Abstract: 
The purpose of writing this review on floating drug delivery systems (FDDS) was to focus on the principal mechanism of floatation to achieve gastric retention. The recent developments of FDDS including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, and their classification and formulation aspects are covered in detail. The purpose of this paper is to review the recent literature and current technology such as several approaches are currently utilized in the prolongation of the GRT, including floating drug delivery systems (FDDS), also known as hydrodynamically balanced systems (HBS), swelling and expanding systems, polymeric bioadhesive systems, high-density systems, and other delayed gastric emptying devices used in the development of gastro retentive dosage forms.

Keywords: Floating Drug Delivery System (FDDS), Gastrointestinal Track (GIT), Gastric Retention Time (GRT), Effervescent Systems, Noneffervescent Systems.