الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The present thesis comprises three chapters:
Chapter (1l
Contains the introduction which includes two parts : the first
part gives an idea about the drugs under consideration, a discussion
about the definitions, actions, chemical structures and chemical
names, characters of the studied drugs ( Norfloxacin, Ciprofloxacin.
and Ofloxacin ) are also given. The second part involves a literature
survey of the previous studies for the analysis of the studied drugs
including spectrophotometric, UVNis spectrophotometric, capillary
electrophoresis, high performance liquid chromatography (HPLC),
electroanalytical and chromatographic methods, and oscillopolarographic
titration methods. Chemical structures, chemical names and a
literature survey of the acid dyes used Calcon carboxylic acid (Calc.),
Eriochromeblack T (EST) and Alizarin red S (Aliz.) .
Chapterf1}
Contains the experimental part which includes apparatus used for
measurement, procedures for preparation of the drug solutions reagents
and methods of some companies taken from different pharmacopoeia for
determination of the studied drugs in pure forms or in the pharmaceutical
forms which are analysed. It also contains the proposed
spectrophotometric methods for determination of the drugs under
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considerations in pure forms and in dosage forms. Also, it contains the
official methods for analysis of the studied drugs.
ChapterQ),
Contains the results and discussion which include the
spectrophotometric procedures for determination of the studied drugs
using acid dyes reagents Calcon carboxylic acid (Calc.), Eriochromeblack
T (EST) and Alizarin red S (Aliz.) .
The proposed methods are based on coloured ion pair complex
formation between the acid dyes and drugs which is extracted with an
organic solvent (chloroform) in case of Eriochromeblack T (EST), Alizarin
red S (Aliz.) and Calconcarboxylic acid (Calc.), and determination of the
concentration by measuring the absorbance of the extracted complex
after dilution in acetone against a blank (acetone). The following
experimental variables were investigated.
1 - Effect of pH.
2- Effect of shaking time.
3- Effect of the polarity of extracting solvent.
4- Effect of reagent concentration.
5..,Molar ratio of the complex.
6- Suggested mechanism.
7-lnterference.
8- Evaluation of the stability constants of the ion-pair complexes .
1- Using Calc.
Beer’s law is obeyed within the-concentration ranges (O.033 - 3.3
J,.Ig/ml)for norfloxacin , ciprofloxacin and ofloxacin in case of Calconcarbo.
xylic acid (Calc.), For more accurate results, t,.he Ringbom optimum - 157,-
-’ - .._’ --
concentration ranges were determined Molar absorptivity, Sandell
sensitivity, detection and quantification limits are calculated. The
stoichiometric ratios of the studied drugs with Calconcarboxylic acid
(Calc.), are established using the mole ratio and continuous variation
methods and was found to be 1: 1 ratio for all the drugs under
consideration with Calc. In order to determine the accuracy and precision
of the studied drugs sample solutions containing three different
concentrations were prepared and analysed in six replicates. The
recovery, relative standard deviation, relative error and confidence limits
are calculated
The proposed methods can successfully be applied to determine the pure
form of the studied drugs and in their dosage forms. The results obtained
are compared statistically by student’s t-value and variance ratio F-test
with the official methods at 95% confidence level. The results showed
that the t- and F-values are less than the critical value indicating that
there is no significant difference between the proposed and official
methods. Thus, the proposed spectrophotometric methods can be
applied for the determination of the studied drugs in pure and dosage
forms. Also the studied drugs were determined in urine samples and the
results showed that no interferences occur between the studied drugs
and urine can occur.
2- Using EBT
Beer’s law is obeyed in the concentration ranges (O~11 -2.65
IJg/ml) for norfloxacin , ciprofloxacin and ofloxacin in case of
Eriochromeblack T (EST), For more accurate results, the Ringbom
optimum concentration ranges are determined. Molar absorptivity,
Sandell sensitivity, detection and quantification limits were calculated.
The stoichiometric ratios of the studied drugs with (EST) are established
using the mole ratio and continuous variation methods and found to be
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1:1 ratio for all the drugs under consideration with (EST), In order to
determine the accuracy and precision of the proposed methods, solutions
containing three different concentrations of the studied drugs are
prepared and analysed in six replicates. The recovery, relative standard
deviation, relative error and confidence limits are calculated.
The proposed methods can be successfully applied to determine the pure
form of the studied drugs and in their dosage forms. The results obtained
are compared statistically by student’s t-value and variance ratio F-test
with the official methods at 95% confidence level. The results showed
that the t- and F-values are less than the critical value indicating that
there is no significant difference between the proposed and official
methods. Thus, the proposed spectrophotometric methods can be
applied for the determination of the studied drugs in pure and dosage
forms. Also the studied drugs were determined in urine samples and the
results showed that no interferences occur between the studied drugs
and urine can occur.
3- Using Aliz.
Beer’s law is obeyed in the concentration ranges (0.17 -3.3
IJg/ml) for norfloxacin, for ciprofloxacin and ofloxacin in case of Alizarin
red S (Aliz.), for more accurate results, the Ringbom optimum
concentration ranges were determined. Molar absorptivity, Sandell
sensitivity, detection and quantification limits are calculated. The
stoichiometric ratios of the studied drugs with (Aliz.) are established using
the mole ratio and continuous variation methods and found to be 1:1 ratio
for all the drugs under consideration with (Aliz.). In order to determine the
accuracy and precision of the proposed methods, solutions containing
three different concentrations of the studied drugs were prepared and
analysed in six replicates. The recovery, relative standard deviation,
relative error and confidence i:mits are calculated. The proposed
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methods can be successfully used to determine the pure and dosage
forms of the studied drugs. The results obtained are compared
statistically by student’s t value and variance ratio F-test with the official
methods at 950/0 confidence level. The results showed that the t- and
F-values are less than the critical value indicating that there is no
significant difference between the proposed and official methods. Thus,
the proposed spectrophotometric, methods can be applied for the
determination of the studied drugs in pure and in dosage forms. In
addition, the studied drugs were determined in urine samples and the
results showed that no interferences between the studied drugs and urine
could occur.
4- Type of formed complex
Formation of some sort of ion pairs between the anion of one
component and the cation of the other leads to appearance of new
bands, attributed to the occurrence of a charge transfer between the two
components of the ion pair .this appear from the ionization potentials of
the two components of the ion pair (CT complex), and to confirm this
point, energy of charge transfer and electron affinity are calculated.
5- IR support
from IR spectra of the solid complexes in comparison to those
of their components, we find that:-
1- YCH bands of the donor shifted to higher wave number and the other
of the acceptor shifted to lower wave number.
2- C=O bands of the CT formed complexes shifted to lower wave
number than that of drugs.
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This reflects that the charge transfer interaction are from the
reagent to the drug molecule and the donor center is
1- hydroxynaphthyl moiety of E.B.T.
2- benzene ring carrying the two hpiroxyl group of Aliz.
3- Hydroxycarboxynaphthyl moiety of Calcon.
Acceptor center is
4- benzquinolone moiety of acceptor drugs
6- ESR support
” The ESR spectra of the ion pair complexes gave obvious signals
with geff at (2.149) and (1.9616). The signal has a rather broad
appearance with doubled peaks, a behavior which is very identical to the
ESR spectra of charge transfer complexes involving n -t n*charge
transfer interaction.