204 research outputs found
PREPARATION, CHARACTERIZATION AND EVALUATION OF FLOATING MICROPARTICLES OF CIPROFLOXACIN
Objective: The main purpose of this study is to prepare a floating micro articulated drug delivery system of ciprofloxacin by using non-aqueous solvent evaporation technique to increase the bioavailability and therapeutic effectiveness of the drug by prolonging its gastric residence time.Methods: Floating microparticles were prepared by using different low-density polymers such as ethyl cellulose and hydroxypropyl methylcellulose either alone or in combination with the aid of non-aqueous solvent evaporation technique. All the formulated microparticles were subjected to various evaluation parameters such as percentage yield, drug content, drug entrapment, rheological studies, floating characteristics and in vitro drug release studies.Results: Drug-excipient compatibility studies performed with the help of FTIR instrument indicated that there were no interactions. Results revealed that non-aqueous solvent evaporation technique is a suitable technique for the preparation of floating microspheres as most of the formulations were discrete and spherical in shape with a good yield of 65% to 85% and 15 to 22 h of floating duration with 90% of maximum percentage floating capacity shown by formulation FM9. Though, different drug-polymer ratios, as well as a combination of polymers, play a significant role in the variation of overall characteristics of formulations. Based on the data of various evaluation parameters such as particle size analysis, drug content, drug entrapment, rheological studies and in vitro drug release characteristics formulation FM9 was found to fulfil the criteria of ideal floating drug delivery system.Conclusion: Floating microparticles were successfully prepared, and from this study, it can be concluded that the developed floating microspheres of ciprofloxacin can be used for prolonged drug release in the stomach to improve the bioavailability and patient compliance
Mass function and dynamical study of the open clusters Berkeley 24 and Czernik 27
We present a photometric study of the open clusters Berkeley 24 (Be
24) and Czernik 27 (Cz 27). The radii of the clusters are determined as
2\farcm7 and 2\farcm3 for Be 24 and Cz 27, respectively. We use the Gaia Data
Release 2 (GDR2) catalogue to estimate the mean proper motions for the
clusters. We found the mean proper motion of Be 24 as mas
yr and mas yr in right ascension and declination
for Be 24 and mas yr and mas yr for
Cz 27. We used probable cluster members selected from proper motion data for
the estimation of fundamental parameters. We infer reddenings =
mag and mag for the two clusters. Analysis of
extinction curves towards the two clusters show that both have normal
interstellar extinction laws in the optical as well as in the near-IR band.
From the ultraviolet excess measurement, we derive metallicities of [Fe/H]=
dex and dex for the clusters Be 24 and Cz 27,
respectively. The distances, as determined from main sequence fitting, are
kpc and kpc. The comparison of observed CMDs with
isochrones, leads to an age of Gyr and Gyr for
Be 24 and Cz 27, respectively.
In addition to this, we have also studied the mass function and dynamical
state of these two clusters for the first time using probable cluster members.
The mass function is derived after including the corrections for data
incompleteness and field star contamination. Our analysis shows that both
clusters are now dynamically relaxedComment: 16 pages including 8 tables. 22 figures. Accepted by MNRA
Arc-heater performance research
The tasks performed can be divided into the following categories: an analysis of the electric arc phenomena, especially near the electrodes; a parametric study of arcjet performance by means of a computer code (ARCFLO) and verification with experimental data where possible; the development of a data acquisition system to collect the above experimental data using Ames arc-jets; and a study of the critical components (electrodes and constrictor disks) and suggestions of how to improve their performance
Evaluation of Daphnia magna as an indicator of Toxicity and Treatment efficacy of Municipal Sewage Treatment Plant
Performance evaluation of wastewater treatment plants (WWTPs) with special reference to toxicity reduction using Daphnia magna straus as test organism is very important to study the likely adverse effects of thetreated wastewater on the aquatic ecosystem of receiving waters and to detect common environmentally realistic concentrations of pollutants at different concentration levels and toxicity discriminatory ability to distinguish different degree of toxicity and toxic specificity of the compounds on target organisms. This test can be considered asuseful analytical tool for screening of chemical analysis and early warning system to monitor the different operational units of wastewater treatment plants. Interrelationship between COD, SS with respect to Daphnia toxicity (Gd) suggests that improvement of the toxicological quality of wastewater could be linked to the removal of both COD and suspended solids. Both the parameters (COD & SS) can serve as a regulatory tool in lieu of an explicit toxicological standard. An important feature of this work was to emphasize the significance of toxicity tests. It could help to reduceinfluent toxicity and thereby avoid impacting microorganisms’ population in activated sludge systems. This study shows the difference between using physico-chemical and biological criteria to define the quality or toxicity ofwastewater, making it clear that both methods are indispensable and complimentary and support the earlier view that Daphnia magna can serve as a valuable model for bio- monitoring of water pollution and for evaluation of the toxicity of an effluent and risk assessment in an aquatic body, as it is highly sensitive to pollutants
Nonlocal Equation of State in Anisotropic Static Fluid Spheres in General Relativity
We show that it is possible to obtain credible static anisotropic spherically
symmetric matter configurations starting from known density profiles and
satisfying a nonlocal equation of state. These particular types of equation of
state describe, at a given point, the components of the corresponding
energy-momentum tensor not only as a function at that point, but as a
functional throughout the enclosed configuration. To establish the physical
plausibility of the proposed family of solutions satisfying nonlocal equation
of state, we study the constraints imposed by the junction and energy
conditions on these bounded matter distributions.
We also show that it is possible to obtain physically plausible static
anisotropic spherically symmetric matter configurations, having nonlocal
equations of state\textit{,}concerning the particular cases where the radial
pressure vanishes and, other where the tangential pressures vanishes. The later
very particular type of relativistic sphere with vanishing tangential stresses
is inspired by some of the models proposed to describe extremely magnetized
neutron stars (magnetars) during the transverse quantum collapse.Comment: 21 pages, 1 figure, minor changes in the text, references added, two
new solutions studie
The Stability of an Isentropic Model for a Gaseous Relativistic Star
We show that the isentropic subclass of Buchdahl's exact solution for a
gaseous relativistic star is stable and gravitationally bound for all values of
the compactness ratio , where is the total mass and is
the radius of the configuration in geometrized units] in the range, , corresponding to the {\em regular} behaviour of the solution. This
result is in agreement with the expectation and opposite to the earlier claim
found in the literature.Comment: 9 pages (including 1 table); accepted for publication in GR
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