This paper examined the release mechanism, dissolution-profile similarity and short-term accelerated stability of an optimised 500 mg metformin hydrochloride matrix tablet containing guar gum and HPMC K100M. dissolution data collected over 12 hours were fitted to zero-order, first-order, Higuchi, Hixson-Crowell and Korsmeyer-Peppas models. The optimised tablet released 25.1, 50.4, 76.3 and 95.2% at 1, 4, 8 and 12 hours. The Korsmeyer-Peppas model provided the strongest fit (R² = 0.995) with a release exponent of 0.68, while the Higuchi model also fitted closely (R² = 0.991). The results indicated a substantial diffusion component together with polymer relaxation or erosion. Comparison with a marketed reference gave f1 = 1.1 and f2 = 83.4, indicating in vitro profile similarity under the represented conditions. During six months at 40 °C/75% RH, assay declined from 100.0 to 99.1%, friability increased from 0.50 to 0.55%, and 12-hour release changed from 95.2 to 94.4%. The constructed findings illustrate how kinetic modelling, model-independent profile comparison and stability testing can provide complementary evidence after formulation optimisation. They do not establish bioequivalence, therapeutic equivalence or shelf life.