الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
The sented thesis is concerned with the systematized study of the charge-transfer complexation reaction between seven cephalosporins as n-donors, with each iodine as a-acceptor; 2,3-dichoro-5,6-dicyano-1.4-benzoquinone (DDQ) and 7,7,8,8-tetracyaonquinodimethane (TCNQ) as K- acceptors. The studied drugs were cephalexin monohydrate, cefadroxil monohydrate, cephapirin sodium, cefazolin sodium, cefotaxime sodium, cefoperazone sodium and ceftazidime pentahydrate. The thesis falls into five parts :
The first part:
comprises a general literature review on the physical, medicinal and chemical properties of cephalosporins in addition to the different reported methods used for their analysis as well as the utility of CTC reactions in the pharmaceutical analysis.
The second part:
deals with the scope of the work.
The third part:
includes experimental in which the different factors affecting the proposed procedures, such as reaction time, concentration of the reagents and diluting solvents were studied.
The fourth part:
includes results and discussion as well as investigation on the structure of CTC. Accuracy, precision and sensitivity ranges of the different compounds analyzed were discussed. Calibration ranges were 6-50, 40-300 and 4-24 ng/mL for iodine, DDQ and TCNQ methods respectively. The proposed methods were also applied for the analysis of the different cephalosporins in some commercially available dosage forms with % recovery ranged from 96.47 ± 1.14-98.72 ± 1.02 in iodine method, 96.36 ±1.62-98.51 ±1.30 in DDQ method and 95.98 ± 0.78-98.40 ± 0.87. The results show good agreement with the results obtained from the official methods. The formation of CT-complex is supported by the uv/vis absorption bands at 290 and m for iodine, 460 nm for DDQ and 843 mn for TCNQ. Molar ratio is 1:1 between the studied cephalosporins and different reagents used Also the association constants and the standard free energy changes using Benesi-Hildebrand plots were studied. A considerable intermolecular overlap is indicated by the high values of the association constants obtained. In addition, the mechanism of interaction is supported with IR and lH-NMR spectroscopy. It could be concluded that the complex formation between cephalosporins and the used acceptors proceed mainly via the p-lactam nitrogen of the drug molecule. Side chain NH2, if present, will participate in the charge-transfer process.
The fifth part:
includes summary and conclusion.