Gabapentin is a hydrophilic anticonvulsant and neuropathic-pain agent whose oral bioavailability is limited by a narrow, saturable absorption window confined to the stomach and proximal small intestine, making it a rational candidate for gastroretentive drug delivery. The present study aimed to formulate and evaluate non-effervescent gastroretentive floating tablets of gabapentin using the sublimation technique, with camphor as the pore-forming (sublimating) agent, thereby avoiding the erratic buoyancy associated with gas-generating effervescent systems. Nine formulations (F1–F9) were prepared by wet granulation using HPMC K100 and guar gum as matrix-forming polymers and camphor at graded concentrations, followed by post-compression sublimation of camphor in a hot-air oven. Pre-compression powder blends and post-compression tablets were evaluated for flow properties, physical parameters, floating behaviour, swelling index, drug content, and in-vitro drug release over 12 hours. All formulations showed a floating lag time of 0 seconds. Formulation F5 (HPMC K100 130 mg, guar gum 30 mg, camphor 50 mg) was selected as optimized, exhibiting a floating duration exceeding 24 hours, drug content of 99.5%, a swelling index of 190% at 8 hours, and a cumulative drug release of 96.8% at 12 hours. Release-kinetic modelling showed the best fit to the Korsmeyer–Peppas model (R² = 0.995) with a release exponent (n) of 0.67, indicating non-Fickian (anomalous) transport governed jointly by diffusion and polymer relaxation. One-way ANOVA confirmed statistically significant differences among formulations for drug release, floating behaviour, and swelling (p < 0.0001). These findings demonstrate that the sublimation technique using camphor is a simple, reproducible, effervescent-free approach for achieving immediate and prolonged gastric buoyancy, and that the optimized formulation represents a technically feasible strategy for prolonging the gastric residence and improving the site-specific absorption of gabapentin.