الفهرس 
Scope of WorkOnly 14 pages are availabe for public view
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Abstract
Two antiasthmatic drugs which are Ketotifen fumarfate and Theophylline were utilized to prepare a controlled delivery dosage forms which are achieved when carriers, such as; PEG 6000, Stearic acid and EudragitS were combined with the chosen drugs. The thesis aimed to control administration of a therapeutic dose at a desirable delivery rate. The thesis is devided into two main parts (Part I and II). Part I consists of two chapters, the first one (Chapter I) was directed to prepare a different formulation by using physical mixture, fusion and co precipitate techniques to prepare ketotifen in controlled dosage forms employing either stearic acid, eudragit S and polyethylene glycol 6000. The effect of method of preparation, the presence of surfactants and the pH of the release medium. on the preparations of physical mixture and solid dispersions were studied.. Existence of interaction between eudragit S and the drug was observed and has been confirmed by the disappearance of C=O group of the drug. Through the dissolution rate studies, the following order for dissolution rate was established: physical mixture >fusion method >co precipitate method. The effect of surfactant was found to be more significant in case of using stearic acid than that demonstrated in case of polyethylene glycol 6000. Chapter II, was concerned to bioavailability study; in which, selected formulations of ketotifen tablets were given to 24 adults human volunteers to follow up drug bioavailability. Blood samples were taken at time intervals and prepared, loaded into HPLC device. The results revealed that: Maximum concentration of ketotifen fumarate for all selected formulas were attained in 7.5 hours and The formula that achieved maximum concentration of drug in human body and also the higher bioavailability is that containing ketotifen fumarate with polyethylene glycol 6000. Part II: physical mixture, coprecipitate techniques were used to prepare theophylline in controlled dosage forms employing stearic acid or eudragit S. The effect of different preparative conditions on the preparations of physical mixture and solid dispersions were studied. The results concluded that: U.V spectra for Theophylline alone and in form of co precipitate of drug combined with stearic acid and eudragit S, shows no interference. Physical mixture for drugcarrier shows a higher release than that obtained with co precipitate. Increasing the polymer concentration would reduce the dissolution rate and the amount of drug released was decreased. Five percent of the surfactants used seem to be the optimum concentration at which the maximum release is obtained. In conclusion; Ketotifen and theophylline can be incorporated with carriers using fusion or coprecipitate techniques to formulate controlled release tablets with the desired effects.