LITERATURE REVIEW OF ORAL TREATMENT OF TYPE 2 DIABETES MELLITUS

Type 2 non-insulin-dependent diabetes mellitus (T2DM), the most common form of diabetes that affects more than 90% of diabetic patients, is characterized by insulin resistance, beta-pancreatic cells dysfunction, and increased hepatic glucose synthesis. The aim of the present paper was to review data on the efficacy of conventional oral dosage forms compared to controlled oral drug delivery systems for treating diabetes. Although the number of oral antidiabetic drugs has significantly increased in recent years, clinically there are still important limitations in terms of therapeutic efficacy, tolerability, and adverse effects, particularly regarding weight gain and medium and long-term glucose control. The last generation of oral pharmaceutical formulations such as modified-release tablets overcame some limitations, while injectable formulations with glucagon-like peptide-1 receptor agonists significantly increased the effectiveness of anti-diabetic medication and significantly reduced diabetes-specific comorbidities. Metformin extended-release formulation seems to be more effective than metformin conventional-release formulation in improving glyco-metabolic control, lipid profile, and levels of some adipocytokines in T2DM. Sustained-release glipizide formulation increases the compliance compared to immediate-release glipizide because it seems to achieve similar glucose control with decreased insulin secretion and to decrease the frequency of hypoglycemic episodes. Gliclazide modified release formulation seems to be effective and safe in T2DM with suboptimal glycemic control. Modified release formulations generate other advantages such as increasing treatment compliance, lowering the dose of drug substance, and even reducing side effects.