FORMULATION OF VENLAFAXINE HCL AS GASTRO-RETENTIVE TABLET USING DIFFERENT CONCENTRATION OF HPMC AND ITS EVALUATION

The oral route is considered as the most promising route of drug delivery. Effective oral drug

delivery may depend upon the factors such as gastric emptying process, G I transit time of dosage

form, drug release from the dosage form and site of absorption of drugs. The gastro retentive drug

delivery systems retains in the stomach and assist in improving the oral sustained delivery of drugs

that have an absorption window in a particular region of the gastro intestinal tract. These systems

help in continuously releasing the drug before it reaches the absorption window, thus ensuring

optimal bioavailability. Floating tablets containing Venlafaxine Hydrochloride were prepared by wet

granulation technique using varying concentrations of polymers with sodiumbicarbonate. It was

found that gastro retention time of Venlafaxine Hydrochloride can be increased by formulating it in

a floating dosage form using optimum amount of HPMC, sodium bicarbonate and citric acid. The

floating tablets were evaluated for uniformity of weight, hardness, friability, drug content, invitro

buoyancy and dissolution studies. The produced floating tablets exhibited good floating time and

controlled drug release over a period of 8 hrs. It was concluded that floating tablet with good flow

property and controlled release property can be obtained by optimizing amount of HPMC, sodium

bicarbonate and citric acid. Among these formulations of Venlafaxine HCL, F12 showed maximum

release and sustained the action for the period and proved to be best.