Formulation and Evaluation of Floating Microspheres of Esomeprazole

Oral controlled release systems are designed to release the drug in-vivo with prediction so as to increase efficacy, minimize adverse effects and increase bioavailability of drugs. Floating drug delivery systems (FDDSs) are expected to remain buoyant in a lasting way upon the gastric contents. The various buoyant preparations include hollow microspheres, granules, powders, tablets, capsules, pills and laminated films. Floating microspheres are especially gaining attention due to their wide applicability in the targeting of drugs to the stomach. Floating microspheres (Hollow Microspheres) are gastro-retentive drug delivery systems based on non-effervescent approach. Hollow microspheres are in strict sense, spherical empty particles without core, free flowing powders consisting of proteins or synthetic polymers, ideally having a size in the range 1-1000 micrometer. Gastro-retentive floating microspheres are low-density systems that have sufficient buoyancy to float over gastric contents and remain in stomach for prolonged period. The drug is released slowly at desired rate resulting in increased gastric retention with reduced fluctuations in plasma drug concentration. Floating microspheres to improve patient compliance by decreasing dosing frequency, better the rapeutic effect of short half-life drugs can be achieved. Enhanced absorption of drugs which solubilize only in stomach, Gastric retention time is increased because of buoyancy. Floating microspheres are prepared by solvent diffusion and evaporation methods to create the hollow inner core.