A Novel Expandable Core of Elementary Osmotic Pump: an Effective Device for Delivery of Poorly Water-soluble Drugs

The main intention of the present work is to design and evaluate a new Elementary Osmotic Pump (EOP) for efficient delivery of Poorly Water-Soluble Drugs (PWSDs). Drug release from the new system called Expandable EOP (EEOP), is through a porous semipermeable membrane in the form of a suspension ready for dissolution and absorption. EEOP tablets were prepared by compressing the mixture of drug and excipients into convex tablets. PWS antidyslipidemic drug Nicotinic acid (NA) is used as model drug. Guar gum (GG) is used as an osmotic, suspending and expanding agent and cellulose acetate as Semipermeable Membrane (SPM) containing Polyethylene glycol (PEG) as plasticizer. The effect on the in vitro dissolution profile of NA was examined using varying GG percentage content in the formulations. The influences of GG, PEG and SPM thickness on the NA release profiles of optimal tablet were the focus of study. The optimal tablet was found to deliver NA at the rate of approximately zero order upto 12 hours, independent of environment media and stirring rate. The accelerated stability studies of optimal tablet made it clear that negligible amount of drug content degraded and release pattern was almost unaffected and could be claimed to be stable upto six months. The ƒ1 and ƒ2 analysis of NA before and after storage is almost superimposable. Hence it is concluded that, these EEOP can be recommended for use in oral drug controlled delivery field, especially for PWSDs.