Dissolution Profile of Nimesulide from Pharmaceutical Preparations for Oral Use.

Nimesulide belongs to the group of semi-selective COX-2 inhibitors, widely used in solid oral formulations. In the present work the influence of surfactants among other drug excipients, as well as particle size of the active substance and the effects of medium pH on the dissolution rate of nimesulide from solid pharmaceutical forms. For that purpose, four different preparations containing 100 mg nimesulide per tablet and available in the market of Bosnia and Herzegovina (labeled here as A, B, C and D) were studied. The test for the assessment of dissolution profiles of the formulations was performed in surfactant-free dissolution medium pH 7.5. The dissolution profiles were compared by calculating difference (f1), and similarity (f2) factors. The increasing dissolution medium pH value from 7.5 to 7.75 resulted in a significant increase of nimesulide dissolution rate from the examined formulations. Also, the results showed that particle size affects to a great extent the dissolution rate and the best results were achieved with micronized nimesulide. The presence of the surfactants among the other excipients expressed a negligible effect on the dissolution profile.

Design of Novel TRPA1 Agonists Based on Structure of Natural Vasodilator Carvacrol-In Vitro and In Silico Studies.

Considering the escalating global prevalence and the huge therapeutic demand for the treatment of hypertension, there is a persistent need to identify novel target sites for vasodilator action. This study aimed to investigate the role of TRPA1 channels in carvacrol-induced vasodilation and to design novel compounds based on carvacrol structure with improved activities. In an isolated tissue bath experiment, it was shown that 1 µM of the selective TRPA1 antagonist A967079 significantly (p < 0.001) reduced vasodilation induced by 3 mM of carvacrol. A reliable 3D-QSAR model with good statistical parameters was created (R2 = 0.83; Q2 = 0.59 and Rpred2 = 0.84) using 29 TRPA1 agonists. Obtained results from this model were used for the design of novel TRPA1 activators, and to predict their activity against TRPA1. Predicted pEC50 activities of these molecules range between 4.996 to 5.235 compared to experimental pEC50 of 4.77 for carvacrol. Molecular docking studies showed that designed molecules interact with similar amino acid residues of the TRPA1 channel as carvacrol, with eight compounds showing lower binding energies. In conclusion, carvacrol-induced vasodilation is partly mediated by the activation of TRPA1 channels. Combining different in silico approaches pointed out that the molecule D27 (2-[2-(hydroxymethyl)-4-methylphenyl]acetamide) is the best candidate for further synthesis and experimental evaluation in in vitro conditions.

Knowledge and Attitudes regarding Covid-19 Vaccination among Medical and Non-medical Students in Bosnia and Herzegovina.

OBJECTIVE: The aim of this study was to investigate students' knowledge, attitudes and hesitancy regarding COVID-19 vaccination. METHODS: A cross-sectional questionnaire-based survey was conducted among a total of 1282 medical students and 509 non-medical students at four public universities in Bosnia and Herzegovina: Tuzla, Sarajevo, Banja Luka, and Mostar. RESULTS: A significantly higher rate of vaccination was observed in the group of medical students as well as a higher level of knowledge about vaccination in general and vaccines against the COVID-19 disease. Students who received the COVID-19 vaccine had a higher level of knowledge about vaccination in general and COVID-19 vaccines in particular compared to the non-vaccinated students in the medical and non-medical groups, respectively. Furthermore, vaccinated students, regardless of the course they are taking, showed generally stronger positive attitudes compared to non-vaccinated students, regarding the safety and effectiveness of the COVID-19 vaccine. Both groups of students believe that the rapid development of the vaccine is contributing to refusal or hesitancy to receive a vaccine against COVID-19. Social media/networks were the main sources of information about the COVID-19 vaccine. We did not find any contribution of social media to the reduced level of COVID-19 vaccine coverage. CONCLUSION: Education of students about the benefits of the COVID-19 vaccine will lead to its better acceptance as well as the development of more positive attitudes towards vaccination in general, especially having in mind that students are the future population of parents, who will make decisions about vaccinating their children.

In silico Methods for Design of Kinase Inhibitors as Anticancer Drugs.

Rational drug design implies usage of molecular modeling techniques such as pharmacophore modeling, molecular dynamics, virtual screening, and molecular docking to explain the activity of biomolecules, define molecular determinants for interaction with the drug target, and design more efficient drug candidates. Kinases play an essential role in cell function and therefore are extensively studied targets in drug design and discovery. Kinase inhibitors are clinically very important and widely used antineoplastic drugs. In this review, computational methods used in rational drug design of kinase inhibitors are discussed and compared, considering some representative case studies.

3D-QSAR, Virtual Screening, Docking and Design of Dual PI3K/mTOR Inhibitors with Enhanced Antiproliferative Activity.

AIM AND OBJECTIVE: Altered activity of PI3K/mTOR signaling pathway is one of the most common aberrations found in various forms of neoplastic lesions. Dual inhibition of PI3K and mTOR represents a reasonably attractive concept in potential cancer treatment. The main aim of this work was to design novel PI3K/mTOR inhibitors with enhanced antiproliferative activity. MATERIALS AND METHODS: 3D-QSAR pharmacophore modeling studies were performed on two groups comprised of 37 and 48 dual PI3K/mTOR inhibitors. Obtained 3D-pharmacophores were used in design of new dual PI3K/mTOR inhibitors. Based on the in silico ADMET data, structure-based virtual screening and docking studies, the most promising novel candidates were selected. RESULTS: Four reliable PLS models with good statistical parameters (q2 = 0.72, r2 pred = 0.93; q2 = 0.81, r2 pred= 0.88 for 3D-QSAR (mTOR) models and q2 = 0.79, r2pred = 0.93; q2 = 0.79, r2 pred = 0.94 for 3D-QSAR (PI3K) models) were obtained and new highly selective and potent dual PI3K/mTOR inhibitors were designed. Further in silico ADMET profiling of the designed compounds selected the most promising novel PI3K/mTOR inhibitors as drug candidates. Results of the 3D-QSAR studies were confirmed by structure-based virtual screening protocol that identified selected designed compounds as a best fit for PI3K and mTOR receptors. Molecular docking studies on PI3K and mTOR crystal structures revealed the key active site residues involved in binding of PI3K/mTOR ligands. CONCLUSION: After combining the results of 3D-QSAR, ADMET profiling, virtual screening and docking, compounds 56-57 and 56-62 were chosen as the most promising new dual PI3K/mTOR inhibitors.

Synthesis of the vitamin E amino acid esters with an enhanced anticancer activity and in silico screening for new antineoplastic drugs.

Tocopherols and tocotrienols belong to the family of vitamin E (VE) with the well-known antioxidant properties. For certain α-tocopherol and γ-tocotrienol derivatives used as the lead compounds in this study, antitumor activities against various cancer cell types have been reported. In the course of the last decade, structural analogs of VE (esters, ethers and amides) with an enhanced antiproliferative and proapoptotic activity against various cancer cells were synthesized. Within the framework of this study, seven amino acid esters of α-tocopherol (4a-d) and γ-tocotrienol (6a-c) were prepared using the EDC/DMAP reaction conditions and their ability to inhibit proliferation of the MCF-7 and MDA-MB-231 breast cancer cells and the A549 lung cancer cells was evaluated. Compound 6a showed an activity against all three cell lines (IC50: 20.6µM, 28.6µM and 19µM for the MCF-7, MDA-MB-231 and A549 cells, respectively), while compound 4a inhibited proliferation of the MCF-7 (IC50=8.6µM) and A549 cells (IC50=8.6µM). Ester 4d exerted strong antiproliferative activity against the estrogen-unresponsive, multi-drug resistant MDA-MB-231 breast cancer cell line, with IC50 value of 9.2µM. Compared with the strong activity of compounds 4a, 4d and 6a, commercial α-tocopheryl succinate and γ-tocotrienol showed only a limited activity against all three cell lines, with IC50 values >50µM. Investigation of the cell cycle phase distribution and the cell death induction confirmed an apoptosis of the MDA-MB-231 cells treated with 4d, as well as a synergistic effect of 4d with the known anticancer drug doxorubicin. This result suggests a possibility of a combined therapy of breast cancer in order to improve the therapeutic response and to lower the toxicity associated with a high dose of doxorubicin. The stability study of 4d in human plasma showed that ca. 83% initial concentration of this compound remains in plasma in the course of six hours incubation. The ligand based virtual screening of the ChEMBL database identified new compounds with a potential antiproliferative activity on MCF-7 and on multi-drug resistant MDA-MB 231 breast cancer cells.