A Review on Floating Microsphere

Abstract

The purpose of floating microsphere's is to improve gastric retention time. The Floating drug delivery systems are lower in the bulk thickness than the gastric juice and remain floating on gastric juice for long period of time without impacting gastric-emptying rate and increasing the bioavailability. The Gastro-retentive microspheres can particularly suitable for continuous and late release of the oral formulations with blending versatility to achieve the various release patterns, low dose risk as the reproducible and short gastric retention time. Ths gastric emptying is a complex process, one that is very highly variable and it makes in vivo performance of the drug delivery systems uncertain. The controlled drug delivery system with prolonged residence time in stomach can be of great practical importance for the drugs with absorption window in upper small intestine. The main limitations can attributed to inter- and intra-subject variability of the gastro intestinal (GI) transit time and to non-uniformity of the drug absorption throughout the alimentary canal. The floating or hydro dynamically controlled drug delivery systems are useful in such applications. Various gastro retentive dosage forms are available, including tablets, pills, laminated films, floating microspheres, capsules, granules and the powders. The floating microspheres (Hollow Microspheres) are the 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 micro meter. 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.