Formulation Development and Evaluation of Osmotic Drug Delivery System by Various Approaches: A Review

K. Sunil kumar¹, M.Kamali², A. Varaprasad^3
1Associate Professor, Department of Pharmaceutics, Sun Institute of Pharmaceutical Education and Research, Kakupalli, Nellore, Andhra Pradesh, India.
^2,3Sun Institute of Pharmaceutical Education and Research, Kakupalli, Nellore, Andhra Pradesh, India.

Abstract:
Various physical and chemical approaches have been applied to produce a well-characterized dosage form that controls drug input into the body within the specifications of the desired release profile. This is generally accomplished by attempting to obtain a “zero-order” release from the dosage form, i.e., the rate of drug release is independent of the drug concentration. Extended-release systems generally do not attain this type of release and usually try to mimic zero-order release. Also, factors like pH, presence of food, and other physiological factors may affect drug release from conventional CR systems (matrix and reservoir). Osmotic systems utilize the principles of osmotic pressure for the delivery of drugs. Drug release from these systems is independent of pH and other physiological parameters to a large extent and it is possible to modulate the release characteristics by optimizing the properties of the drug and system. At the same time, they can also be utilized to deliver drugs at a controlled and predetermined rate. Most cardiovascular events are prone to occur in the early mornings hours with the renewal of daily activities, and this is accompanied by various neurohumoral stimuli Precise knowledge of the circadian variations paves the way to designing an appropriate pharmacokinetic profile that ensures effective plasma concentration. The purpose of this work was to formulate a solid dosage form system (tablets) using the principles of osmosis which will bring down its dosing frequency to once a day and at the same time produce a zero-order release system. Osmotic drug delivery system viz. Monolayer osmotic Tablets (Elementary osmotic pump), Bilayer osmotic tablets (Push-pull osmotic pump) and trilayer osmotic tablets (Sandwiched osmotic tablet system) are going to prepare. The amount of polymers and osmogens to be incorporated in each formulation are going to decide by the optimization technique.
Keywords: Osmotic pressure, Pharmacokinetic, Sandwiched osmotic tablets, Elementary osmotic pump, Osmogens