Gastro-Retentive Floating Drug Delivery Systems of Metformin Hydrochloride: A Comprehensive Review

Abstract

Metformin Hydrochloride is one of the most prescribed oral antidiabetic agents in the management of Type II Diabetes Mellitus. However, its short biological half-life, incomplete gastrointestinal absorption and frequent dosing have prompted the development of advanced drug delivery systems to improve its therapeutic effectiveness. Gastro-retentive floating drug delivery systems (FDDS) have gained attention as a promising approach to prolong gastric residence time, improve drug absorption and offer sustained drug release. The present review offers a comprehensive discussion on formulation approaches, evaluation parameters, drug release mechanisms, therapeutic significance and challenges of floating tablets of Metformin Hydrochloride. Different formulation strategies using hydrophilic polymers such as Hydroxypropyl Methylcellulose (HPMC), Carbopol, Sodium Alginate, Xanthan Gum, and other matrix-forming agents have been studied to achieve prolonged buoyancy and controlled drug release. This review also highlights the importance of pre-compression and post-compression evaluation parameters, such as flow properties, hardness, friability, floating lag time, total floating duration, and drug content uniformity, in ensuring the quality and performance of the formulation. In vitro dissolution studies have revealed that the type and concentration of polymers have a significant effect on the release behavior of the drug. Carbopol-based formulations often exhibit better sustained release characteristics and prolonged gastric retention. Despite great progress, there are several challenges, including variability in gastric physiology, high drug loading requirements, formulation stability, scale-up difficulties, and regulatory issues. However, available evidence indicates that floating tablets of metformin hydrochloride offer an effective gastro-retentive platform that can improve bioavailability, reduce dosing frequency, and improve patient compliance. In conclusion, floating drug delivery systems may be a potential strategy to improve oral metformin therapy and achieve better outcomes in long-term diabetes management.