Formulation Development and Characterization of Tolterodine Tartrate Extended Release Multiple Unit Pellet System

Abstract

Tolterodine Tartrate is Muscarinic receptor antagonist which is used in the treatment of Urinary frequency in patients with over active Bladder disease. The aim of the present work was to develop an extended release dosage form of Tolterodine tartrate using Multi particulate drug delivery system that will reduce the dosing frequency and will make the drug available for the longer period of time. The purpose of selecting multi-particulate system is to develop a formulation having all the advantages of Conventional/monolithic system and yet do not have disadvantage of alteration in drug release due to unit to unit variation. Tolterodine Tartrate is a BCS Class-I drug and also a potent drug having a dose of 4 mg once a day. In the present investigation, Solution Layering Technique was adopted due to low dose of drug that allows us to spray the desired amount of drug on the starter cores. To design this dosage form, first of all inert cores of suitable size were selected and drug was coated onto the pellets along with binder. In the drug layering the ratio of drug to HPMC as well as Methanol: Water was optimized and the effect was analysed. The drug layering was followed by coating with water insoluble polymer that retard the drug release. The controlled release coated pellets were further coated with drug layering solution followed by extended release coating of ethyl cellulose in the form of aqueous dispersion along with pore forming agent. The ratio of water insoluble polymer and pore former was optimized to get the desired drug release profile. The curing time required at each stage of coating was optimized to achieve the complete film formation. These pellet were filled in the capsules of suitable size. The coated pellets were evaluated for assay, percentage yield, and in-vitro drug release study. The formula was optimized to generate the formulation which gives same release profile as that of marketed formulation. Hence the present study concludes that multi particulate drug delivery system gives efficient drug release over an extended period of time...