By Shamsuddin Sultan Khan and Mesbah Uddin Talukder

Sustained-release dosage forms enable prolonged action of a drug in the body. Much research has focused on overcoming the short residence times and unpredictable gastric emptying times of drugs in sustained-release oral drug-delivery systems (1). A floating drug-delivery system floats in the gastric juice without affecting the gastric emptying rate. It forms a cohesive gel barrier that serves as a reservoir and releases the drug over the desired period of time. This technique helps increase a drug's gastric residence time and reduces the variability in bioavailability (2, 3). 

This article was also published in our US sister publication 

Pharmaceutical Technology Europe-12-01-2011

The authors developed a metronidazole-based floating drug-delivery system to investigate the effect of rate-controlling polymers on release pattern and duration of buoyancy in matrix tablets.