The purpose of controlled release systems (CRS) is to maintain drug concentration in the blood or in target tissues at a desired value as long as possible. In other words, they are able to exert a control on the drug release rate and duration. Matrix technologies have often proven popular among the oral controlled drug delivery technologies because of their simplicity, ease in manufacturing, high level of reproducibility, stability of the raw materials and dosage form, and ease of scale-up and process validation. Developing oral controlled release tablets for water soluble drugs with constant release rate has always been a challenge to the pharmaceutical technologist. Most of these water soluble drugs if not formulated properly, may readily release the drug at a faster rate and produce a toxic concentration of drug on oral administration. Hence it is a challenging task to formulate a suitable tablet dosage form for prolonged delivery of highly water soluble drugs.