Development and Validation of a Stability Indicating Analytical Method for the Estimation of Gliclazide and Sitagliptin in Bulk Drugs and Tablet Dosage Forms by RP-UPLC: An Application of the Quality-by-Design Approach

Sitagliptin and gliclazide are the active ingredients in OpdualagTM. A highly selective DPP-4 inhibitor, sitagliptin is thought to work in type 2 diabetics by delaying the inactivation of incretin hormones, which increases their concentration and lengthens their duration of effect. Sulfonyl urea mostly enhances insulin secretion from pancreatic β-cells by inhibiting ATP-sensitive K+ channels, leading to depolarisation and Ca2+ influx. Reduced serum glucagon levels and enhanced insulin binding to receptors and target tissues are the mechanisms by which it exerts its effects. Objective: This study aims to create and evaluate an RP-UPLC technique for the detection of sitagliptin and gliclazide in pharmaceutical products by applying AQbD principles. Method: Findings By utilising the Design-expert® programme, we were able to execute a central composite design (CCD) consisting of three components arranged in five distinct layers, which greatly improved the chromatographic conditions. One method that oversees the whole analytical procedure life cycle—from method design and optimisation to validation and continual improvement—is Analytical Quality by Design (AQbD). Results: The retention times for sitagliptin were 1.269 minutes and for gliclazide they were 1.572 minutes. The limits of detection (LOD) and quantitation (LOQ) for Sitagliptin and Gliclazide were 0.19 µg/mL, 0.56 µg/mL, 0.28 µg/mL, and 0.86 µg/mL respectively. The recovery percentages for sitagliptin and gliclazide were found to be 99.15% to 100.54% and 99.93% to 100.58%, respectively. Both drugs were found to be susceptible to oxidative and photolytic breakdown in the forced degradation studies. Conclusions A novel RP-UPLC method has been developed for the quantitative detection of sitagliptin and gliclazide in pharmaceutical formulations, utilising the AQbD-based methodology. This approach is straightforward, rapid, precise, particular, and stable-indicating.