الفهرس 
Chapter IOnly 14 pages are availabe for public view
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Abstract
The thesis comprises five chapters:
Chapter I
This part comprises a short account about the classification and the pharmacological
action of drugs acting mainly on the gastrointestinal tract. This part mainly contains a
general introduction about the chemical names, structures, physical properties,
pharmacological actions and uses of the 8 drugs namely Azintamide, Chlordiazepoxide,
hydrochloride, Cisapride, Drotaverine, Famotidine, Loperamide, Metoclopramide and
Nifuroxazide.
This chapter also introduces some reported literature reviews for the methods used
for the quantitative analysis of these 8 selected drugs in their pharmaceutical preparations
as well as in some biological fluids.
Chapter II
This chapter deals with the development and validation of 2 spectrophotometric
methods for the determination of Nifuroxazide in pure form and in its tablets dosage form.
The first method is based on oxidation of MBTH reagent by ceric ions in acid
medium to form an electrophilic intermediate which is the active coupling species. This
intermediate undergoes electrophilic substitution with Nifuroxazide to produce the
oxidative coupling red product showed maximum absorption at 479 nm.
The second spectrophotometric method uses Iron (III)-o-Phenanthroline reagent to
oxidize Nifuroxazide and the reagent is reduced to iron II ions with the subsequent
formation of an intense orange colored ferroin complex. The reaction proceeded in acetate
buffer medium and the color was measured at 510 nm.
The different experimental parameters affecting the development and stability of the
produced colors were carefully studied and optimized for the 2 methods. The two methods
were validated with respect to linearity, ranges, precision, accuracy, and limits of detection
and quantification. Beer’s law was obeyed in the concentration ranges of 4-12 and 1.6-8.0
Fg/mL for method I and method II respectively with correlation coefficient values not less
than 0.99948. In addition, detection limits were 0.52 and 0.18 Fg/mL for method I and
method II respectively. The proposed methods were successfully applied for the assay of
the drug in its capsules dosage form. Recovery data obtained by the proposed methods
were favorably compared with those obtained by a reported method.
Chapter III
This chapter deals with the development and validation of a spectrophotometric
method for the determination of Cisapride, Drotaverine and Loperamide by ternary
complex formation with eosin and Pb (II). The reaction between the drug, Pb (II) and eosin
is explained as ion association ternary complex of cationic binary complex with acidic dye.
The reaction mixture was found to absorb quantitatively at 545 nm.