scholarly journals In vitro study on the interaction of ketotifen fumarate with anhydrous theophylline

2012 ◽  
Vol 48 (2) ◽  
pp. 211-216
Author(s):  
Mohammed Aktar Sayeed ◽  
Razibul Habib ◽  
Mominur Rahman ◽  
Hasan Al Banna ◽  
Sohel Rana
Keyword(s):  
Stability Constants ◽  
Aqueous Media ◽  
In Vitro Study ◽  
Stable Complex ◽  
Concurrent Administration ◽  
Fixed Temperature ◽  
Ketotifen Fumarate ◽  
The Stability ◽  
Anhydrous Theophylline

The purpose of the present study was to investigate the interaction between ketotifen fumarate and anhydrous theophylline in aqueous media of various pH (1.2 and 6.8). Using Job's continuous-variation analysis and Ardon's spectrophotomeric measurement methods, the values of the stability constants of theophylline with ketotifen were determined at a fixed temperature (37 ºC) at various pH. The stability constants, ranging between 5.66 and 9.92, were derived from Ardon's plot, indicating that comparatively stable complexes had formed as a result of an interaction between the drugs. However, following the interaction of theophylline with ketotifen, stability constants were <1 at gastric pH (1.2) and intestinal pH (6.8). Concurrent administration of ketotifen and theophylline could result in the formation of a stable complex and this is likely to reduce the therapeutic activities of both drugs.

scholarly journals In vitro Study on Interaction of Ketotifen Fumerate with Paracetamol

IIUC Studies ◽  
2012 ◽  
Vol 7 ◽  
pp. 49-54
Author(s):  
Mohammed Aktar Sayeed ◽  
Sohel Rana
Keyword(s):  
Stability Constants ◽  
Aqueous Media ◽  
In Vitro Study ◽  
Vitro Study ◽  
Reaction Systems ◽  
The Stability

Interaction of ketotifen fumerate and paracetamol was studied in aqueous media. The ability of interaction of ketotifen with paracetamol is dependent on pH of the solution and it has been found that ketotifen forms 1:1 complexes at different pH. The stability constants have been calculated from the Ardon’s spectrophotomeric measurements of the reaction systems. When ketotifen was interacted with paracetamol and the absorbance was determined at 300 nm the stability constants were found of - 7.32 and -7.84 at pH 1.6 and 7.4 respectively. DOI: http://dx.doi.org/10.3329/iiucs.v7i0.12258 IIUC Studies Vol.7 2011: 49-54

scholarly journals In vitro Interaction of Metronidazole and Mebendazole with Copper (II) and Chromium (III) in Aqueous Media

2011 ◽  
Vol 4 (1) ◽  
pp. 173 ◽  
Author(s):  
A. T. M. Z. Azam ◽  
F. Siraji ◽  
M. S. Amran ◽  
J. N. Islam ◽  
F. M. Amjad ◽  
...  
Keyword(s):  
Spectroscopic Method ◽  
Aqueous Media ◽  
Conductometric Titration ◽  
Spectral Studies ◽  
Stable Complex ◽  
Fixed Temperature ◽  
Molar Ratios ◽  
Spectrophotometric Methods ◽  
Ph Values

The interaction of metronidazole, an antiprotozoal agent and mebendazole, an important anthelmentic agent with Cu (II) and Cr(III) ions have been studied in aqueous systems at a fixed temperature of 37±0.5°C  and at different pH values. It has been found that metronidazole and mebendazole form stable 1:1 complexes with Cu(II), but a less stable complex with Cr(III) ion.  The studies were performed by electroanalytical and spectrophotometric methods. Spectral studies helped to detect initial complexation between the species. Conductometric titration indicated the nature of interaction and the stoichiometries of complexation. The conductometric study also indicated the formation of complexes of various molar ratios viz 1:2, 4:1, 3:1, 1:2, 1:3 and 1:4. etc. along with 1:1 complexes at various pH conditions. Similar types of complexation were observed by Job’s plots at various pH values. The Ardon’s spectroscopic method confirmed the 1:1 complexation and the values of stability constant were calculated using Ardon’s plot. Complexation at molar ratios 1:3 and 1:4 can not be ruled out. Keywords:  Metronidazole; Mebendazole; Cu(II); Cr(III); Ardon’s plot; Complexation. © 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v4i1.7599J. Sci. Res. 4 (1), 173-181 (2012)

Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

2020 ◽  
Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Dynamic Loading ◽  
Antibacterial Agent ◽  
In Vitro Study ◽  
Control Group ◽  
Silicone Sealant ◽  
Reverse Torque ◽  
The Stability ◽  
Torque Values ◽  
Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

In vitro Study on the Interaction of Caffeine with Gliclazide and Metformin in the Aqueous Media

2009 ◽  
Vol 4 (5) ◽  
pp. 194-204 ◽  
Author(s):  
Mohammad Mohiuddin ◽  
A.T.M. Zafrul Azam ◽  
Md. Shah Amran ◽  
Md. Amjad Hossain
Keyword(s):  
Aqueous Media ◽  
In Vitro Study ◽  
Vitro Study

Discontinuous spectrocolorimetric titration method for determining stability constants of fulvic acid - iron complexes

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1279 ◽  
Author(s):  
S. B. Pandeya ◽  
A. K. Singh
Keyword(s):  
Stability Constant ◽  
Stability Constants ◽  
Aqueous Media ◽  
Poultry Manure ◽  
Fulvic Acids ◽  
Titration Method ◽  
Binding Ability ◽  
Press Mud ◽  
Determining Factors ◽  
The Stability

The stability constants for the complexes formed between iron species existing in ambient soil environment and fulvic acids (FA) extracted from organic wastes like sewage sludge, farm yard manure (FYM), poultry manure, and press mud were determined in aqueous media of pH 5·0 and 8·5 by discontinuous spectrocolorimetric titration method. The values of stability constant (log K) of Fe–FA complexes estimated at pH 5·0 were 6·026, 6·212, 6·270, and 6·342 for FYM, sludge, poultry manure, and press mud, respectively. The respective values at pH 8·5 were 6·145, 6·276, 6·350, and 6·940. The order of the values of log K for different preparations of fulvic acids was press mud > poultry manure > sludge > FYM. The functional group contents, their pH of neutralisation, and electrostatic properties of the FA such as pKINT, pKm, and 0·868 nW, were found to be the determining factors for maximum binding ability of FA for metal cations and the stability constant of Fe–FA for different FA preparations. The basic assumptions and the limitations of the discontinuous spectrocolorimetric estimation of stability constants for Fe–FA are discussed.

scholarly journals Influence of Orthodontic Anchor Screw Anchorage Method on the Stability of Artificial Bone: An In Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3205 ◽  
Author(s):  
Seen-Young Kang ◽  
Ji-Min Yu ◽  
Hyoung-Sik Kim ◽  
Jun-Seok Lee ◽  
Chan-Mi Yeon ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Automatic Device ◽  
Insertion Torque ◽  
Artificial Bone ◽  
Artificial Bones ◽  
Significant Difference ◽  
The Mean ◽  
The Stability ◽  
Torque Values

This study aims to compare the torque values for various lengths of the titanium-based orthodontic anchor screw (OAS), different anchorage methods and varying artificial bone densities after predrilling. Furthermore, the effects of these parameters on bone stability are evaluated. A total of 144 OASs were prepared with a diameter of 1.6 mm and heights of 6, 8 and 10 mm. Artificial bones were selected according to their density, corresponding to Grades 50, 40 and 30. Torque values for the automatic device and manual anchorage methods exhibited a statistically significant difference for the same-sized OAS, according to the bone density of the artificial bones (p < 0.05). However, when insertion torque was at the maximum rotations, there was no significant difference in the torque values for the Grade 30 artificial bone (p > 0.05). When the torque values of both anchorage methods were statistically compared with the mean difference for each group, the results of the manual anchorage method were significantly higher than those of the automatic device anchorage method (p < 0.05). A statistically significant difference was observed in the bone stability resulting from different OAS anchorage methods and artificial bone lengths. These findings suggest that the automatic anchorage method should be used when fixing the OAS.

scholarly journals The Stability of Temporary Restorations Fabricated on a Healing Cap for Immediate Loading: An In Vitro Study

2018 ◽  
Vol 8 (11) ◽  
pp. 2261
Author(s):  
Sangho Jun ◽  
Hyonseok Jang ◽  
Enji Cheon ◽  
MinJu Kim ◽  
Sungwon Ju ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Load Distribution ◽  
In Vitro Study ◽  
Bite Force ◽  
Immediate Loading ◽  
Pull Out ◽  
The Stability ◽  
Implant Treatment ◽  
Pull Out Strength

The aim of this study was to analyze the load distribution of interim restorations using healing cap during immediate loading implant treatment in vitro. A total of 29 models with interim restorations which were fabricated with healing cap were selected. The pull-out strength was measured with a used healing cap and new healing cap. The compressive strength and sinking distance were also measured. The pull-out strength of interim restoration showed lower value (max. 29.8 N) compared to the natural bite force. The sinking amounts were larger than normal tooth sinking. The sinking amounts of interim restorations fabricated on a healing cap were roughly 3 times (0.3–0.5 mm under 450 N) those of normal teeth. The interim restoration on plastic healing cap would be useful for immediate loading implant treatment.

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