Controlled-Release Floating Drug-delivery Systems: A Comparative Review of Effervescent and Non-Effervescent Formulations
Chinna Reddy Palem *
Formulation R&D, Asphar Research Labs Pvt. Ltd., IDA, Balanagar, Hyderabad-500037, Telangana, India.
Sridhar Gumudevelli
Product Development, Ascent Pharmaceuticals Inc., 400S. Technology Drive, Central Islip, NY 11722, USA.
*Author to whom correspondence should be addressed.
Abstract
Background: Controlled-release floating drug delivery systems (FDDS) are advanced gastro-retentive dosage forms designed to prolong gastric residence time, enhance drug absorption in the upper gastrointestinal tract, improve oral bioavailability, and reduce dosing frequency. By maintaining buoyancy in gastric fluids, FDDS provide sustained drug release and are particularly advantageous for drugs exhibiting narrow absorption windows, site-specific absorption, pH-dependent solubility, or local therapeutic action within the stomach. These systems also have the potential to minimise gastrointestinal irritation and improve overall therapeutic efficacy.
Objectives: This chapter aims to provide a comprehensive scientific overview of controlled-release FDDS, with particular emphasis on the similarities and differences between effervescent and non-effervescent formulations. It critically examines the physiological basis of gastric retention, mechanisms of buoyancy, matrix hydration, swelling behaviour, and controlled drug release, while comparing the formulation principles, performance characteristics, and therapeutic applications of both floating systems.
Methodology: This chapter presents a critical review of the current scientific literature on floating drug delivery technologies. It discusses formulation design strategies, excipient selection, composition optimisation, and manufacturing approaches for floating matrix tablets and related gastro-retentive dosage forms. Furthermore, it reviews physicochemical characterisation methods, including mechanical strength, floating lag time, total floating duration, swelling behaviour, dissolution studies, drug release kinetics, and in vivo gastric retention assessments. Advanced analytical and imaging techniques for mechanistic evaluation are highlighted alongside commercially available products, patent developments, regulatory considerations, and recent technological advances such as multi-unit systems, novel polymers, hybrid gastro-retentive platforms, and computational formulation approaches.
Conclusion: Effervescent and non-effervescent floating drug delivery systems represent effective gastro-retentive strategies for achieving prolonged gastric residence and controlled drug release. Although both systems share the common objective of enhancing bioavailability and therapeutic performance, they differ substantially in buoyancy mechanisms, formulation design, polymer selection, manufacturing considerations, and release characteristics. Continued advances in material science, formulation technologies, computational modelling, and regulatory science are expected to facilitate the development of next-generation floating drug delivery systems with potential to improve therapeutic performance, reproducibility, scalability, and may enhance drug bioavailability. This chapter provides a comprehensive scientific framework to support future research, formulation development, and clinical translation of controlled-release floating drug delivery systems.
Keywords: Floating drug delivery systems, controlled release, effervescent formulations, non-effervescent formulations, floating lag time, in vivo gastric retention time