Silver Nanoparticles Synthesized from Abies alba and Pinus sylvestris Bark Extracts: Characterization, Antioxidant, Cytotoxic, and Antibacterial Effects

In recent years, phytofunctionalized AgNPs have attracted great interest due to their remarkable biological activities. In the present study, AgNPs were synthesized using Abies alba and Pinus sylvestris bark extracts. The chemical profile of these bark extracts was analyzed by LC-HRMS/MS. As a first step, the synthesis parameters (pH, AgNO₃ concentration, ratio of bark extract and AgNO₃, temperature, and reaction time) were optimized. The synthesized AgNPs were characterized by ATR-FTIR spectroscopy, DLS, SEM, EDX, and TEM. Their antioxidant, cytotoxic, and antibacterial properties were evaluated by the DPPH, ABTS, MTT, and broth microdilution assays, respectively. Abies alba and Pinus sylvestris bark extract-derived AgNPs were well-dispersed, spherical, small (average particle size of 9.92 and 24.49 nm, respectively), stable (zeta potential values of -10.9 and -10.8 mV, respectively), and cytotoxic to A-375 human malignant melanoma cells (IC₅₀ = 2.40 ± 0.21 and 6.02 ± 0.61 μg/mL, respectively). The phytosynthesized AgNPs also showed antioxidant and antibacterial effects.

Phyto-Functionalized Silver Nanoparticles Derived from Conifer Bark Extracts and Evaluation of Their Antimicrobial and Cytogenotoxic Effects

Silver nanoparticles synthesized using plant extracts as reducing and capping agents showed various biological activities. In the present study, colloidal silver nanoparticle solutions were produced from the aqueous extracts of Picea abies and Pinus nigra bark. The phenolic profile of bark extracts was analyzed by liquid chromatography coupled to mass spectrometry. The synthesis of silver nanoparticles was monitored using UV-Vis spectroscopy by measuring the Surface Plasmon Resonance band. Silver nanoparticles were characterized by attenuated total reflection Fourier transform infrared spectroscopy, Raman spectroscopy, dynamic light scattering, scanning electron microscopy, energy dispersive X-ray and transmission electron microscopy analyses. The antimicrobial and cytogenotoxic effects of silver nanoparticles were evaluated by disk diffusion and Allium cepa assays, respectively. Picea abies and Pinus nigra bark extract derived silver nanoparticles were spherical (mean hydrodynamic diameters of 78.48 and 77.66 nm, respectively) and well dispersed, having a narrow particle size distribution (polydispersity index values of 0.334 and 0.224, respectively) and good stability (zeta potential values of -10.8 and -14.6 mV, respectively). Silver nanoparticles showed stronger antibacterial, antifungal, and antimitotic effects than the bark extracts used for their synthesis. Silver nanoparticles obtained in the present study are promising candidates for the development of novel formulations with various therapeutic applications.

Synthesis and Structural Characterization of Some 1,3-Dithiol-2-ylium Salts

A new series of 2-(dialkylamino)-1,3-dithiol-2-ylium cations derived from acetophenones and propiophenones was synthesized by the intramolecular condensation of appropriate substituted dithiocarbamates. The structural characterization of the new compounds has been performed by NMR and IR analysis. The structure of 1,3-dithiol-2-ylium perchlorate 3e has been proved by X-Ray analysis.

Study of Physico-chemical Characteristics and Pharmacological Effects of 1-Ethyl-Salicyldene-bis-Ethylene-Diamine and Its Complex with Mn(II)

The paper presents the synthesis of a new complex combination of a Bis-Schiff base with Mn(II) ions with great potential for antimicrobial and anti-inflammatory activity. A new complex of the Salen-type ligand, 1-ethyl-salicylidene-bis-ethylene diamine was synthetized using Mn(II) ions. The chemical structure was confirmed through 1H-NMR and IR spectroscopy. The antimicrobial activities of the Bis-Schiff base and its complex were tested in comparison with Ampicillin, Chloramphenicol, Tetracycline, Ofloxacin and Nystatin. Those compounds were found to be active against Gram-positive or Gram-negative bacteria, and had an anti-inflammatory effect comparable to that of Indomethacin.

Reversed-Phase High Performance Liquid Chromatographic Analysis of Three First Line Anti-Tuberculosis Drugs

Active pharmaceutical ingredients such as isoniazid, pyrazinamide and rifampicin are among the most important first-line anti-tuberculosis drugs. A simple, rapid and sensitive reversed phase-high performance liquid chromatographic assay method for the simultaneous determination of isoniazid, pyrazinamide and rifampicin has been developed. Separation of the interest compounds was achieved in a 10 min chromatographic run in gradient elution mode on a Zorbax SB-C18 stainless steel column (150 � 4 mm, 5 mm) using a guard column containing the same stationary phase. The gradient elution was carried out with a mobile phase of 10% CH3CN aqueous solution for channel A and 50% CH3CN in pH = 6.8 phosphate buffer (20 mM), to which 1.5 mL triethylamine were added for channel B. Quantification of the analyzed substances was carried out spectrophotometrically at 269 nm. Detection limits of 0.48 mg/L for isoniazid, 0.52 mg/L for pyrazinamide and 0.48 mg/L for rifampicin were established for the developed assay method. The present work showed that the proposed analysis method was advantageous for simple and rapid analysis of the active pharmaceutical ingredients in pharmaceuticals and biological fluids.

Aniline Derived Bis-Schiff Base - Analytical Reagent for the Assay of Fe (III)

A new spectrophotometric method for the quantitative determination of Fe (III) was established based on the complexation reaction with a new bis-Schiff base, 4,4`-methylenebis-salicylidene aniline, when a stable complex with an absorption maximum at 520 nm was obtained. The conditions of the complexation reaction were established and the method was validated according to ICH guidelines in terms of linearity, accuracy, precision of the method and the limits of detection and quantification were determined. The method was applied with good results for the quantitative determination of Fe (III) in pharmaceutical products.

Studies on Chromatographic Fractioning by Cations Exchangers of a Bovine Hemoglobin Hydrolysate

A peptidic hydrolysate has been obtained through hydrolysis of bovine hemoglobin using pepsin. The fractioning of the hydrolysate was performed on a column packed with CM-Sepharose Fast Flow. The hydrolysate and each fraction was filtered and then injected into a HPLC system equipped with a Vydak C4 reverse phase column (0.46 x 25 cm), suitable for the chromatographic separation of large peptides with 20 to 30 amino acids. The detection was done using mass spectrometry, and the retention time, size and distribution of the peptides were determined.

Validation and Application of an Analysis Method of Four Metabolites of Nitrofurans in Honey

Although nitrofurans are supposed to be absent in foods, they are still used in veterinary medicine for the treatment of infections in animals not bred for consumption. That meant that there are still samples of honey contaminated with residues of nitrofurans because of bees treated with those pharmaceutical substances. Developing accessible methods to detect them is of high interest to food residue monitoring and regulation programs. We propose an immunochemical method as an alternative to detect four toxic metabolites of nitrofurans (1-aminoimidazolidine-2,4-dione, 3-amino-5-morpholinomethyl-2-oxazolidinone, 3-amino-2-oxazolidone and semicarbazide) in honey. The new method has been optimized and validate for the simultaneous determination of the four metabolites of the nitrofurans honey using biochip technology, and it has been used for the quantitative determination of the residues in 16 Romanian honey samples. The evaluated validation parameters included: linearity, sensitivity (IC50 �2.32 mg/kg), specificity and selectivity, precision (intermediate and reproducibility) and accuracy, decision limit (CCa between 0.37 and 1.05 mg/kg), detection capability (CCb between 0.42 and 1.14 mg/kg), and recovery coefficient (64�192%).

Study of the Presence of Lead in a Series of Foods of Plant Origin

The objective of the study was to evaluate the presence of lead in several food products of plant origin. An atomic absorption spectroscopic quantitative method for the analysis of Pb+2 was developed and validated using an Analytik Jena ContrAA 300 apparatus equipped with an air-acetylene flame and a high-resolution continuum source. The analyzed food products were wheat, wheat flour, onions, corn, corn flour, carrots, beans, potatoes and cabbage grown in three geographical areas, on three soil types. The results obtained were in line with the limits laid down in Commission Regulation (EC) No 1881/2006 - Consolidated acts as far as the maximum admissible level of Pb+2 in foods.

Parameters of Chemical Composition of Phaseolus coccineus L. Pods Grown in Protected Areas

Runner beans are an important source of carbohydrates, fibers, vitamins and minerals that play an important part in the cardiovascular and gastrointestinal tract physiology. The aim of the study was the identification of crop specificities of four varieties of Phaseolus coccineus L. homologated in the Great Britain: Lady Di, Desiree, Polestar and White Apollo, which are less cultivated in Romania, although during the study they proved a remarkable crop production. Another objective of the study was the determination of some chemical composition parameters of the pods harvested from protected areas, in order to highlight the particularities that could determine the expansion of their cultivation in our country.

Influence of Hydroxypropyl Methylcellulose on Flowing and Swelling Parameters in Biomucoadhesive Tablets with Miconazole Nitrate

Original pharmaceutical formulations have been produced as oral biomucoadhesive tablets for antifungal medication. They have been obtained through direct compression using as matrix forming polymers various sorts of hydroxypropyl methylcellulose. The main goal of the study was determining the swelling index of the new mucobioadhesive formulations with miconazole nitrate in order to correctly evaluate the time of contact with mucosa, and the prolongation of drug release. For each formulation, the flowing parameters have been determined: flowing time, friction coefficient, repose angle, Haussner ratio, Carr index, and the swelling index for 6 formulations containing various sorts of hydroxypropyl methylcellulose as matrix molders, while the formulation variables studied were time and association ratio between those polymers. Though results analysis, we noticed that the values of the swelling index depended on the type and quantity of polymer, results that could also be explained by the proportionality relationship to flowing and compressibility parameters.

Fast HPLC Method for the Determination of Piroxicam and its Application to Stability Study

A fast and robust RP-HPLC isocratic method was developed for determination of piroxicam in bulk materials and pharmaceutical formulations. Optimum separation of piroxicam and stress induced degradation a product was achieved using a SB-C18 Eclipse column (150x4.6; 5�m). The mobile phase was a mixture of water: acetonitrile (50:50) with a flow rate of 0.5mL/min. The UV detection was performed at 360nm. The method was validated in accordance with the current ICH guidelines in terms of linearity, limit of detection, limit of quantification, precision, accuracy, recovery and system suitability. The retention time for piroxicam was 2.55 min. The calibration graph was linear in the concentration range 5-90�g/mL. The assay proved to be sensitive, specific and reproducible. The method was applied for the determination of piroxicam in tablets.

Evaluation of in Vitro Reducing Effect of Several Vegetable Extracts on the Digestive Bioavailability of Heavy Metals

The study aimed at assessing the in vitro digestive bioavailability of heavy metals in the presence of plant extracts under simulated digestive system conditions. The complexing ability of aqueous herbal extracts of Crataegus sp., Tilia spp., Rosa canina, Vaccinium myrtillus, Geranium robertianum, Mentha piperita, Cynara cardunculus subsp. Scolymus, Plantago sp., and Coriandrum sativum was researched on Cu+2, Cd+2, Ni+2, Pb+2 and Hg+2 cations. The quantitative determination of the fraction of free metal left, available for absorption, was achieved by atomic absorption spectroscopy (AAS) or potentiometry using an ion-selective electrode (ISE).

Synthesis and Biological Evaluation of a New Schiff Base and its Cu(II) Complex

A new Schiff base ligand, N-hydroxy-N�-salicylidene-urea was synthesized through the condensation of salicylaldehyde with hydroxyurea. The copper(II) complex of the Schiff base has been also obtained. Their structure has been proven using spectral methods such as UV-Vis, FT-IR, 1H-NMR and elemental analysis. The antimicrobial activity of the copper(II) complex was evaluated through comparison to the activity of the Schiff base on various bacterial strains. All tested compounds were very active against both gram-positive and gram-negative bacteria.

Novel Multiresidue Method for the Determination of Eight Trichothecene Mycotoxins in Pollen Samples Using QuEChERS-Based GC-MS/MS

A simple multi-residue method based on QuEChERS-sample preparation was developed for the determination of eight trichothecene mycotoxins (nivalenol, fusarenon-x, diacetoxyscirpenol, 3-acetyl-deoxynivalenol, neosolaniol, deoxynivalenol, T-2 and HT-2 toxins) in pollen, using gas chromatography coupled with mass spectrometry. The developed method was validated by evaluating the following parameters: linearity, limit of quantification, matrix effect and precision of measurements. All mycotoxins showed good linearity. The method gave good recoveries (91-104%) with RSDs ] 11% for most of the analites (6 out of 8). The limits of quantification varied from 1 to 4�g�kg--1.

In Vitro Dissolution Studies of Amiodarone Hydrochloride From Hydroxy-Propyl-β-Cyclodextrin/Amiodarone Inclusion Complex Formulated Into Modified-Release Tablets

AIM

Drug release from modified-release matrix tablets made of Kollidon® SR and Chitosan is dependent on its degree of solubility in the dissolution medium as well as on the matrix forming polymer. By complexing hydrochloride amiodarone with hydroxypropyl-β-cyclodextrin, an inclusion complex was obtained, which showed an increase in solubility by more than 200%. The complex was used to obtain modified-release matrix tablets based on Kollidon® SR and Chitosan.

MATERIALS AND METHODS

Matrix tablets were obtained through direct compression method of non-complexed amiodarone and inclusion complex, and they were marked F1 and F10, respectively. The two formulations were studied comparatively in terms of release kinetics of the active substance through in vitro drug release tests. Those tests were conducted using a paddle apparatus II for 12 hours and two gastrointestinal simulation liquids with different pH values relevant for oral administration - 2 hours at pH 1.2 and 10 hours at pH 6.8. The release of hydrochloride amiodarone was quantified using a validated HPLC method. Two factors were calculated to assess the release profile of amiodarone: the similarity factor f1 and difference factor f2.

RESULTS

The increase in Kollidon® SR concentration resulted in a slower release of amiodarone at both pH values. The use of Chitosan resulted in a decrease of AMD release only at pH 6.8.

CONCLUSIONS

The similarities between the two release profiles of AMD were confirmed by the values of the similarity factor (f1 = 43.697) and difference factor f2 (f2 = 68.263).

ANTINFLAMMATORY ACTIVITY OF AN N, N'-DISALICYLIDENEMETHYLENDIAMINE-DERIVED SCHIFF BIS BASE AND ITS COPPER(II) COMPLEX

AIM

The cooper(II) complex combination of N, N'-disalicylidenemethylenediamine and the Schiff bis base were investigated for anti-inflammatory activity.

MATERIAL AND METHODS

In vivo, the anti-inflammatory activity of the metallic complex in comparison with the activity of the Schiff bis base was tested by the method of Winter and co-workers using the Levy technique.

RESULTS AND DISCUSSIONS

Our study on the anti-inflammatory activity of a new Schiff bis base and its complex cooper(II) combination showed that the Schiff bis bases exhibited significant anti-inflammatory action in acute experimental inflammation when compared to the control group. The copper cation from the complex combination enhanced the anti-inflammatory effect of the Schiff bis base, the effect being stronger at doses of 10 mg/kg cooper(II) complex.

CONCLUSIONS

The Schiff bis base and its cooper(II) complex had an anti-inflammatory effect comparable to that of indomethacin.

OPTIMIZATION OF THE PREPARATION OF KOLLIDON SR-BASED AMIODARONE HYDROCHLORIDE TABLETS WITH SUSTAINED RELEASE

AIM

The formulation of sustained release tablets of AMD-HCl using KOLLIDON SR as matrix-forming agent. Chitosan, a natural polysaccharide with superior hydrating and absorbing properties was used in the formulation stage to optimize the release characteristics of those matrix tablets.

MATERIAL AND METHODS

Nine formulations of sustained release matrix tablets of AMD x HCl (200 mg/tablet) were prepared through direct compression. The concentrations of matrix forming agents were included as independent variables of a type 2(3) mixed factorial plan in order to develop formulations of AMD-HCl with optimal release characteristics. The dependent variables of that plan were the amount of AMD released from the tablets studied by using in vitro dissolution testing. The test was carried out in the paddle apparatus II for 12 hours in two pH media that were relevant to oral delivery: 2 hours at pH 1.2 and 10 hours at pH 6.8. The released AMD-HCl was quantitatively determined through a validated HPLC method.

RESULTS

The increase in KOL concentration leads to a decrease in AMD release rate at both pH values. The use of CHT resulted in a decrease of AMD release only at pH 6.8 in formulations with the lowest concentration of KOL.

CONCLUSIONS

The retarding effect on the release of AMD-HCl in the tablets developed in this study was directly proportional to the KOL concentration in the formulation.

A NEW SPECTROPHOTOMETRIC METHOD FOR THE ASSAY OF LISINOPRIL

AIM

A new spectrophotometric method for the assay of lisinopril using 2,4-dinitrophenol as reagent is described.

MATERIAL AND METHODS

The method involved the addition of 2,4-dinitrophenol to lisinopril in methanol followed by absorbance measurement at 400 nm. Experimental conditions that provide wide linear range, maximum sensitivity, selectivity, accuracy and precisions were optimized.

RESULTS AND DISCUSSIONS

Beer's law was obeyed in the concentration range 2.0-14.0 μg/mL. Linear regression equation of calibration graph was A = 0.005 + 0.045 x concentration, with a regression coefficient (r) of 0.9995 (n = 8). The limits of detection (LOD) and quantification (LOQ) calculated according to the ICH guidelines were 0.42 and 1.42 μg/mL, respectively. Accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different lisinopril concentrations; the intra-day and inter-day RSD was < 1.43% and accuracy was better than 1.72%.

CONCLUSIONS

The proposed method is simple, easy to perform, sensitive, linear, precise, accurate and robust.

IN VITRO TESTING OF XANTHAN/LIGNIN HYDROGELS AS CARRIERS FOR CONTROLLED DELIVERY OF BISOPROLOL FUMARATE

AIM

To develop sustained release matrix tablets based on xanthan as highly water-soluble, cost-effective, non-toxic, easily available, and suitable hydrophilic systems.

MATERIAL AND METHODS

Xanthan and lignin epoxy-modified resin (LER) mixture were crosslinked using epichlorohydrin as crosslinking agent leading to superabsorbent hydrogels with high swelling rate in aqueous mediums.

RESULTS AND CONCLUSIONS

These hydrogels were tested as carries by the loading/delivery behaviour of bisoprolol fumarate in physiological conditions and based on the obtained results these hydrogels may show interest for application in medical and pharmaceutical areas. The amount of drug loaded in polymer networks was found to be ranging between 14.4% and 19.2%. Drug release was retarded and the release mechanism of the active principle was found to depend on matrix composition.

Spectrophotometric method for estimation of bisoprolol fumarate in tablets

Bisoprolol fumarate is prescribed for the treatment of hypertension and angina pectoris.

AIM

The purpose of this study was to develop a simple, sensitive, accurate, and reproducible method for estimation of bisoprolol fumarate in tablets.

MATERIAL AND METHODS

The proposed method was based on a yellow colored complex formed with tropaeolin 00, extractable in dichloromethane with maximum absorbance at 412 nm. The method was validated statistically.

RESULTS

The linearity domain was observed in the concentration of 5-30 microg/ml. The recovery studies confirmed the accuracy of the proposed method.

CONCLUSIONS

The proposed method can be applied for the routine analysis of bisoprolol from formulations.

Spectrometric method for the assay of ramipril using molybdophosphoric acid

Ramipril is a drug of the angiotensin converting enzyme inhibitor class.

AIM

A new molecular absorbance spectrometric method was developed for the assay of ramipril using molybdophosphoric acid in acidic medium.

MATERIAL AND METHODS

The reaction product showed a maximum absorbance at 361 nm. The optimum conditions of the reaction were established. The developed method was validated.

RESULTS

The method showed a good linearity in the range of 8 - 36 microg/ml (correlation coefficient r = 0.9996). The detection limit (LD) was 0.86microg/ml and the quantification limit (LQ) 2.88 pg/ml. Precision and accuracy were determined (RSD = 1.15%); mean recovery was 98.90% in the 97.13-101.03% concentration range.

CONCLUSIONS

The proposed method is simple, easy to perform, sensitive, linear, precise, accurate and robust.