Methods of enabling or improving the ability of a hydrogel to swell in the 
stomach of an animal and / or increasing the amount of time said hydrogel remains swollen in the 
stomach are described herein. In one embodiment, a 
polymer is administered in combination with one or more pH modifying agents which raise and maintain the pH of the 
micro environment of the 
polymer and / or the 
stomach in order inducing swelling in the 
polymer. The polymer can be a homopolymer, a 
copolymer, or a 
polymer blend or composite. In one embodiment, the polymer is a 
superabsorbent polymer (“SAP”). The polymers can also be administered with one or more active agents, such as 
appetite suppressants. The pH modifying agent and / or the 
active agent can be administered simultaneously with the polymer in the same 
dosage form, simultaneously with the polymer in separate dosage forms, or sequentially. The compositions are formulated for 
oral administration. The formulation can include drugs for delivery to the stomach, such as 
antibiotics, or the hydrogel can be used as a filler, for example, for 
obesity control. The formulation an also be used to enhance gastric retention, for example, for controlled 
drug delivery. Methods of delivering a 
drug are also described herein, along with medicaments for carrying out the methods of the present invention.