الفهرس 
chapter 1Only 14 pages are availabe for public view
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Abstract
The present study aims to determine of some β-blockers drugs (Nebivolol hydrochloride, Bisoprolol fumarate, Desloratdine and Esomeprazole magnesium trihydrate in pure forms, formulations and biological samples by the proposed simple, rapid, accurate and sensitive spectrophotometric methods using oxidation reduction techniques.
The present thesis contains four chapters:
• Chapter I:
Includeointroductionoaboutoclassificationoofoβ-blockersodrugs, pharmacokinetic and pharmacodynamics properties of β-blockers drugs, mechanism of action of β-blockers drugs and their effect on kidney function, glucose and lipid metabolism. The specifications of the analytical methods used in β-blockers drugs determination, the requirements of the validation of these methods (sensitivity of spectrophotometric methods; precision, accuracy, detection and quantification limits and comparison of the results). Also an introduction about the β-blockersodrugs and reagents under consideration (the definitions, actions, chemical stuctures and chemical names).
• Chapter II:
Gives a literature survey of the previous studies for the analysis of the studied drugs and reagents including spectrophotometry, chromatography, electroanalytical and other methods.
• Chapter III:
Contains the experimental part which includes apparatus used for measurement, chemicals and procedures for the preparation of drugs and reagents solutions. It also contains in detailed explanation about the proposed spectrophotometric methods for determination of the studied drugs in pure forms, formulations and biological samples.
• Chapter IV:
Contains the result and discussion which include two parts, each part includes a procedure for determination of the drugs under investigation using oxidation reduction techniques:
1.kSpectrophotometrickdeterminationkofkstudiedkdrugskinkpure, pharmaceutical formulations and biological samples using cerium(IV) sulfate and two dyes
Simple, accurate, rapid and sensitive spectrophotometric methods have been proposed for the determination of some selected β-blockers drugs namely Nebivolol hydrochloride (NEB), Bisoprolol fumarate (BSF), Desloratdine (DSL) and Esomeprazole magnesium trihydrate (EMZ) in bulk and pharmaceutical formulations.
The first spectrophotometric method is based on a redox reaction between the selected drugs and Ce(IV) in acidic media. This indirect method in which oxidation of the drug solutions is occurred by a known excess of Ce(IV) in presence of H2SO4 followed by determination of the unreacted oxidant by its reaction with methyl red or amaranth dye, respectively. The absorbance was measured at 546, 526, 546 and 542 nm for NEB, BSF, DSL and EMZ, respectively against corresponding reagent blank similarly prepared by using methyl red (method A) but The absorbance was measured at 574, 528 and 574 nm for NEB, BSF and EMZ, respectively against corresponding reagent blank similarly prepared by using amaranth (method B). In all methods, the amount of cerium(IV) sulfate reacted corresponds to the amount of drug and the measured absorbance is found to increase linearly with the concentration of drug with correlation coefficients of 0.9991-0.9999. The beer’s law is obeyed in the concentration ranges 2-15 µg ml-1 (method A and B).
2.kSpectrophotometrickdeterminationkofkstudiedkdrugskinkpure, pharmaceutical formulations and biological samples using NBS and two dyes
The second spectrophotometric method is based on a redox reaction between the selected drugs and NBS in acidic media. This indirect method in which oxidation of the drug solutions is occurred by a known excess of NBS in presence of HCl followed by determination of the unreacted oxidant by its reaction with methyl red or amaranth dye, respectively. The absorbance was measured at 556, 556 and 556 nm for NEB, DSL and EMZ, respectively against corresponding reagent blank similarly prepared by using amaranth (method C) but the absorbance was measured at 560 and 572 nm for DSL and EMZ, respectively against corresponding reagent blank similarly prepared by using methyl red (method D), the absorbance increased linearly with increasing concentration of drug with correlation coefficients of 0.9990-0.9998. The beer’s law is obeyed in the concentration ranges 2-20 µg ml-1 (method C and D). when a fixed concentration of NBS was made to react with increasing concentration of the drugs, there occurred a concomitant fall in the oxidant concentration. when a fixed amount of each dye is added to decreasing amounts of NBS, a concomitant increase in its concentration.
The results showed that the proposed methods are advantageous over other official or reported methods with respect to their higher sensitivity with apparent high molar absorptivity for determination of the studied drugs. The proposed methods were successfully applied to determine the studied drugs in their formulations and biological samples. The results obtained were compared statistically with other reported methods by students’s t-test (for accuracy) and variance ratio F-test (for precision) at the 95 % confidence level. The results showed that the t- and F- values were less than the critical tabulated value indicating that there was no significant difference between the proposed and official or reported methods. Thus the proposed spectrophotometric methods can be applied in routine analysis for determination of the studied drugs in pure, pharmaceutical formulations and biological samples.