8 research outputs found
Pharmacokinetics of diclofenac sodium and papaverine hydrochloride after oral administration of tablets to rabbits
Non-compartmental pharmacokinetic analysis of diclofenac sodium (DIC) and papaverine
hydrochloride (PAP) after oral administration of composed tablets to rabbits was developed. HPLC method for determination of DIC and PAP in rabbit plasma was developed and validated. Chromatographic separation of DIC, PAP and the IS was achieved on a Zorbax SB C18 5-μm column (150 mm ◊ 4.6 mm) using methanolwater (55 : 45, v/v) as mobile phase at a flow rate of 0.8 mL/min. Pharmacokinetic analysis showed that oral administration of a tablet composed of DIC and PAP do not change the pharmacokinetic parameters such as MRT, MAT, Cl and bioavailability of the active substances compared with single administration of DIC and PAP after single dose
Bioaccessibility of phenolic compounds, lutein, and bioelements of preparations containing Chlorella vulgaris in artificial digestive juices
Chlorella vulgaris Beijerinck is a spherical, green alga belonging to the genus Chlorella and family Chlorellaceae. It has high
nutritional value and shows multiple biological effects. Dietary supplements that contain extracts of C. vulgaris are sold in the
form of tablets, capsules, powders, and aqueous solutions. To the best of our knowledge, this is the first study to determine the
content of bioelements (zinc, iron, and magnesium), phenolic compounds, and lutein before and after incubation with artificial
digestive juices from preparations containing C. vulgaris. In this study, we used commercial preparations in the form of powder
and tablets. The samples were incubated in artificial gastric juice and then in artificial intestinal juice for 30 and 90 min. The
contents of bioelements were determined by using the flame atomic absorption spectrometric method. Lutein and phenolic
compounds were analyzed by high-pressure liquid chromatography. We also aimed to evaluate the quality of chlorellacontaining
formulations by using the methods described in the European Pharmacopoeia 8th edition. According to the results,
the preparations containing C. vulgaris demonstrated the presence of phenolic compounds and lutein. Therefore, daily supplementation
of preparations containing C. vulgaris substantiates its usefulness for humans. The qualitative composition of the
examined organic substances and bioelements was found to be in accordance with the manufacturer's declarations on the
packaging containing C. vulgaris compared with the control samples; however, the contents of bioelements were found to be
negligible after incubation with artificial digestive juices. This shows that the examined preparations containing C. vulgaris are
not good sources of bioelements such as zinc, iron, or magnesium
Release of bioactive substances from formulations containing "Arthrospira Platensis (Spirulina Platensis)"
Arthrospira platensis (Spirulina platensis) is a well-known microalga and has been utilized as a
medicinal agent and foodstuff by humans since at least 16th century. The aim o f this study was to determine zinc content as well as determine phenolic and indole compounds from commercial preparations containing Arthrospira platensis (lyophilizate, tablets, and capsules) before and after extraction with methanol and incubation with artificial digestive juices. The secondary aim of this study was to evaluate the quality of these preparations. The samples were incubated in artificial stomach juice and in intestinal juice. The samples were mineralized and their zinc(II) ions content was estimated using flame absorption atomic spectroscopy (F-AAS). The maximum zinc(II) ions content released into the digestive juices was found to be up to 1.6 mg/100 g of the preparation. Phenolic compounds identified in the examined extracts are as follows: gallic acid; protocatechuic acid; 3,4-dihydroxyphenylacetic acid; p-hydroxybenzoic acid; syringic acid; cinnamic acid; and quercetin. Furthermore, indole compounds identified were 5-hydroxy-L-tryptophan, 5-methyl-L-tryptophan, L-tryptophan, tryptamine, and 5-methyltryptamine. Consequently, it was also found that the distributed Arthrospira platensis in the form of tablets does not disintegrate in the artificial digestive juices. Among the examined preparations, only hard capsules met the requirements of the European Pharmacopeia 8th ed
Release Kinetics of Papaverine Hydrochloride from Tablets with Different Excipients
The influence of excipients on the disintegration times of tablets and the release of papaverine hydrochloride (PAP) from tablets were studied. Ten different formulations of tablets with PAP were prepared by direct powder compression. Different binders, disintegrants, fillers, and lubricants were used as excipients. The release of PAP was carried out in the paddle apparatus using 0.1 N HCl as a dissolution medium. The results of the disintegration times of tablets showed that six formulations can be classified as fast dissolving tablets (FDT). FDT formulations contained Avicel PH 101, Avicel PH 102, mannitol, β-lactose, PVP K 10, gelatinized starch (CPharmGel), Prosolv Easy Tab, Prosolv SMCC 90, magnesium stearate, and the addition of disintegrants such as AcDiSol and Kollidon CL. Drug release kinetics were estimated by the zero- and first-order, Higuchi release rate, and Korsmeyer-Peppas models. Two formulations of the tablets containing PVP (K10) (10%), CPharmGel (10% and 25%), and Prosolv Easy Tab (44% and 60%) without the addition of a disintegrant were well-fitted to the kinetics models such as the Higuchi and zero-order, which are suitable for controlled- or sustained-release
Immunosensor Based on Long-Period Fiber Gratings for Detection of Viruses Causing Gastroenteritis
Since the norovirus is the main cause of acute gastroenteritis all over the world, its fast detection is crucial in medical diagnostics. In this work, a rapid, sensitive, and selective optical fiber biosensor for the detection of norovirus virus-like particles (VLPs) is reported. The sensor is based on highly sensitive long-period fiber gratings (LPFGs) coated with antibodies against the main coat protein of the norovirus. Several modification methods were verified to obtain reliable immobilization of protein receptors on the LPFG surface. We were able to detect 1 ng/mL norovirus VLPs in a 40-min assay in a label-free manner. Thanks to the application of an optical fiber as the sensor, there is a possibility to increase the user’s safety by separating the measurement point from the signal processing setup. Moreover, our sensor is small and light, and the proposed assay is straightforward. The designed LPFG-based biosensor could be applied in both fast norovirus detection and in vaccine testing
Toward a pulsed antihydrogen beam for WEP tests in AEgIS
The AEg̅IS collaboration at CERN’s AD produces antihydrogen atoms in the form of a pulsed, isotropic source with a precisely defined formation time. AEg̅IS has recently undergone major upgrades to fully benefit from the increased number of colder antiprotons provided by the new ELENA decelerator and to move toward forming a horizontal beam to directly investigate the influence of gravity on the H̅ atoms, thereby probing the Weak Equivalence Principle for antimatter. This contribution gives an overview of these upgrades as well as subsequent results from the first beam times with ELENA
Constraints on the Galactic Halo Dark Matter from Fermi-LAT Diffuse Measurements
We have performed an analysis of the diffuse gamma-ray emission with the
Fermi Large Area Telescope in the Milky Way Halo region searching for a signal
from dark matter annihilation or decay. In the absence of a robust dark matter
signal, constraints are presented. We consider both gamma rays produced
directly in the dark matter annihilation/decay and produced by inverse Compton
scattering of the e+e- produced in the annihilation/decay. Conservative limits
are derived requiring that the dark matter signal does not exceed the observed
diffuse gamma-ray emission. A second set of more stringent limits is derived
based on modeling the foreground astrophysical diffuse emission using the
GALPROP code. Uncertainties in the height of the diffusive cosmic-ray halo, the
distribution of the cosmic-ray sources in the Galaxy, the index of the
injection cosmic-ray electron spectrum and the column density of the
interstellar gas are taken into account using a profile likelihood formalism,
while the parameters governing the cosmic-ray propagation have been derived
from fits to local cosmic-ray data. The resulting limits impact the range of
particle masses over which dark matter thermal production in the early Universe
is possible, and challenge the interpretation of the PAMELA/Fermi-LAT cosmic
ray anomalies as annihilation of dark matter.Comment: 23 pages, 7 figures, 3 tables. Contact authors: Jan Conrad,
Alessandro Cuoco, Zhaoyu Yang, Gabrijela Zaharijas; v2: matches version
published on Ap