Dipyridamole is a poorly soluble, weakly basic drug with a narrow absorption window in the upper gastrointestinal tract, making it a suitable candidate for gastroretentive drug delivery systems. The present study was aimed at the design, formulation, evaluation, and statistical optimization of controlled-release floating tablets of dipyridamole using the dry-coated (compression-coated) technique. The dry-coated approach was employed to achieve immediate buoyancy combined with prolonged drug release. Core tablets containing dipyridamole were prepared by direct compression, while outer coating layers consisted of hydrophilic polymers such as hydroxypropyl methylcellulose (HPMC K4M and HPMC K15M) along with gas-generating agents. The formulated tablets were evaluated for physicochemical properties, floating behavior, in vitro drug release, and release kinetics. Statistical analysis was performed to assess the influence of formulation variables on floating lag time and cumulative drug release. The optimized formulation exhibited negligible floating lag time, sustained buoyancy exceeding 12 hours, and controlled drug release following non-Fickian diffusion. The study demonstrates that dry-coated floating tablets are a promising strategy for enhancing gastric residence time and improving the controlled delivery of dipyridamole.

Dipyridamole; Floating tablets; Dry-coated method; Gastroretentive drug delivery; Controlled release; Statistical analysis