly affected the microcapsule wall properties. The profiles of in vitro vitamin E release from the investigated microcapsules fit with the Korsmeyer-Peppas model (r2 > 0.9). The chemical structure of the anionic surfactant was found to have a significant effect on the vitamin E release mechanism. Ch/SDS coacervates may build a microcapsule wall without toxic crosslinkers. This enabled the combined diffusion/swelling based release mechanism of the encapsulated lipophilic substance, which can be considered favorable for utilization in food and pharmaceutical products.

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]

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.