The present disclosure provides floating gastroretentive compositions comprising a multilayer core comprising 1) a pull layer containing liothyronine or a pharmaceutically acceptable salt thereof, an acid, and a gas-generating agent; and 2) a push layer. Each of the pull layer and the push layer comprises a swellable water-soluble hydrophilic polymer. The composition further comprises a permeable elastic membrane covering at least a portion of the multilayer core and containing at least one orifice in fluid communication with the pull layer. The permeable elastic membrane comprises a copolymer of ethyl acrylate, methyl methacrylate, and trimethylammonioethyl methacrylate chloride. The composition provides sustained release of liothyronine or a pharmaceutically acceptable salt thereof.