Abstract

Metoprolol succinate is a beta 1- selective (cardio selective) adrenergic antagonist. Metoprolol succinate competes with adrenergic neurotransmitters such as catecholamines for binding at beta (1) adrenergic receptors in heart. Metoprolol succinate is the drug of choice for hypertension. Metoprolol succinate is considered to be absorbed in upper part of GIT (duodenal) it has 3-7 hrs. half-life and 50% bioavailability. Therefore, an attempt is made to release the drug for longer period of time. This is achieved by developing Osmotic Drug Delivery System i.e. Controlled Porosity Osmotic Pump Drug Delivery System. These controlled porosity osmotic pump tablets of Metoprolol succinate mainly prepared for increasing to release the drug upto 12 hrs. thereby increasing the bioavailability of the drug leading to reduced frequency of dosing. The osmoisis based controlled porosity osmotic pump drug delivery systems were formulated using sodium chloride along with pore former like polyethylene glycol 400 and lactose was selected for formulation. Formulations F1-F4 were prepared using microcrystalline cellulose (diluent) along with other excipients such as PVP K-30 (Binder), Magnesium stearate (Lubricant). Formulations F1-F4 were coated by using coating polymers such as polyvinyl alcohol and cellulose acetate along with other excipients such as polyethylene glycol 400 (pore former), castor oil (Plasticizer) with different solvent system such as Acetone : Ethanol (80:20) and Water: Ethanol (80:20). Effect of variables like the osmogene concentration, effect of pH and effect of pore former concentration in alone that influenced drug release from various formulations were studied.