Design and Development of Controlled Sustained Release Formulations for Certain Newer Drugs

Abstract

The present thesis deals with the investigations carried out by the writer on the development and evaluation of oral sustained release formulations, namely, tablets and spheroids using a novel polysaccharide isolated from Delonix regia and to improve the pharmacotherapy associated with the selected drug candidates. The first chapter of the thesis deals a brief account of the trends in drug delivery systems and an introduction to oral drug delivery systems along with the detailed account of polymeric drug delivery based both on the design of the device and mechanism of drug release. A brief note on the hydrophilic matrices, polysaccharides used for hydrophilic matrices, single and multiple unit dosage forms, pellets and spheroids along with a literature review on the isolation of polysaccharides from plant sources and work done by earlier investigators on the development of sustained release formulations if any in the drug selected is also discussed. The scope and objectives of the present investigation along with the plan of work is presented in the second chapter of the thesis. The importance of polysaccharides in drug delivery systems and the need for the development of novel polysaccharide hydrogels is emphasized. The rationale for the development of sustained release drug delivery systems and advantages of these delivery systems for the selected drug candidates is also discussed. The third chapter gives a detailed account of the materials and the experimental techniques used for the isolation, characterization and toxicity studies on the novel polysaccharides isolated, preformulation studies, development and evaluation of oral sustained release tablets and spheroids, stability studies, bioanalytical method developed used for the estimation of the selected drugs in plasma and its validation. Bioavailability studies carried out on both rabbits and humans are described. The fourth chapter describes in detail the experimental results obtained in the present investigation along with a detailed discussion. newline