الفهرس 
Introductory Part
Medicinal Importance of Polyhalogen CompoundsOnly 14 pages are availabe for public view
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Abstract
The thesis comprises four main parts :
Part I; constitutes a general introduction to pharma¬ceutical polyhalogens to gether with a review for the different methods used for the determination of organic polychloro compounds in general as well as the purpose of investigation.
Part II: In this part, an accurate and stability-indicating assay of chloral hydrate is described. The method depends upon the formation of a coloured Schiff
base ( ^ , 510 nm and £Mxf If 125) resulting from the
interaction of chloral hydrate sample with p-dimethylami.no. aniline solution. The effects of heating time, type and concentration of the acid catalyst, solvent, and pH on the rate and extent of colour formation wore investigated. Allied compounds and degradation products of chloral hydrate such as acetaldehyde, formaldehyde, acetone , chlorbutol, formic acid, chloroform, and trichloroacetic acid were found not to interfere • Accurate analysis of chloral hydrate in commercial syrups and in degraded samples waa possible without prior isolation, and with no interference, in the concentration range of 50-100 meg, per ml. with RSD of 0,005.
The spectroscopic as well as the chemical mechanistic rationale of the method are described.
Part III; This part deals with the photometric determin¬ation of chloramphenicol powder, capsules, syrups, vials, DROPs, and in the presence ox streptomycin, penicillin, and oxytetracycline. The method depends upon the reduction of chloramphenicol with sine powder and ealcium chloride solution followed ”by interacting the reduction inter¬mediate with 1-naphthylamine in acetic acid to form a pink-coloured dye ( ’AffiaS» 520 nm and <cmax* 9,072)* She different factors affecting the assay suoh as weight of zinc powder, caloium chloride concentration, heating times, and pH were investigated. Concentrations in the range of 10-30 meg. per ml can ”be analysed with a standard deviation of £0.6 $ .
This part includes also a study of the possible theoretical interpretation of the formation of the dye as well as the inter-correlation of the proposed method with analogous chromogen-forming reactions of chlorampheni-col.
Part IV : In this part, a novel modification of Fujjiwara reaction was developed. The part is subdivided into two sections. In the- first ons, analysis of some selected polychloro compounds of medicinal interest is outlined using nicotinic acid as* ohromogen developer. The effects
of different variables , e.g., sodium hydroxide concen¬tration, heating time, solvent, and pH were investigated. The analysis of chlorbutol in pharmaceutical formulations as well as degraded samples indicated the specificity of the method. Standard deviation was found to be + 0.36 f°* The procedure was applied quantitatively to chloral hydrate and chloroform.
In the second section, the reaction was extended in an inverse way to be applied far the analysis of pharma-ceutically important ^-substituted pyridine analogues e.g., nicotinic acid, nicotinamide, nikethamide «, Quan¬titative data obtained were of the same accuracy and precision obtainable with polychloro compounds .
The chemical foundation of the modification has been also explored with reference to related published reports.