Search

Corticosteroids are anti-inflammatory and immunosuppressant drugs. Topical corticosteroids formulations (ointments, creams, gels) are used in the treatment of different types of dermatitis and urticaria. Considering their therapeutic and whitening effects, they are frequently used for counterfeiting of cosmetic products. Corticosteroids can cause different local and systemic side effects. HPLC method is often chosen for their analysis, because it is selective, sensitive, precise, simple and fast.The aim of this study was optimization and validation of RP-HPLC method with UV detection for determination of trace levels of corticosteroids in ambiphilic creams. This method is used for qualitative and quantitative analysis of evaluated corticosteroids.Mometasone furoate, hydrocortisone acetate, fluocinonide, fluocinolone acetonide, betamethasone, betamethasone dipropionate and triamcinolone acetonide were evaluated. Separation was performed on Inertsil® ODS-3V 250 × 4.6 mm, 5 μm chromatographic column. Mobile phase was mixture of acetonitrile and water 50:50 (v/v) with gradient elution and flow rate 1 mL min−1. Column temperature was held on 40 °C and UV detection was performed at 240 nm.Selectivity, linearity, accuracy, precision and limit of quantification (LOQ) were evaluated. Method is selective because ambiphilic cream base peaks and corticosteroids peaks were not overlapping. Linearity was confirmed since correlation coefficient was 1 for all compounds. Accuracy and precision were evaluated for hydrocortisone acetate and betamethasone dipropionate. Determined Recovery values were in range of 70–130%. Both RSD values (21.46% and 9.59%) were lower than 30%. Method is highly sensitive since LOQ concentrations were in ng mL−1 range.All evaluated parameters of validation were in accordance with regulatory requirements. Validated RP-HPLC method can be used for qualitative and quantitative analysis of selected corticosteroids in ambiphilic creams.

The serotonin receptor ligands and their related compounds are used for the treatment of central nervous system (CNS)-related disorders. The retention profile of six serotonin receptor ligands such as aripiprazole, ziprasidone, risperidone, olanzapine, mianserin, and quetiapine was investigated on two stationary phases that differ in polarities (C8 alkyl and pentafluorophenylpropyl (PFP)). The design of experiments (DoE) methodology was used to define the retention mechanism and to produce acceptable separation results. The chromatographic conditions that provide the best selectivity characteristics are considered for the separation of structurally related oxidative impurities. The selected conditions (C8 stationary phase, 40% acetonitrile, 20mM ammonium acetate, 25 ℃) showed better sensitivity and improved selectivity in the separation of aripiprazole, ziprasidone, and their oxidative degradants compared to the already developed high-performance liquid chromatography methods. The selected method was validated for the determination of aripiprazole in pharmaceutical forms and was found to be selective, sensitive, precise, accurate, and robust. It can be used as a basis for rapid chromatographic profiling of serotonin receptor ligands and their related impurities.

Medullary thyroid carcinoma is a form of neuroendocrine tumor that arises from parafollicular C cells which produce calcitonin. In addition to calcitonin, these cells produce smaller amounts of other peptides, including carcinoembryonic antigen (CEA), which is used as a nonspecific tumor marker in the follow-up of patients with this tumor. MTC is a rare thyroid tumor and occurs three times more often in women than in men. It can occur in two forms, sporadic (80%) and familial form (20%). The familial form can occur alone or in association with other endocrine tumors within MEN 2A and MEN 2B syndromes. The sporadic form most often occurs in the fifth and sixth decades of life. The familial form is inherited autosomally dominantly, most often based on a mutation in the RET protooncogene located on chromosome 10. C-cell hyperplasia is considered to be a premalignant lesion, which precedes medullary carcinoma. Medullary carcinoma metastasizes very early. We presented a patient with a sporadic form of MTC which appeared at a typical age. Initial values of both baseline and stimulated calcitonin were not in the range for suspected MCT, but due to persistent increases in calcitonin, with elevated baseline (63 pg / mL) and higher stimulated calcitonin (96 pg / mL), the patient was referred for surgical treatment. Due to the strong correlation of calcitonin values with tumor size, the initial calcitonin values were expected to be low because the tumor was 3 mm in size. The histopathological diagnosis was C-cell hyperplasia. However, due to the fact that nodular C-cell hyperplasia is histopathologically difficult to distinguish from medullary microcarcinoma, based on the persistent increase in calcitonin levels, the patient was likely to already have metastatic disease at the time of thyroidectomy. Definitive diagnosis was made by liver biopsy. Therapy with tyrosine kinase inhibitors was introduced, and calcitonin levels strarted to decrea, but there is an increase in carcinoembryonic antigen, which is a poor prognostic parameter.

Thyroid nodules (TN) are present in about half of the population. About 5% of all nodules are malignant. Image-guided methods for the treatment of TN are becoming a significant alternative to surgery. Percutaneous ethanol ablation (PEA) is effective in the treatment of thyroid cysts, and neck lymph node metastases. Percutaneous laser ablation (PLA) significantly reduces the size of the nodules and improves subjective symptoms. The adverse effects of PEA are rare, transitory, and mild. Radiofrequency ablation (RFA) is effective for nodules of all sizes and compositions. The major complications of RFA are rare and transient. Microwave ablation is also effective in the treatment of thyroid nodules with rare major complications. High-intensity focused ultrasound (HIFU) is a transcutaneous method. It is effective in the treatment of thyroid nodules, and complications are rare. Graves' hyperthyroidism was also treated with HIFU. As thermal ablation (TA ) methods are becoming more popular in 2020, the European Thyroid Association published clinical practice guidelines for the use of image-guided ablation in benign thyroid nodules. A meta-analysis showed that low-risk papillary thyroid microcarcinoma recurrences after TA treatment are rare, as are complications. As the TA methods are acceptable for the treatment of the low-risk papillary thyroid carcinoma European Thyroid Association and Cardiovascular and Interventional Radiological Society of Europe issued clinical practice guidelines for the use of minimally invasive treatments in malignant thyroid lesions. Image-guided treatments for thyroid nodules and cancer are here to stay. Their use will expand and become part of routine clinical practice.

Background: Multiple sclerosis (MS) is characterized by inflammation, demyelination and axonal degeneration. Oxidative stress (OS) plays a significant role in the pathogenesis of the disease. The aim of the study was to examine the association between OS and smoking on the MS development. Methods: The study included 175 patients with relapsing- remitting multiple sclerosis (RRMS) (76 males, 99 females) and 254 healthy subjects (81 males and 173 females). Oxidative stress biomarkers in serum, Total Antioxidant Status (TAS) and Total Oxidative Status (TOS) were determined spectrophotometrically. Oxidative Stress Index (OSI) was calculated as the ratio of TOS and TAS. Urinary 8-oxo- 7,8-dihydro-2’-deoxyguanosine were determined by HPLC-MS/MS and expressed as 8-oxodG/creatinine. Results: In females with RRMS were higher TOS, OSI and 8-oxodG/creatinine than in females in control group. The group of males with RRMS had lower level of TAS than the males in control group. Higher levels of 8-oxodG/creatinine was obtained in active, passive and former smokers with RRMS than in control group with the same exposition to tobacco smoke. Independent predictors of MS are passive smoking, increased OSI and increased levels of urinary 8-oxodG/creatinine. Conclusions: Our results demonstrate that the OS parameters should be included in the assessment of the risk for MS development. Due to the more sensitivity to oxidative stress, females may be at higher risk of MS development. This data indicates the importance of introducing the antioxidant therapy as a complementary treatment in patients with RRMS. Uvod: Multipla skleroza (MS) se karakteriše upalom, demijelinizacijom i degeneracijom aksona. Oksidativni stres (OS) igra značajnu ulogu u patogenezi bolesti. Cilj studije je bio da se ispita povezanost OS i pušenja na razvoj MS. Metode: Studija je obuhvatila 175 pacijenata sa relapsnoremitentnom multiplom sklerozom (RRMS) (76 muškaraca, 99 žena) i 254 zdrava ispitanika (81 muškarac i 173 žene). Biomarkeri oksidativnog stresa u serumu, ukupni antioksidativni status (TAS) i ukupni oksidativni status (TOS) su određeni spektrofotometrijski. Indeks oksidativnog stresa (OSI) je izračunat kao odnos TOS i TAS. Urinarni 8-okso7,8-dihidro-2'-deoksiguanozin je određen HPLC-MS/MS i izražen kao 8-oksoG/kreatinin. Rezultati: Kod žena sa RRMS bili su viši TOS, OSI i 8okodG/kreatinin nego kod žena u kontrolnoj grupi. Grupa muškaraca sa RRMS imala je niži nivo TAS od muškaraca u kontrolnoj grupi. Veći nivoi 8-okodG/kreatinina su dobijeni kod aktivnih, pasivnih i bivših pušača sa RRMS nego u kontrolnoj grupi sa istom izloženošću duvanskom dimu. Nezavisni prediktori MS su pasivno pušenje, povećan OSI i povećani nivoi 8-okodG/kreatinina u urinu. Zaključak: Naši rezultati pokazuju da parametre OS treba uključiti u procenu rizika za razvoj MS. Zbog veće osetljivosti na oksidativni stres, žene mogu biti izložene većem riziku od razvoja MS. Ovi podaci ukazuju na značaj uvođenja antioksidativne terapije kao komplementarnog lečenja kod pacijenata sa RRMS.

U Završnom radu je prikazana primena 3D skeniranja pri obradi mermera. 3D skeniranje se u većini slučajeva primenjuje za izradu 3D modela koji služe za naknadnu obradu mermera 3D obradom primenom CNC mašina. Navedeni postupak obrade predstavlja trenutno najsavremeniji, veoma precizan i kompleksan način obrade kojim se mogu postići različiti oblici mermernih objekata. 3D skeniranje se danas dosta primenjuje osim u industriji i pri konzervatorsko-restauratorskim radovima, tokom izrade replika ili kalupa poznatih skulptura i dr. Preciznost 3D obrade zavisi od preciznosti i kvaliteta 3D skeniranja, koji treba da omogući izradu određenih 3D modela kao ulaznih parametara dalje 3D obrade.

Ziprasidone is the second generation antipsychotic drug with unique multipotent G-protein-coupled (GPCR) receptor binding profile. Since ziprasidone is a highly lipophilic and unstable compound, development of efficient method for a concurrent assay of ziprasidone and its main impurities was a very challenging task. The UHPLC-MS/MS method that we developed for simultaneous determination of ziprasidone and its main impurities (BITP, Chloroethyl-chloroindolinone, Zip-oxide, Zip-dimer, and Zip-BIT) was compared with some other related HPLC-UV methods of our own and other authorship. An increase of the mobile phase pH value from 2.5 to 4.7 units in the examined analytical methods influenced elution order of the investigated compounds. It was found out that the UHPLC-MS/MS method is more selective and sensitive than the earlier developed HPLC-UV method. Similar to our earlier HPLC-UV method, the UHPLC-MS/MS method is linear with a correlation coefficient (r) above 0.99 for all the analysed compounds, but with a negligibly lower precision and accuracy. Finally, with shorter analysis time, smaller column size and reduction of solvent consumption, UHPLC-MS/MS is assumed as a greener method than HPLC-UV for the ziprasidone purity assay. After transfer of the UHPLC-MS/MS method to the UHPLC-DAD system, suitability of the UHPLC-DAD method for routine control of ziprasidone and its main impurities is examined and confirmed based on the retained good selectivity, resolution and short analysis time.

Simultaneous quantification of multiple psychiatric drugs is important for the therapeutic drug monitoring of psychiatric patients. In addition, it would be highly advantageous if the method could be simple, straightforward, and not time-consuming. A 200 µl plasma sample was deproteinized, drugs were separated by a ZORBAX Eclipse XDB-Phenyl column with the mobile phase composed of acetonitrile and 0.1 % formic acid in water (60:40, v/v), and recorded in the MRM mode by using a positive electrospray source with tandem mass spectrometry detection. The dynamic range was 2–256 ng/ml for all the analyzed drugs, except escitalopram (8-256 ng/ml). Quality control samples were prepared in quintuplicates in three relevant concentrations for each drug. Coefficients of determination (R2 ) were higher than 0.99, while the relative difference between nominal and measured concentrations (RE) and CV were lower than 15% for all targets. High performance liquid chromatography coupled with the mass detector (HPLC-MS/MS) method for simultaneous determination of sertraline, escitalopram, risperidone 366 and paliperidone in human plasma was validated with respect to selectivity, linearity, accuracy, precision, matrix effect and stability. This method has significant advantages in terms of low sample volume (200 µl), short preparation time (3 hours) and short runtime per sample (4 minutes). Simultana kvantifikacija većeg broja psihijatrijskih lekova je važna za terapijsko praćenje psihijatrijskih pacijenata. Takođe , od značaja iz praktičnih ra zloga bi bilo da metoda bude jednostavna, laka za izvođenje i da ne zahteva puno vremena. Uz orak plazme (200 μl) je deproteinizovan i izvršeno je h romatografsko razdvajanje lekova na ZORBAX Eclipse XDB- Phenyl koloni sa mobilnom fazom sačinjenom od acetonitrila i vo denog rastvora 0,1% mravlje kiseline ( 60:40, v/v). Maseni spektri snimani su u MRM modu korišćenjem i zvora sa elektrosprej pozitivnom jonizacijom i tandemske masene detekcij e. Ispitivani opseg koncentracija bio je 2–256 ng/ml za sve analizirane lekove, osim za escitalop ram, gde je bio 8-256 ng/ml. Kontrolni uzorci su pripremani u kvintuplikatu u tri relevantne koncentracije za svaki lek. Determinacioni koeficijenti (R 2 ) bili su veći od 0,99, dok su relativna razlika između nominal nih i merenih koncentracija (RV) i koeficijent varijacije (CV) bili manji od 15% za sve analite. Metoda tečne hromatografije visoki h performansi uparena sa tand em masenim detektorom (HPLC-MS/MS) je validirana u pogledu selektivnosti, linearnosti , tačnosti, preciznosti, efekata matriksa i stabilnosti za simultano određivanje sertralina, escitaloprama, risperidona i paliperidona u humanoj plazmi. Metoda zahteva malu zapreminu uz orka (200 μl), kratke pripreme uzorka (3 sata) i kratko vreme tr ajanja pojedinačnog merenja (4 minuta).

Background: Since the beginning of the HIV/AIDS epidemic, 75 million people have been infected with the HIV and about 32 million people have died of AIDS. Investigation of the molecular mechanisms critical to the HIV replication cycle led to the identification of potential drug targets for AIDS therapy. One of the most important discoveries is HIV-1 protease, an enzyme that plays an essential role in the replication cycle of HIV. Objective: The aim of the present study is to synthesize and investigate anti-HIV-1 protease activity of some chalcone derivatives with the hope of discovering new lead structure devoid drug resistance. Methods: 20 structurally similar chalcone derivatives were synthesized and their physico-chemical characterization was performed. Binding of chalcones to HIV-1 protease was investigated by fluorimetric assay. Molecular docking studies were conducted to understand the interactions. Results: The obtained results revealed that all compounds showed anti-HIV-1 protease activity. Compound C1 showed the highest inhibitory activity with an IC50 value of 0.001 μM, which is comparable with commercial product Darunavir. Conclusion: It is difficult to provide general principles of inhibitor design. Structural properties of the compounds are not the only consideration; ease of chemical synthesis, low molecular weight, bioavailability, and stability are also of crucial importance. Compared to commercial products the main advantage of compound C1 is the ease of chemical synthesis and low molecular weight. Furthermore, compound C1 has a structure that is different to peptidomimetics, which could contribute to its stability and bioavailability.

Gentamicin sulfate is a potent broad spectrum aminoglycoside antibiotic which is used against Gram-positive and Gram-negative bacteria. A simple, isocratic HPLC method for separation, identification and determination of gentamicin and parabens (methylparaben and propylparaben) was developed and validated. To our knowledge there is no report about simultaneous determination of those three analytes in pharmaceutical products. The optimum chromatographic conditions were achieved on CN column with a mobile phase consisting of 0.15% triethylamine in 10 mM KH2PO4 aqueous solution (final pH 3.0 adjusted with H3PO4) and methanol in the ratio 70:30 (v/v), providing selective quantification of analytes within 5 min. The method was successfully validated according to ICH guidelines acceptance criteria in terms of selectivity, linearity, accuracy, precision and robustness. The linearity of the method was proved in defined concentrations ranges for gentamicin (0.32–1.04 mg mL−1), methylparaben (0.0072–0.0234 mg mL−1) and propylparaben (0.0008–0.0026 mg mL−1). Relative standard deviations calculated for all analytes in precision testing were 2PO4. Finally, the method was successfully applied for quantitative determination of gentamicin and parabens in commercially available solution for injection. Proposed HPLC method is found to be promising in terms of simplicity, analysis times and non-use of derivatization and ion-pair agents.

Polymeric film-forming systems have emerged as an esthetically acceptable option for targeted, less frequent and controlled dermal drug delivery. However, their dynamic nature (rapid evaporation of solvents leading to the formation of thin films) presents a true characterization challenge. In this study, we tested a tiered characterization approach, leading to more efficient definition of the quality target product profiles of film-forming systems. After assessing a number of physico-chemico-mechanical properties, thermal, spectroscopic and microscopic techniques were introduced. Final confirmation of betamethasone dipropionate-loaded FFS biopharmaceutical properties was sought via an in vitro skin permeation study. A number of applied characterization methods showed complementarity. The sample based on a combination of hydrophobic Eudragit® RS PO and hydroxypropyl cellulose showed higher viscosity (47.17 ± 3.06 mPa·s) and film thickness, resulting in sustained skin permeation (permeation rate of 0.348 ± 0.157 ng/cm2 h), and even the pH of the sample with Eudragit® NE 30D, along with higher surface roughness and thermal analysis, implied its immediate delivery through the epidermal membrane. Therefore, this study revealed the utility of several methods able to refine the number of needed tests within the final product profile.

The current study describes the experimental design guided development of PEGylated nanoemulsions as parenteral delivery systems for curcumin, a powerful antioxidant, as well as the evaluation of their physicochemical characteristics and antioxidant activity during the two years of storage. Experimental design setup helped development of nanoemulsion templates with critical quality attributes in line with parenteral application route. Curcumin-loaded nanoemulsions showed mean droplet size about 105 nm, polydispersity index

Traditional drug discovery strategies are usually focused on occupancy of binding sites that directly affect functions of proteins. Hence, proteins that lack such binding sites are generally considered pharmacologically intractable. Modulators of protein activity, especially inhibitors, must be applied in appropriate dosage regimens that often lead to high systemic drug exposures in order to maintain sufficient protein inhibition in vivo. Consequently, there is a risk of undesirable off-target drug binding and side effects. Recently, PROteolysis TArgeting Chimera (PROTAC) technology has emerged as a new pharmacological modality that exploits PROTAC molecules for induced protein degradation. PROTAC molecule is a heterobifunctional structure consisting of a ligand that binds a protein of interest (POI), a ligand for recruiting an E3 ubiquitin ligase (an enzyme involved in the POI ubiquitination) and a linker that connects these two. After POI-PROTAC-E3 ubiquitin ligase ternary complex formation, the POI undergoes ubiquitination (an enzymatic post-translational modification in which ubiquitin is attached to the POI) and degradation. By merging the principles of photopharmacology and PROTAC technology, photocontrollable PROTACs for spatiotemporal control of induced protein degradation have recently emerged. The main advantage of photocontrollable over conventional PROTACs is the possible prevention of off-target toxicity thanks to local photoactivation. Tradicionalne strategije razvoja lekova su obično osvrnute na okupiranje vezujućih mesta koja direktno utiču na funkcije proteina. Stoga se proteini koji nemaju takva vezujuća mesta generalno smatraju farmakološki nedodirljivim. Modulatori aktivnosti proteina, naročito inhibitori, koriste se u režimima doziranja koji često dovode do preterane sistemske izloženosti leku, a sve u cilju održavanja dovoljne inhibicije proteina in vivo. Posledično, postoji rizik od neželjenog vezivanja leka van svog primarnog mesta dejstva i neželjenih efekata. Nedavno je predstavljena tehnologija dirigovane proteolize (PROteolysis TArgeting Chimera, PROTAC) kao novi farmakološki modalitet koji koristi PROTAC molekule za indukovanu degradaciju proteina. PROTAC molekuli su heterobifunkcionalne strukture sačinjene od liganda koji se vezuje za protein od interesa (POI), liganda za regrutovanje E3 ubikvitin ligaze (enzima uključenog u ubikvitinaciju POI) i linkera koji ih povezuje. Nakon formiranja ternarnog kompleksa POI-PROTAC-E3 ubikvitin ligaza, POI podleže ubikvitinaciji (enzimskoj post-translacionoj modifikaciji u kojoj se ubikvitin vezuje za POI) i degradaciji. Integrisanjem principa fotofarmakologije i PROTAC tehnologije, nedavno su nastali su fotokontrolisani PROTAC molekuli za prostorno-vremensku kontrolu indukovane degradacije proteina. Zahvaljujući lokalnoj fotoaktivaciji, glavna prednost fotokontrolisanih nad konvencionalnim PROTAC molekulima je moguća prevencija toksičnosti koja nastaje usled dejstva van primarnog biološkog targeta.

The study focused on formulation of carmellose sodium hydrogels and nonionic microemulsions with 5% and 10% of levetiracetam and investigation of drug concentration influence on their physicochemical characteristics and in-use stability as well as influence of drug concentration and carrier type on in vitro drug release and in vivo antihyperalgesic/antiedematous activity in a rat model of localized (intraplantar) carrageenan-induced inflammation. Hydrogels were pseudoplastic semisolids with thixotropy and pH 7.37–7.58. Microemulsions were low viscous Newtonian nanodispersions of oil droplets (13.11–15.11 nm) in water, with pH 4.01–4.64. Physical stability of the investigated systems was preserved over the 3-month storage under ambient conditions. Levetiracetam release followed zero order and Korsmeyer-Peppas models (R2 ≥ 0.99) reflecting the combined effects of drug concentration and carrier viscosity. All levetiracetam-loaded formulations produced significant reduction of hyperalgesia and paw swelling induced by carrageenan (p < 0.001). Their efficacy in exerting antihyperalgesic activity was significantly higher than that observed with the reference 5% ibuprofen hydrogel preparation (up to 6 h) (p < 0.001), while antiedematous activity was comparable with the reference product. No erythema and visible blood vessels were observed in a rat ear test. The study demonstrated percutaneous delivery of levetiracetam as useful and safe therapeutic option for localized inflammatory pain with potential to overcome the insufficient efficacy of topically applied nonsteroidal anti-inflammatory drugs in the form of a hydrogel. [Figure not available: see fulltext.]. © 2020, Controlled Release Society.

Altered gamma-aminobutyric acid (GABA) function is consistently reported in psychiatric disorders, normal aging, and neurodegenerative disorders and reduced function of GABA interneurons is associated with both mood and cognitive symptoms. Benzodiazepines (BZ) have broad anxiolytic, but also sedative, anticonvulsant and amnesic effects, due to nonspecific GABA-A receptor (GABAA-R) targeting. Varying the profile of activity of BZs at GABAA-Rs is predicted to uncover additional therapeutic potential. We synthesized four novel imidazobenzodiazepine (IBZD) amide ligands and tested them for positive allosteric modulation at multiple α-GABAA-R (α-positive allosteric modulators), pharmacokinetic properties, as well as anxiolytic and antidepressant activities in adult mice. Efficacy at reversing stress-induced or age-related working memory deficits was assessed using a spontaneous alternation task. Diazepam (DZP) was used as a control. Three ligands (GL-II-73, GL-II-74, and GL-II-75) demonstrated adequate brain penetration and showed predictive anxiolytic and antidepressant efficacies. GL-II-73 and GL-II-75 significantly reversed stress-induced and age-related working memory deficits. In contrast, DZP displayed anxiolytic but no antidepressant effects or effects on working memory. We demonstrate distinct profiles of anxiolytic, antidepressant, and/or pro-cognitive activities of newly designed IBZD amide ligands, suggesting novel therapeutic potential for IBZD derivatives in depression and aging.

The application assessment of different programs was performed with equivalence tests for method transfer pro second-order derivative spectrophotometry. The digital second-order derivative spectra were calculated on different instruments; GBC Scientific Equipment Cintra 20 (Cintral v.2.6 and Spectral v.1.70 software programs) and Thermo Scientific Evolution 300 (VISIONPro software) were analyzed using the amplitude A/B ratio (A = 2D265,263; B = 2D263,261). Amplitude A/B ratio is the resolution parameter for derivative spectrophotometry prescribed in European Pharmacopoeia. The obtained values for A/B ratio were either very similar or significantly different among programs: 0.669 (Cintral v.2.6), 0.549 (Spectral v.1.70), 0.556 (medium indirect VISIONPro), 0.557 (one-step Savitzky–Golay 7 VISIONPro), 0.689 (two-step Savitzky–Golay 7 VISIONPro). Method transfer was possible between Spectral v.1.70 and VISIONPro (medium indirect and one-step Savitzky–Golay 7), but the values obtained in Cintral v.2.6 were not comparable to the other programs. The absorbance data exported from both instruments were additionally calculated in OriginPro8 which provided almost the same mean A/B values (0.627 Cintral v.2.6; 0.624 VISIONPro), confirming that the two instruments recorded the same zero-order spectra. The calculation of resolution parameter could be used for verification of program comparison, which would enable transfer between sender and receiver laboratory. The accordance between program algorithms was confirmed when acceptable differences for values of resolution parameter (A/B ratios) were achieved.

It is unclear whether GABAA receptors (GABAARs) that contain the α3-subunit are substantially involved in the anxiolytic effects of benzodiazepines (BDZs). In the present study, we tested YT-III-31, a newer BDZ ligand with functional preference for α3βγ2 GABAARs, in two paradigms of unconditioned anxiety, the open field and elevated plus maze in rats. The effective dose of YT-III-31 (2 mg/kg) displayed a clear anxiolytic-like profile, unhampered by sedative action, in both tests. At a higher dose (10 mg/kg), YT-III-31 induced ataxia in the rotarod and sedation in spontaneous locomotor activity test. The latter effect was preventable by flumazenil and βCCt, the non-selective and α1βγ2 GABAAR affinity-selective antagonist, respectively, demonstrating that sedative properties of YT-III-31, when attained, are mediated by the α1γ2 site. To elucidate the receptor substrate of subtle behavioral differences between YT-III-31 and diazepam, we approximated in vivo receptor potentiation for both ligands, based on estimated unbound concentrations in rat brains. Far different from diazepam, YT-III-31 has significantly lower affinity for the α1γ2 over other BDZ-sensitive sites, and at lower doses (1–2 mg/kg) was devoid of potentiation at α1βγ2 GABAARs. The approximation approach revealed a modest selectivity of YT-III-31 for α3γ2- in comparison to α2γ2 and α5γ2 binding sites, suggesting that its anxiolytic-like activity may not necessarily or predominantly reflect potentiation at α3βγ2 GABAARs. Nonetheless, as the anxiolytic effects are achievable at a dose devoid of any sedative potential, and having favorable safety (cytotoxicity) and metabolic stability profile, YT-III-31 represents a valuable candidate for further translational research.

pKa values of five β-hydroxy-β-arylalkanoic acids and ibuprofen were determined using the RP-HPLC method. Stationary phase was octadecyl modified (C-18) silica gel, and mobile phase was a mixture of methanol and one of nine different buffers (60:40, v/v). wspH values were measured after mixing methanol with an appropriate buffer. The mean retention time of each compound was plotted against wspH of each mobile phase. The inflection point of each sigmoidal curve represented wspK a of the compound. Using wspK a in already known equations for the specific methanol/buffer mixture, wwpK a values were calculated. Obtained pKa values for synthesized compounds were in a narrow range from 3.34-3.81 and pKa for ibuprofen was 4.45. Predicted pKa values for these compounds in SPARC software showed good correlation with experimental pKa values (R2=0.8048).

This work aimed to deepen the lately acquired knowledge about parenteral nanoemulsions as carriers for brain delivery of risperidone, a poorly water-soluble antipsychotic drug, through establishing the prospective relationship between their physicochemical, pharmacokinetic, biodistribution, and behavioral performances. For this purpose, two optimized risperidone-loaded nanoemulsions, stabilized by lecithin or lecithin/polysorbate 80 mixture, and costabilized by sodium oleate, were produced by high-pressure homogenization. The characterization revealed the favorable droplet size, narrow size distribution, high surface charge, with proven stability to autoclaving and long-term stability for at least one year at 25 +/- 2 degrees C. Pharmacokinetic and tissue distribution results demonstrated improved plasma, liver, and brain pharmacokinetic parameters, resulting in 1.2-1.5-fold increased relative bioavailability, 1.1-1.8-fold decreased liver distribution, and about 1.3-fold improved brain uptake of risperidone active moiety following intraperitoneal administration of nanoemulsions relative to solution in rats. In behavioral study, investigated nanoemulsions showed pronounced reduction in basal and, more pertinently, amphetamine-induced locomotor activity in rats, with an early onset of antipsychotic action, and this effect lasted at least 90 min after drug injection. Together, these findings corroborate the applicability of parenteral nanoemulsions as carriers for enhanced brain delivery of risperidone, further suggesting their promise in acute psychosis treatment or other emergency situations.

We previously demonstrated that lipopolysaccharide (LPS) administered intraperitoneally (i.p.) to pregnant Wistar rat dams, at embryonic days 15 and 16 (E15/16), induced a decrease of baseline locomotor activity and diminished reactivity to amphetamine in adult female offspring. In the present study we aimed to assess the duration of LPS-induced maternal immune activation (MIA) and investigate possible changes in levels of main neurotransmitters in fetal brain during MIA. We hypothesized that the observed behavioral changes may be linked with MIA-induced disturbance of prenatal GABAergic system development, especially with alpha 5 GABA(A) receptors (alpha 5GABA(A)Rs), expression of which takes place between E14 and E17. Thereafter, we set to investigate if later potentiation of alpha 5GABA(A)Rs in offspring's preadolescence (from postnatal day 22-28) could prevent the deficit in locomotor reactivity to amphetamine observed in adulthood, at postnatal day P60. The elevation of IL-6 in amniotic fluid 6 h after LPS treatment (100 mu g/kg, i.p.) at E15 was concurrent with a significant increase of GABA and decrease of glutamate concentration in fetal brain. Moreover, repeated administration of MP-III-022, a selective positive allosteric modulator of alpha 5GABA(A)Rs, at a dose (2 mg/kg daily, i.p.) derived from a separate pharmacokinetic study, prevented the LPS-induced decrease in locomotor reactivity to amphetamine (0.5 mg/kg, i.p.) in adult females. These results were not mirrored in the parallel set of experiments with male offspring from LPS-treated rats. The results suggest that pharmacological potentiation of alpha 5GABA(A)Rs activity in preadolescence may ameliorate at least some of adverse consequences of exposure to MIA in utero.

Chronic stress conditions can lead to considerable and extensible changes in physiological and psychological performances, and in emergence of risk for various somatic diseases. On the other hand, the neuropeptide oxytocin is reported to increase the resistance of the organism to stress and modulate activity of autonomic nervous system. Chronic corticosterone administration is used as a rat model for a state observed in terms of chronic stress exposure, when negative feedback mechanism of hypothalamus-pituitary-adrenal axis activity is disrupted. In our study, we aimed to investigate whether chronic administration of oxytocin (10114400 pI/day for 14 days, s.c.) influenced adrenal gland morphology and activity in adult male Wistar rats during long-term corticosterone administration via drinking water (100 mg/L for 21 days). We examined the influence of treatments on the levels of adrenal gland hormones, corticosterone, adrenaline and noradrenaline, as well as their response to an acute stress challenge evoked by 15-min forced swimming. In addition, the expression of two main monoamine transporters, the noradrenaline transporter (NAT) and vesicular monoamine transporter 2 (VMAT2) in adrenal medulla was measured in the rats exposed to acute stress. Our results showed that oxytocin treatment prevented corticosterone-induced decrease in body weight gain, attenuated adrenal gland atrophy by increasing glandular weight, and the area of the zona fasciculate and reticularis. Chronic corticosterone intake blunted the response of all measured hormones to acute stress, whereas concomitant oxytocin treatment reversed adrenaline and noradrenaline response to acute stress. Furthermore, in adrenal medulla, oxytocin produced significant vasodilatation and stimulated expression of both catecholamine transporters detected both on mRNA and protein level. Our data suggest that oxytocin, by reducing atrophy of adrenal gland, and by increasing catecholamine storage capacity, may be beneficial in conditions accompanied with high glucocorticoid levels, such as chronic stress exposure. (C) 2017 Elsevier Ltd. All rights reserved.

Introduction: The significance of oxidative stress in pathogenesis of childhood asthma was recognized, but its role in the clinical manifestations of disease is still unclear. Materials and Methods: The study was conducted in 96 asthmatic children. The urinary biomarker of oxidative stress, 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG/creatinine) was determined by using HPLC-MS/MS. ELISA was performed to measure myeloperoxidase (MPO) and Cu,Zn-superoxide dismutase (Cu, Zn-SOD) in serum. Results: Logistic regression analysis revealed that female gender, tobacco smoke exposure, and increased 8-oxodG/creatinine were associated with risk for intermittent asthma, while the positive allergy test and increased Cu, Zn-SOD were associated with eczema in asthmatic children. Higher MPO (p = 0.033), and percent of granulocytes (p = 0.030) were found in severe persistent asthma in comparison to intermittent or mild persistent asthma. Conclusion: The main findings that TSE-induced oxidative stress is a risk for intermittent asthma and eczema may be clinically significant for the disease prevention and therapeutic improvements.

The objective of this work was to develop low-energy nanoemulsions for enhanced dermal delivery of curcumin, using monoterpene compounds eucalyptol (EUC) and pinene (PIN) as chemical penetration enhancers. Spontaneous emulsification was the preparation method. All formulations contained 10% of the oil phase (medium-chain triglycerides (MCT), or their mixture with EUC or PIN). Formulations were stabilized by the combination of polysorbate 80 and soybean lecithin (surfactant-to-oil-ratio=1). Concentration of curcumin was set to 3 mg/ml. Average droplet diameter of all tested formulations ranged from 102 nm to 132 nm, but the ones containing monoterpenes had significantly smaller size compared to the MCT formulation. Such finding was profoundly studied through electron paramagnetic resonance spectroscopy, which proved that the presence of monoterpenes modified the nanoemulsions’ interfacial environment, resulting in droplet size reduction. The release study of curcumin (using Franz cells) demonstrated that the cumulative amount released after 6 h of the experiment was 10.1 ± 0.2% for the MCT nanoemulsions, 13.9 ± 0.1% and 14.0 ± 0.2% for PIN and EUC formulations, respectively. In vivo tape stripping revealed their performances in delivering curcumin into the skin, indicating the following order: EUC>MCT>PIN. The formulation with EUC was clearly the most successful, giving the highest cumulative amount of curcumin that penetrated per surface unit: 34.24±5.68 µg/cm2. The MCT formulation followed (30.62±2.61 µg/cm2) and, finally, the one with PIN (21.61±0.11 µg/cm2). These results corelated with curcumin's solubility in the chosen oils: 4.18±0.02 mg/ml for EUC, 1.67±0.04 mg/ml for MCT and 0.21±0.01 mg/ml for PIN. Probably, higher solubility in the oil phase of the nanoemulsion promoted curcumin's solubility in the superficial skin layers, providing enhanced penetration. This is the peer-reviewed version of the article: European Journal of Pharmaceutical Sciences, 2020, 142, 105135, [https://doi.org/10.1016/j.ejps.2019.105135] The published version: [http://cer.ihtm.bg.ac.rs/handle/123456789/3309]

As the number of poorly soluble drugs is increasing, nanocrystals have become very interesting due to wide range of application possibilities. Curcuminwas used as a model active ingredient in this work. Even though it has many proven positive effects, due to its physicochemical issues, its possibilities have not been fully exploited. The goal of this work was to select optimal conditions for a top-down method for curcumin nanosuspension production, and to perform their comprehensive characterization applying complementary methodologies: dynamic light scattering, polarization and atomic force microscopy, thermal analysis, X-ray powder diffraction, antioxidant activity evaluation, release kinetics assessment, and screening of potential biological effects applying cell viability assays on normal human lung fibroblasts, human melanoma and human adenomacarcinoma cells. After 30 min of milling, nanosuspensions stabilized by polysorbate 80 and by its combinations with sucrose palmitate showed good stability, while curcumin crystal structure was unaltered. Obtained nanocrystals were well defined, with average diameter 120–170 nm and PDI of about 0.25, zeta potential was below −30 mV and pH~5 for all formulations. Nanodispersions exhibited high antioxidant potential and improved dissolution rate compared to the corresponding coarse dispersions. Although curcumin nanodispersions exhibited significant antiproliferative effect to each cancer cell line, the highest effect was towards adenocarcinoma cells.

Introduction Chitosanisanunbranchedbinaryheteropolysaccaride obtained from chitin by partial alkaline deacetylation. Chitosan is biocompatible and biodegradable polymer used in pharmacy and biomedical investigations. In dietary supplements chitosan is used for weight loss and cholesterol-lowering properties. Aim The aims of chitosan's analyses of capsules were to determine: the weight variation tests for chitosan in 0.15 g chitosan/capsule, chitosan characteristics - degree of deacetylation DDA(%) via comparison of proposed modifications of FTIR-ATR spectroscopy and acid-base titration; moisture and ash content and functional characteristics - water binding capacity (WBC) as well as fat binding capacity (FBC). Method Tests were performed for dietary supplement on market TIENS (0.15 and 0.25 g pure chitosan/capsule). For DDA(%) FTIR spectra were recorded on Nicolet iS10 Thermo-Scientific USA (ATR technique) and for acid-base titration-retitration technique with indicator bromphenol blue was applied. Loss on drying determined at 105°C and 60°C (2 h) and ash at 650°C (4 h). For WBC (10.00 ml of redestilled water) and FBC (10.00 ml soybean, corn or sunflower oil) were placed in cuvetes (30 ml) and centrifuged 3,500 rpm (25 min). The weight variation tests for 0.15 g chitosan/capsule from 2 series each of 20 weights gave x=0.1498±0.0063 g (99.87% of declared mass). Applying FTIRATR spectroscopy (two equations with absorbance ratio of bands A1655/A3450 and A1320/A1420 with corresponding baselines) provided the most harmonized DDA(%) of 92.66% (baseline b for peak at 1650 cm-1) and 89.40% (baseline b6(A1320) and b9(A1420) in relation with acid-base titration 91.49%. Moisture content was x̄1=7.55% (105°C) and x̄2=7.03% (60°C) (acceptable values

Passive gastrointestinal absorption and membrane retention of twelve esters of (S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid (EDCP) and (S,S)-1,3-propanediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid (PDCP), as well as of these two non-esterified acids were estimated using PAMPA test. Artificial PAMPA membrane used in this study for the simulation of gastrointestinal barrier was solution of egg lecithin in dodecane (1 % w/v). All tested compounds belong to class III (high membrane retention and low permeation), whereas EDCP, dipentyl ester of PDCP (DPE-PDCP) and diisopentyl ester of PDCP (DIPE-PDCP) belong to class I (negligible membrane retention and low permeation). Finally, quantitative structure – permeability and structure – retention relationships models were created in order to find quantitative relationships between physico-chemical properties of tested compounds and PAMPA membrane permeability/membrane retention parameters. Statistically the most reliable models were analysed and used for the design of new compounds for which favourable membrane permeability and retention can be expected. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3870] This is the peer-reviewed version of the following article: Tubić, B.; Dobričić, V.; Poljarević, J.; Savić, A.; Sabo, T.; Marković, B. Estimation of Passive Gastrointestinal Absorption and Membrane Retention Using PAMPA Test, Quantitative Structure-Permeability and Quantitative Structure-Retention Relationship Analyses of Ethylenediamine-N,N’-Di-2-(3-Cyclohexyl)Propanoic Acid and 1,3-Propanediamine-N,N’-Di-2-(3-Cyclohexyl)Propanoic Acid Derivatives. Journal of Pharmaceutical and Biomedical Analysis 2020, 184. [https://doi.org/10.1016/j.jpba.2020.113213]

In previously in vitro studies on different cell lines and in vivo on melanoma and 4T1 murine breast cancer and metastasis it was shown antiproliferative activity for ester derivatives of (S,S)-ethylenediamine-N,N′-di-2-(3-cyclohexyl)propanoic acid, and (S,S)-1,3-propanediamine-N,N′-di-2-(3-cyclohexyl)propanoic acid. The aim of this study was to predict membrane permeability by parallel artificial membrane permeability assay (PAMPA), molecular mechanism of action, metabolites and absorption, distribution, metabolism, toxicity—ADMET properties for observed substances using in vitro and in silico methods. Obtained results of PAMPA show the best membrane permeability of ethyl esters analogs (DE-EDCP and DE-PDCP) and refer to the hypothesis that the retention in cell membrane is important for cytotoxic activity of investigated substances. Prediction of main metabolic pathways was performed by the Metabolizer software and it was obtained that the major metabolic reactions were the hydrolyses of ester and subsequently intramolecular cyclization. Toxicity of investigated substances and their potential metabolites are lower than toxicity of observed official cytotoxic drugs. Based on the results obtained by the Molecular docking, it can be assumed that the antiproliferative effects of the investigated substances were realized through the multiple mechanisms by potential metabolites: acids, lactam carboxylate and lactam alkyl esters, while the esters are probably a prodrug substance with favorable properties to provide sufficient bioavailability at the target of action. Based on obtained results it can be proposed there to be investigated the existence of the metabolites: lactam carboxylate and lactam alkyl esters in biological materials.

This study aimed to investigate the potential of lecithin-based nanoemulsions costabilized by sucrose esters, with and without skin pretreatment with stainless steel microneedles, to improve delivery of aceclofenac, as a model drug, into/across the skin. The characterization revealed favorable droplet size (about 180 nm), narrow size distribution ( lt 0.15), high surface charge (about - 40 mV) and satisfying long-term stability (one year at 4 +/- 1 degrees C) of the formulation costabilized by sucrose palmitate, demonstrating a similar trend observed for the reference stabilized by widely used lecithin/polysorbate 80 combination. In vitro release/permeation testing and differential stripping on the porcine ear proved the superiority of the sucrose ester- over polysorbate-based nanoemulsion. However, in vitro findings were not fully indicative of the in vivo performances - no significant differences were observed between investigated formulations in pharmacokinetic profile and total amount of aceclofenac deposited in the rat skin 24 h after dosing, simultaneously pointing to delayed aceclofenac delivery into the systemic circulation. In addition, the ratio of plasma concentrations of aceclofenac and its major metabolite in rats, diclofenac, was remarkably changed after topical application of tested nanoemulsions compared to intravenous administration of aceclofenac solution. Finally, skin pretreatment with microneedles improved aceclofenac delivery into/across the rat skin from tested formulations, resulting in 1.4-2.1-fold increased bioavailability and 1.2-1.7-fold enhanced level of aceclofenac retained in the skin, as measured 24 h after administration. Moreover, the plasma concentrations of aceclofenac 24 h after application of tested formulations (lecithin/sucrose palmitate vs. lecithin/polysorbate 80) combined with microneedles (173.37 +/- 40.50 ng/ml vs. 259.23 +/- 73.18 ng/ml) were significantly higher than those obtained through intact skin (105.69 +/- 19.53 ng/ml vs. 88.38 +/- 14.46 ng/ml). However, obtained results suggest that combination of microneedles and sucrose palmitate-costabilized nanoemulsion could be useful to attain higher skin concentration, while combination of microneedles with polysorbate 80-costabilized nanoemulsion could be a preferable option for enhancing drug delivery into the bloodstream.

Altered γ-aminobutyric acid (GABA) function is consistently reported in psychiatric disorders, normal aging and neurodegenerative disorders, and reduced function of somatostatin - expressing GABA interneurons is associated with both mood and cognitive symptoms. Somatostatin-neurons signal in part through α5-subunit containing GABAA receptors (α5-GABAA-Rs) which are localized in brain regions implicated in emotion and cognition. We hypothesize that enhancing α5-GABAA-R activity has therapeutic potential for both mood and cognitive symptoms in stress-based and aging rodent models.We synthesized four novel imidazobenzodiazepine (IBZD) amide ligands, tested them for positive allosteric modulation at α5-GABAA-R (α5-PAM), pharmacokinetic properties, and for anxiolytic and antidepressant activities in adult mice. Pro-cognitive activity was tested in adult mice submitted to chronic stress and in old mice. Diazepam (DZP), with broad PAM activity at GABAA-Rs, was used as a control.Three novel IBZD amide ligands (GL-II-73, GL-II-74 and GL-II-75) demonstrated adequate brain penetration, affinity and α5-PAM activity, and metabolic stability for in vivo studies. GL-II-73/74/75 showed significant anxiolytic and antidepressant efficacies in adult mice. GL-II-73 and GL-II-75 significantly reversed cognitive deficits induced by stress or occurring throughout normal aging. This activity was maintained after sub-chronic administration for GL-II-73. In contrast DZP displayed anxiolytic but no antidepressant or pro-cognitive activities.We demonstrate for the first time the potential for combined anxiolytic, antidepressant and pro-cognitive therapeutic, mediated by newly designed IBDZ amide ligands with efficacy at α5-GABAA-Rs. These results suggest a novel therapeutic approach targeting both mood and cognitive symptoms in depression and/or aging.

The objective of this work was to investigate and profoundly characterize low-energy nanoemulsions as multifunctional carriers, with slight reference to dermal administration. An evidence-based approach was offered for deepening the knowledge on their formation via spontaneous emulsification. Curcumin, a compound of natural origin, potentially powerful therapeutic, was chosen as a model API. Due to curcumin's demanding properties (instability, poor solubility, low permeability), its potentials remain unreached. Low-energy nanoemulsions were considered carriers capable of overcoming imposed obstacles. Formulation consisting of Polysorbate 80 and soybean lecithin as stabilizers (9:1, 10%), medium-chain triglycerides as the oil phase (10%) and ultrapure water was selected for curcumin incorporation in 3 different concentrations (1, 2 and 3 mg/mL). Physicochemical stability was demonstrated during 3 months of monitoring (mean droplet size: 111.3-146.8 nm; PDI LT 0.2; pH: 4.73-5.73). Curcumin's release from developed vehicles followed Higuchi's kinetics. DPPH (IC50 = 0.1187 mg/ mL) and FRAP (1.19 +/- 0.02 mmol/g) assays confirmed that curcumin acts as a potent antioxidant through different mechanisms, with no alterations after incorporation in the formulation. High biocompatibility in line with antigenotoxic activity of curcumin-loaded formulations (protective and reparative) was estimated through Comet assay. A multidisciplinary approach is needed to fully characterize developed systems, directing them to more concrete application possibilities. This is the peer-reviewed version of the article: I. Nikolic, D. Jasmin Lunter, D. Randjelovic, et. al., Curcumin-loaded low-energy nanoemulsions as a prototype of multifunctional vehicles for different administration routes: physicochemical and in vitro peculiarities important for dermal application, International, Journal of Pharmaceutics, 2018, 550, 1-2, 333-346, DOI: [https://doi.org/10.1016/j.ijpharm.2018.08.060] The published version: [https://cer.ihtm.bg.ac.rs/handle/123456789/2425]

The separation and characterization of the unknown degradation product of second-generation antipsychotic drug ziprasidone are essential for defining the genotoxic potential of the compound. The aim of this study was to develop a simple UHPLC method coupled with tandem mass spectrometry (MS/MS) for chemical characterization of an unknown degradant, and the separation and quantification of ziprasidone and its five main impurities (I-V) in the raw material and pharmaceuticals. Chromatographic conditions were optimized by experimental design. The MS/MS fragmentation conditions were optimized individually for each compound in order to obtain both specific fragments and high signal intensity. A rapid and sensitive UHPLC-MS/MS method was developed. All seven analytes were eluted within the 7 min run time. The best separation was obtained on the Acquity UPLC BEH C-18 (50 x 2.1 mm x 1.7 mu m) column in gradient mode with ammonium-formate buffer (10 mm; pH 4.7) and acetonitrile as mobile phase, with the flow rate of 0.3 mL min(-1) and at the column temperature of 30 degrees C. The new UHPLC-MS/MS method was fully validated and all validation parameters were confirmed. The fragmentation pathways and chemical characterization of an unknown degradant were proposed and it was confirmed that there are no structural alerts concerning genotoxicity.

Development and validation of a liquid chromatography - tandem mass spectrometry (LC-MS/MS) method for the determination of adapalene in pharmaceutical forms for skin application were presented. The MS/MS analysis of adapalene was performed by use of three mobile phases, consisted of acetonitrile and (a) 0.1 % formic acid, (b) 0.1 % trifluoroacetic acid and (c) 20 mM ammonium acetate. The strongest signals of parent ion and dominant product ion were obtained in negative mode by use of the mobile phase (c). Validation of this method was performed according to the ICH guidelines. Small variations of selected chromatographic parameters (concentration of ammonium acetate, mobile phase composition, column temperature and flow rate) did not affect qualitative and quantitative system responses significantly, which proved method’s robustness. The method is specific for the determination of adapalene. Linearity was proved in the concentration range 6.7 - 700.0 ng mL-1 (r = 0.9990), with limits of detection and quantification 2.0 ng mL-1 and 6.7 ng mL-1, respectively. Accuracy was confirmed by calculated recoveries (98.4 % - 101.5 %). Precision was tested at three levels: injection repeatability, analysis repeatability and intermediate precision. Calculated relative standard deviations were less than 1, 2 and 3 %, respectively. [Projekat Ministartsva nauke Republike Srbije, br. OI172041 i br. TR34031]

The paper deals with the sense of writing poetry as a form of text immanence that is antinomous to the contemporary age, which is also an alternative system of thought, of transformation, of imitation and of critical redefinition of the reality of that contemporary age. At the same time, poetry is a neglected, peripheral literary genre, but also a hyperbolized fictional form that opens the way to an alternative victory of opinions and feelings. Essayistic in structure, the paper discusses several poems and the poetics of three 20th century Serbian and Yugoslav Modernists (Kosovel, Dis, Crnjanski), in order to show, on the basis of their developing and differentiated poetic self-consciousness, what sense the writing of poetry might have in the 21st century. In these instances of poetics, paradigmatic of poetic self-consciousness in general, not all the possibilities of the sense of creativity and action have been exhausted, nor the poetic solutions leading to it.

Reportedly, negative modulation of α5 GABAA receptors may improve cognition in normal and pharmacologically-impaired animals, and such modulation has been proposed as an avenue for treatment of cognitive symptoms in schizophrenia. This study assessed the actions of PWZ-029, administered at doses (2, 5, and 10 mg/kg) at which it reached micromolar concentrations in brain tissue with estimated free concentrations adequate for selective modulation of α5 GABAA receptors, in three cognitive tasks in male Wistar rats acutely treated with the noncompetitive N-methyl-d-aspartate receptor antagonist, MK-801 (0.1 mg/kg), as well in tests of locomotor activity potentiated by MK-801 (0.2 mg/kg) or amphetamine (0.5 mg/kg). In a hormetic-like manner, only 5 mg/kg PWZ-029 reversed MK-801-induced deficits in novel object recognition test (visual recognition memory), whereas in the Morris water maze, the 2 mg/kg dose of PWZ-029 exerted partial beneficial effects on spatial learning impairment. PWZ-029 did not affect recognition memory deficits in social novelty discrimination procedure. Motor hyperactivity induced with MK-801 or amphetamine was not preventable by PWZ-029. Our results show that certain MK-801-induced memory deficits can be ameliorated by negative modulation of α5 GABAA receptors, and point to the need for further elucidation of their translational relevance to cognitive deterioration in schizophrenia.

We previously demonstrated that lipopolysaccharide (LPS) administered intraperitoneally (i.p.) to pregnant Wistar rat dams, at embryonic days 15 and 16 (E15/16), induced a decrease of baseline locomotor activity and diminished reactivity to amphetamine in adult female offspring. In the present study we aimed to assess the duration of LPS-induced maternal immune activation (MIA) and investigate possible changes in levels of main neurotransmitters in fetal brain during MIA. We hypothesized that the observed behavioral changes may be linked with MIA-induced disturbance of prenatal GABAergic system development, especially with α5 GABAA receptors (α5GABAARs), expression of which takes place between E14 and E17. Thereafter, we set to investigate if later potentiation of α5GABAARs in offspring’s preadolescence (from postnatal day 22 to 28) could prevent the deficit in locomotor reactivity to amphetamine observed in adulthood, at postnatal day P60. The elevation of IL-6 in amniotic fluid 6 h after LPS treatment (100 μg/kg, i.p.) at E15 was concurrent with a significant increase of GABA and decrease of glutamate concentration in fetal brain. Moreover, repeated administration of MP-III-022, a selective positive allosteric modulator of α5GABAARs, at a dose (2 mg/kg daily, i.p.) derived from a separate pharmacokinetic study, prevented the LPS-induced decrease in locomotor reactivity to amphetamine (0.5 mg/kg, i.p.) in adult females. These results were not mirrored in the parallel set of experiments with male offspring from LPS-treated rats. The results suggest that pharmacological potentiation of α5GABAARs activity in preadolescence may ameliorate at least some of adverse consequences of exposure to MIA in utero.

Molecular docking studies were performed on 18 17β-carboxamide steroids in order to select compounds with potential local anti-inflammatory activity. These derivatives are amides of cortienic acids (obtained from hydrocortisone, prednisolone, and methylprednisolone) with methyl or ethyl esters of six amino acids. Interactions with the glucocorticoid receptor (GR), binding energies and ligand efficiency values of these compounds were compared with dexamethasone and cortienic acid obtained from prednisolone (inactive metabolite). On the basis of molecular docking studies, seven compounds were selected and their binding affinities for the GR were predicted by use of the exponential model created in this study. Subsequently, selected compounds were synthesized in good yields by use of modified N,N'-dicyclohexylcarbodiimide (DCC)/1-hydroxybenzotriazole (HOBt) coupling procedure. Finally, the local anti-inflammatory activity of the synthesized compounds was examined by use of the croton oil-induced ear edema test. In vivo evaluation of systemic side effects as well as in silico prediction of metabolism were performed on the derivative with the best local anti-inflammatory activity. The combination of molecular docking studies and the exponential model for the GR binding affinity prediction could be used as an in silico tool for the rational design of novel 17β-carboxamide steroids with potentially better biological profile than dexamethasone.

Set of nine angiotensin-converting enzyme inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril, ramipril, benazepril, perindopril and moexipril) were studied to evaluate the correlation between their intestinal absorption and salting-out thin-layer chromatography hydrophobicity parameters ( R M 0 or C0) obtained by ascending technique applying four different salts, (NH4)2SO4, NH4NO3, NH4Cl and NaCl as mobile phases. The best correlations between KOWWIN log P and both hydrophobicity parameters, R M 0 and C0, (R2 > 0.850) were observed for NaCl (1.0–3.0 M) while the lowest R2 was obtained for (NH4)2SO4 (0.649 and 0.427, respectively) due to highest salting-out effect of (NH4)2SO4. The effect of selected inorganic salts in the salting-out mobile phases, on the solutes solubility and retention was evaluated. The topological polar surface area should be selected as independent variable (only this molecular descriptor showed low correlation with chromatographic hydrophobicity parameters) for multiple linear regression analysis, to obtain reliable correlation between angiotensin-converting enzyme inhibitor's intestinal absorption data and salting-out thin-layer chromatograpic hydrophobicity parameters. These correlations provide R2 = 0.823 for R M 0 or R2 = 0.799 for C0 indicating good relationship between predicted and literature available intestinal absorption (ranged from 22% to 70%) of investigated angiotensin-converting enzyme inhibitors. The proposed in vitro model was checked with three in addition experimentally analyzed drugs, zofenopril, trandolapril and captoril. The satisfactory absorption prediction was obtained for zofenopril and trandolapril, while divergence established for captopril resulted from considerably different structure.

In this paper, twenty-two 17 beta-carboxamide steroids were synthesized from five corticosteroids (hydrocortisone, prednisolone, methylprednisolone, dexamethasone and betamethasone) in two steps. The first step was periodic acid oxydation of these corticosteroids to corresponding cortienic acids and the second step was amidation of thus obtained cortienic acids with esterified L-amino acids. These compounds are potential soft corticosteroids with local anti-inflammatory activity in the skin. Parallel artificial membrane permeability assay (PAMPA) was applied in order to predict permeability and retention of these compounds in human skin. Comparison of permeability and retention parameters between 17 beta-carboxamide steroids and corresponding corticosteroids was performed. Compounds with significantly higher retention were identified and the derivative that does not have significantly higher permeability was underlined. Molecular structures of all compounds were optimized by use of Gaussian semiempirical/PM3 method. Geometrical, thermodynamic, physicochemical and electronical molecular parameters of the optimized structures were calculated and quantitative structure-property relationship (QSPR) analysis was performed in order to explain permeability and retention of these compounds. ANN-, PLS- and MLR-QSPR models were created. Quality of these models was evaluated by commonly used statistical parameters and the most reliable models were selected. Analyzing descriptors in the selected models, main molecular properties that influence permeability and retention in the PAMPA artificial membrane were identified. Based on these data, further structural modifications could be applied in order to increase retention without significant increase of permeability, which can positively affect potential local antiinflammatory activity of these compounds. Selected QSPR models could be used as in silico tool for predicting human skin permeability and retention of novel 17 beta-carboxamide steroids without performing PAMPA experiments.

Nanostructured lipid carriers (NLC) and nanoemulsions (NE) are colloid carriers which could improve dermal delivery of tacrolimus. The aims of this study were to evaluate effects of different formulation and process parameters on physicochemical characteristics and stability of lecithin-based NLC with glyceryl palmitostearate as solid and propylene glycol monocaprylate as liquid lipid and to compare the influence of different inner structure of tacrolimus-loaded NLC and corresponding NE on physicochemical characteristics, stability, entrapment efficiency, in vitro drug release and overall skin performance. Solid/liquid lipid ratio, total amount of lipids, homogenization pressure and cooling after the preparation were identified as critical variables in NLC development. Moreover, tacrolimus-loaded NLC emerged as more stabile carrier than NE. Differential stripping performed on porcine ear skin revealed significantly higher tacrolimus amount in stratum corneum from nanocarriers compared to referent ointment (Protopic®). Similarly the highest amount of tacrolimus in hair follicles was obtained using NLC (268.54 ± 92.38 ng/cm2), followed by NE (128.17 ± 48.87 ng/cm2) and Protopic® (77.61 ± 43.25 ng/cm2). Contrary, the highest permeation rate through full-thickness porcine ear skin was observed for Protopic®, implying that the selection of experimental setup is critical for reliable skin performance assessment. Overall, developed NLC could be suggested as promising carrier in a form of lotion for tacrolimus dermal delivery.

In this study a reversed phase HPLC method for rapid and simultaneous identification and quantification of doxylamine succinate, ephedrine sulfate, dextrometorphane hydrobromide, paracetamole and sodium benzoate in cough-cold syrup formulation was described. Separation was carried out on XTerraTM RP 18, Waters (150 mm x 4.6 mm column, 5 μm particle size). For the analysis of investigated substances gradient elution was used employing water, pH adjusted at 2.5 with 85 % ortophosphoric acid as the mobile phase A and acetonitrile as the mobile phase B. Detection was carried out by UV absorbance at 210 nm for doxylamine succinate, ephedrine sulfate, dextromethorphane hydrobromide and sodium benzoate and at 270 nm for paracetamole. The method was validated statistically for selectivity, linearity, precision, accuracy. U ovom radu opisana je brza, efikasna, ekonomična reverzno fazna HPLC metoda za identifikaciju i određivanje doksilamin-sukcinata, efedrin-hidrohlorida, dekstrometorfanhidrobromida, paracetamola kao aktivnih komponenti i natrijum-benzoata kao konzervansa u sirupu za kašalj. Razdvajanje komponenata, njihova identifikacija i određivanje postignuto je na C18 stacionarnoj fazi (XTerraTM RP 18, Waters (150 mm x 4,6 mm, 5 μm veličine čestica) uz gradijentno eluiranje sa mobilnom fazom koju čine voda (čiji je pH podešen na 2,5 sa ortofosfornom kiselinom) i acetonitril kao organski rastvarač. Za detekciju ispitivanih jedinjenja korišćen je UV/VIS detektor podešen na 210 nm (doksilamin sukcinata, efedrin-hidrohlorida, dekstrometorfan-hidrobromida i natrijum-benzoata) tj. 270 nm (paracetamol). Kako je definisana metoda namenjena za identifikaciju i određivanje aktivnih supstanci i konzervansa u sirupu za kašalj, od parametara validacije ispitani su: selektivnost/specifičnost, linearnost, tačnost i preciznost. Svaki od parametara je statistički potvrđen. Dobijene vrednosti statističkih parametara (r³ 0,999, CV£ 2 % i Recovery od 98 % - 102 %) ukazuju da je definisana RP- HPLC metoda pogodna za identifikaciju i određivanje doksilamin-sukcinata, efedrinhidrohlorida, dekstrometorfan-hidrobromida, paracetamola i natrijum-benzoata u sirupu za kašalj.

Context: Approaching of pharmaceutical and cosmetic industries in some aspects inevitably influence formulation of topical pharmaceuticals, urging researchers to introduce novel excipients with proven benefits over traditional ones. In that context, alkyl polyglucosides (APG) emerge as prominent natural-origin emulsifiers with numerous favorable features (biodegradability, dermatological acceptability, desirable sensory properties). Objective: To evaluate APG-stabilized bases (alone and upon addition of isopropyl alcohol) and their impact on skin performance. A simultaneous in vitro/in vivo skin absorption study was conducted to evaluate whether the tape stripping technique could be recommended as an in vivo tool for skin penetration assessment during formulation optimization process. Materials and methods: After a comprehensive physicochemical characterization, biopharmaceutical properties of APG-bases versus reference ones were assessed through a combined in vitro (release/permeation) and in vivo approach. Results and discussion: Physicochemical characterization revealed substantial difference in structural ordering due to the formation of various mesomorphic phases. The enhancer-loaded APG base resulted in significantly higher drug levels at all depths into the stratum corneum, indicating that the selected enhancer along with specific colloidal structure has increased the extent of drug delivery. Conclusion: Results recommend the investigated emulsifier for stabilization of topical drug delivery systems, not only for their ability to sustain the addition of isopropyl alcohol which proved to be a valuable enhancer, but also satisfactory skin absorption and tolerability when compared to samples stabilized by conventional emulsifier. Tape stripping proved to be a useful and yet inexpensive tool for in vivo trials, able to discriminate subtle differences in dermal availability.

This article focuses on the presence of the concept of dissimilitude in the selection of literary texts for children prescribed by the syllabi in Croatia and Serbia. The comparative analysis is based on providing a list of texts for the first cycle of education in the two syllabi through a concept-based (transcending the text) observation of dissimilitude, as well as a content-based (text-inherent) analysis of the presence of dissimilitude in these texts in its broadest sense. In the literary texts prescribed by the Republic of Croatia and the Republic of Serbia, the field of dissimilitude thematization can largely be attributed to the nature of the literary work itself, rather than the curricular or concept-based education policy behind the current syllabi. The paper presents results of the analyses of the two syllabi that are conceptually quite different. The aim of this paper is to compare educational strategies for teaching literature in two countries – Croatia and Serbia – by analysing the presence of dissimilitude in a selection of literary texts., U radu se razmatra prisutnost koncepta različitosti u izboru književnih tekstova za djecu koje propisuju nastavni programi u Hrvatskoj i Srbiji. Komparativna analiza polazi od popisa tekstova za prvi ciklus školovanja u oba programa i uočavanja koncepta različitosti u samim programskim koncepcijama (transcedentno tekstu), ali i sadržajima, putem analize prisustva najšire shvaćene teme različitosti u tim tekstovima (imanentno tekstu). U tekstovima propisanim u RH i RS s obzirom na polje tematizacije razlika se u najvećoj mjeri može pripisati prirodi djela, a ne programskoj i koncepcijskoj obrazovnoj politici važećih programa. U radu se iznose rezultati analiza programa koji su koncepcijski sasvim različiti. U odnosu na koncept različitosti u djelima oba programa razmatra se niz problema koji prate fenomen razlike. Cilj je rada usporediti obrazovne strategije nastave književnosti dviju zemalja – Hrvatske i Srbije – na primjeru analize prisustva koncepta različitosti u izboru književnog teksta.

The genetic and non-genetic factors that contribute to the development of chronic obstructive pulmonary disease (COPD) are still poorly understood. We investigated the potential role of genetic variants of xenobiotic-metabolising enzymes (glutathione-S-transferase M1, GSTM1; glutathione-S-transferase T1, GSTT1; microsomal epoxide hydrolase, mEH), oxidative stress (assessed by urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine, 8-oxodG/creatinine), sex, ageing and smoking habits on susceptibility to development of COPD and its severity in Serbian population. The investigated population consisted of 153 healthy subjects (85 males and 68 females) and 71 patients with COPD (33 males and 38 females). Detection of GSTM1*null, GSTT1*null, mEH Tyr113His and mEH His139Arg gene variants was performed by PCR/RFLP method. Urinary 8-oxodG was determined using HPLC-MS/MS, and expressed as 8-oxodG/creatinine. We revealed that increased urinary 8-oxodG/creatinine and leucocytosis are the strongest independent predictors for COPD development. Increased level of oxidative stress increased the risk for COPD in males [odds ratio (OR), 95% confidence interval (CI): 8.42, 2.26-31.28], more than in females (OR, 95% CI: 3.60, 1.37-9.45). Additionally, independent predictors for COPD were ageing in males (OR, 95% CI: 1.29, 1.12-1.48), while in females they were at least one GSTM1 or GSTT1 gene deletion in combination (OR, 95% CI: 23.67, 2.62-213.46), and increased cumulative cigarette consumption (OR, 95% CI: 1.09, 1.01-1.16). Severity of COPD was associated with the combined effect of low mEH activity phenotype, high level of oxidative stress and heavy smoking. In conclusion, early identification of GSTM1*null or GSTT1*null genotypes in females, low mEH activity phenotype in heavy smokers and monitoring of oxidative stress level can be useful diagnostic and prognostic biomarkers.