Expanding arsenal against diabetes mellitus through nanoformulations loaded with glimepiride and simvastatin: a comparative study

Type 2 diabetes mellitus is one of the most common and life-threatening diseases found across the globe. It occurs due to insulin resistance (IR). Major causes of IR include obesity, sedentary life style and hyperlipidemia. Glimepiride (GLM) is one of the most common oral sulphonyl ureas that is being used to treat diabetes and Simvastatin (SIM) is one of the most common statins that is used to treat hyperlipidaemia. However, both the drugs suffer from dissolution rate limited oral bioavailability. Hence, the aim of present study was to develop two different nanoformulations viz. nanosuspension and self-nanoemulsifying drug delivery systems (SNEDDS) and evaluate their potential in treating type 2 diabetes mellitus on streptozotocin (STZ) induced rats. In the present study two such drugs, GLM and SIM were co-formulated into nanosuspension (NS) as well as self-nanoemulsifying drug delivery systems (L-SNEDDS). Both formulations were spray dried for solidification and evaluated for their antidiabetic potential against high fat diet and streptozotocin induced rat model. The study showed significant (p < 0.05) decrease in lipid/cholesterol and blood glucose levels and significant increase in antioxidant levels in the rats treated with NS and SNEDDS containing the drugs alone as well as their combination as compared to their unprocessed forms. However, the efficacy was more prominent in case of combination possibly due to dual benefits i.e., decrease in IR due to statin and control of blood glucose level. Among NS and SNEDDS, NS was found more efficacious than that of the SNEDDS possibly due to higher enhancement of oral bioavailability in case of NS.