This study deals with the production of an anti-diabetic tablet formulation containing the lyophilized aqueous leaf extracts (LS) of Lagerstroemia speciosa, Psidium guajava, Mangifera indica, Catharantus roseus and Syzygium cumini. Preformulation, acute to sub-acute toxicity studies, physico-chemical screenings and evaluation of the hypoglycemic effects of the LS was conducted. The finished tablet formulation was subjected to in-process quality control (IPQC) and accelerated stability study. LS was found to be non-toxic when given orally to rodents in acute and sub-acute settings. At daily oral doses of 1,000 and 1,500 mg/kg for 28 days, LS is equipotent with glibenclamide as a hypoglycemic agent. Preformulation of LS showed its secondary metabolite constituents, potentiometric titration curve, and proximate analytical profiles. Micromiretic analysis of the powdered blend was done prior to compression into tablets. IPQC tests showed dissolution of corosolic acid at 91.2 ± 2.65% after 1 hour. The shelf-life of corosolic acid in the finished product at 300C was found to be 223 months. This study demonstrated the feasibility of formulating an anti-diabetic tablet using the lyophilized combined aqueous leaf extract of 5 medicinal plants through preformulation profiling, IPQC tests and an accelerated stability study.