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
and
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
assays, respectively.
and
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.
The modified release of active substances such as chlorzoxazone from matrix tablets, based on Kollidon
SR and chitosan, depends both on the drug solubility in the dissolution medium and on the matrix ...composition. The aim of this study is to obtain some new oral matrix tablet formulations, based on Kollidon
SR and chitosan, in order to optimize the low-dose oral bioavailability of chlorzoxazone, a non-steroidal anti-inflammatory drug of class II Biopharmaceutical Classification System. Nine types of chlorzoxazone matrix tablets were obtained using the direct compression method by varying the components ratio as 1:1, 1:2, and 1:3 chlorzoxazone/excipients, 20-40 w/w % Kollidon
SR, 3-7 w/w % chitosan while the auxiliary substances: Aerosil
1 w/w %, magnesium stearate 0.5 w/w % and Avicel
up to 100 w/w % were kept in constant concentrations. Pharmaco-technical characterization of the tablets included the analysis of flowability and compressibility properties (flow time, friction coefficient, angle of repose, Hausner ratio, and Carr index), and pharmaco-chemical characteristics (such as mass and dose uniformity, thickness, diameter, mechanical strength, friability, softening degree, and in vitro release profiles). Based on the obtained results, only three matrix tablet formulations (F1b, F2b, and F3b, containing 30 w/w % KOL and 5 w/w % CHT, were selected and further tested. These formulations were studied in detail by Fourier-transform infrared spectrometry, X-ray diffraction, thermogravimetry, and differential scanning calorimetry. The three formulations were comparatively studied regarding the release kinetics of active substances using in vitro release testing. The results were analyzed by fitting into four representative mathematical models for the modified-release oral formulations. In vitro kinetic study revealed a complex mechanism of release occurring in two steps of drug release, the first step (0-2 h) and the second (2-36 h). Two factors were calculated to assess the release profile of chlorzoxazone: f1-the similarity factor, and f2-the factor difference. The results have shown that both Kollidon
SR and chitosan may be used as matrix-forming agents when combined with chlorzoxazone. The three formulations showed optima pharmaco-technical properties and in vitro kinetic behavior; therefore, they have tremendous potential to be used in oral pharmaceutical products for the controlled delivery of chlorzoxazone. In vitro dissolution tests revealed a faster drug release for the F2b sample.
In recent years, phytofunctionalized AgNPs have attracted great interest due to their remarkable biological activities. In the present study, AgNPs were synthesized using
and
bark extracts. The ...chemical profile of these bark extracts was analyzed by LC-HRMS/MS. As a first step, the synthesis parameters (pH, AgNO
concentration, ratio of bark extract and AgNO
, 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.
and
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 (IC
= 2.40 ± 0.21 and 6.02 ± 0.61 μg/mL, respectively). The phytosynthesized AgNPs also showed antioxidant and antibacterial effects.
Bisoprolol is a drug belonging to beta blockers drugs used primarily for the treatment of cardiovascular diseases.
A spectrophotometric method for quantitative determination of bisoprolol was ...developed based on the formation of a complex combination between bisoprolol and picric acid.
The complex combination of bisoprolol and picric acid has a maximum absorbance peak at 420 nm. Optimum working conditions were established and the method was validated.
The method presented a good linearity in the concentration range 5-120 microg/ml (regression coefficient r2 = 0.9992). The RSD for the precision of the method was 1.74 and for the intermediate precision 1.43, and recovery values ranged between 98.25-101.48%.
The proposed and validated spectrophotometric method for the determination of bisoprolol is simple and cost effective.
Abstract The present study evaluates the biosynthesis of AgNPs and AuNPs using aqueous and ethanolic Geum urbanum L. rhizome extracts. The biosynthesized metal nanoparticles (MNPs) were characterized ...using UV-Vis spectroscopy, FTIR, DLS, SEM, EDX, and TEM. The UV-Vis spectra confirmed the synthesis of AgNPs and AuNPs through peaks corresponding to the surface plasmon effect of metallic Ag (400–430 nm) and Au (530–570 nm). FTIR analysis indicated that alcohols, phenols, proteins, and carbohydrates from G. urbanum rhizome extracts composition are involved in MNPs synthesis. In DLS analysis, AgNPs (34.26–41.14 nm) showed smaller hydrodynamic diameters than AuNPs (46.26–70.29 nm). At the same time, all values for zeta potential were negative, between − 21 and − 13 mV, suggesting good stabilities for all the colloidal MNPs systems in dispersion. TEM analysis showed that the biosynthesized AgNPs had a spherical morphology, while AuNPs were quasi-spherical, polygonal, and triangular. According to TEM data, AgNPs synthesized using aqueous and ethanolic G. urbanum rhizome extracts were characterized by mean diameters of 9.82 ± 3.68 and 14.29 ± 3.46 nm, while AuNPs by 15.88 ± 6.28 and 24.89 ± 10.75 nm, respectively. EDX analysis confirmed the presence of metallic Ag and Au in the MNPs composition by detecting strong signals at 3 (AgNPs) and 2.2 keW (AuNPs). In disc diffusion assay, MNPs showed good antimicrobial activity against Gram-positive ( S. aureus MSSA, S. aureus MRSA, S. epidermidis ) and Gram-negative ( E. coli, P. aeruginosa, K. pneumoniae ) bacteria and yeasts ( C. albicans ). AgNPs and AuNPs were also characterized by a significant antioxidant potential, evaluated through in vitro assays (lipoxygenase inhibition, DPPH radical scavenging activity, metal ion chelating activity, and hydroxyl radical scavenging assays). An overall better activity was obtained for the ethanolic G. urbanum rhizome extract and its derived AgNPs (EC 50 = 34.2 ± 1.86 mg/mL in lipoxygenase inhibition assay). Therefore, the G. urbanum rhizome extracts proved to be excellent sources for biologically active AgNPs and AuNPs.
For the determination of enalapril maleate in tablets a new, simple and economical HPLC method was developed and fully validated. Chromatographic separation was achieved on Hewlett Zorbax SB-C 18 ...(150 x 4.6 mm, 5 μm) column and the mobile phase consisted of acetonitrile: 0.025 M phosphate buffer adjusted to pH 3 (70:30 v/v) pumped at a flow rate 0.8 mL/min and UV-detection was performed at 210 nm. The proposed method was validated according to ICH guidelines (linearity, limit of detection, limit of quantification, precision, accuracy, recovery and system suitability). The total run time was less than 3 min and the retention time for Enalapril maleate was 2.3 min. The calibration graph was linear in the concentration range between 10 – 100 μg/mL with the correlation coefficient r
= 0.9998. The developed and validated method was successfully applied to determine the Enalapril maleate in tablets. Therefore, this method proved to be sensitive, specific and reproducible and can be applied for routine analysis of enalapril maleate from pharmaceutical formulation due to its simplicity of application.
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