Quality by Design (QbD), a concept introduced by Dr. Joseph M. Juran, emphasizes the design of quality into product. Quality-by-Design is defined as “a systematic approach to pharmaceutical development with predefined objectives”. This approach emphasizes product and process control, based on sound science and quality risk management. A high quality drug product, as defined by Janet Woodcock (Director for the Center for Drug Evaluation and Research), is a product free of contamination which can consistently deliver the clinical performance and therapeutic effects as indicated in the label. It was recognized that the quality of product doesn’t improve with increased testing. Following equation indicates the factors affecting quality.