Evaluation and comparison of release kinetics of an anti diabetic formulation

Abstract

Diabetes, a persistent endocrine disorder causing high rate of mortality, has been treated with adequate methods for the last hundred years after the discovery of insulin by Banting and Best though its clinical features were first described by the Egyptians 3000 years ago. The effective treatment strategies started to develop when the first oral hypoglycemic drugs, tolbutamide and carbutamide, came into the market. Presently, the establishment of new methods and strategies of combination therapy is considered to be more convenient over monotherapy. The main objective of this current study was to estimate a DPP-4 inhibitor named sitagliptin either alone or in a combination formulation with metformin. The quality of both available single and combination tablets of local companies with the innovator brand were also compared. The method followed for the determination of sitagliptin employed a RP‐HPLC procedure with PDA detector consisting of Luna 5μ C18column (250 mm x 4.60 mm) inserting an injection volume of 10μL and eluted by the mobile phase of 0.02 M potassium dihydrogen phosphate (pH4) and acetonitrile in a ratio of 60:40 respectively, which is pumped at a flow rate of 1.0 mL/min. The method carried out the detection at a wavelength of 252 nm for the binary mixture and of 210 nm for the single sitagliptin; and had the elution time of 3.45 and 2.28 minutes for sitagliptin and metformin respectively. All the values for system suitability parameters were also feasible with this method. The release kinetics profile of sitagliptin was very precise and accurate and can be concluded that this method is suitable for any tablet containing sitagliptin in the routine analysis of quality control laboratory.