RESUMO
Oral dosage form has limited control over the release of drug from dosage form, hence effective plasma level concentration do not achieve at site of action. Such unusual pattern of dosing results in inappropriate or erratic blood plasma concentrations. The absorption of drug from conventional dosage form depends on factors such as-Physio-chemical properties of the drug, presence of excipient, physiological factors such as presence or absence of food, PH of the gastrointestinal tract etc. Present study highlights osmotically driven oral drug delivery system (tablet) containing celecoxib as an active ingredient. Patients with long term treatment of NSAID (e.g. Arthritis) and suffering from various gastrointestinal side effect will be benefited from such a dosage form. Majority of controlled release dosage forms available in market are generally matrix-based, their principal drug release mechanism was based on drug diffusion through the matrix. Such mechanism is changed by-the pH, presence of food, in the gastrointestinal tract. Body's physiological factors (G.I. motility) also contribute their role in unpredictable absorption. All these factors also affect the release of celecoxib from conventional oral dosage form. Osmotic systems utilize the principle of osmosis as delivery force to release the drug from the dosage form, and the release rate has no effect of the body's pH and other physiological factors, also the various side effects due to long term therapy of NSAIDs are reduced. Batch 6 coated with semipermeable membrane give the maximum of 90.28% release from elementary osmotic tablet in control manner up to 8 hours and following zero order release, other batches e.g. 4and 8 coated with microporous membrane follow first order release.