The aim of the study was to develop enteric coated tablets that will prevent omeprazole from degradation in acidic media by applying enteric coating solutions and facilitate release of omeprazole in small intestine which can be produced by local pharmaceutical industry. Formulation development is problematic area which has been experienced during assessment of applications for registration of medicines in Tanzania. It comprises of works published in two journals titled as Pre - formulation Studies for Generic Omeprazole Magnesium Enteric Coated Tablets and Formulation Development of Generic Omeprazole 20mg Enteric Coated Tablets. Chapter one which covers introduction, statement of problems, aim and the scope of the study. Chapter two covers literature review on various studies on treatment and management of peptic ulcers and concept of coating process in pharmaceutical industries including types of coating, coating equipments and challenges involving coating process. Chapter three covers the methodology involved in pre - formulation studies and formulation and optimization of manufacturing process. Chapter four is all about results and chapter five is discussion and conclusion.