Oral route of drug delivery system has become ever more important as pharmaceutical scientists acquire a better understanding of physio-chemical and biological aspects related to their performances. Matrix and sustained release formulations have further added new realms in conventional drug delivery. Emerging megaloporous inert matrix system can be viewed principally as a single-unit device that comprises two phases, which operate together to regulate the drug release from the dosage form with a constant rate to the dissolution liquids over an extended period of time. One of the structures is called the restraining-phase matrix granule (RMG) which comprises the drug and release rate-controlling material. The other structure is the housing-phase matrix granule (HMG) which contains drug and a penetration rate-controlling material. Furthermore, this phase develops a system of interconnected large pores.