ABSTRACT:
The immediate release conventional dosage form lack in the efficiency of controlling the proper plasma drug concentration. This results in the development of various controlled drug delivery system. Osmotic drug delivery systems are new approach for a controlled release dosage form. Various patents available for osmotic drug delivery system like Rose-Nelson pump, Higuchi-Leeper pump, Higuchi Theeuwes pump, Elementary Osmotic Pump etc. Among which the Pulsatile drug delivery systems (PDDS)/ osmotic controlled drug delivery system (OCDDS) are gaining importance as these systems deliver the drug at specific time as per the path physiological need of the disease, resulting in improved patient therapeutic efficacy and compliance. They work on the principle of osmotic pressure for controlling the delivery of the drug. The main clinical benefits of OCDDS are their ability to improve treatment tolerability and patient compliance. These advantages are mainly driven by the capacity to deliver drugs in a sustained manner, independent of the drug chemical properties, of the patient’s physiological factors or concomitant food intake. OCDDS are useful for poorly soluble drug, for pulsatile drug release and zero order release. Various techniques available for preparation of OCDDS include push pull osmotic Pump, osmotic Bursting osmotic pump, liquid oral osmotic system, sandwiched osmotic tablets (SOTS), delayed delivery osmotic device, and controlled porosity osmotic Pump. This review highlights’ the theoretical concept of drug delivery, history, types of oral osmotic drug delivery systems, advantages and disadvantages of this delivery systems , theoretical aspects, applications, marketed status and last but not the least the recent development.