Development and validation of RP-HPLC method for quantification of repaglinide in mPEG-PCL polymeric nanoparticles: QbD-driven optimization, force degradation study, and assessment of in vitro release mathematic modeling

Abstract

Repaglinide (REP) an insulinotropic agent used in the treatment of type-2 diabetes. It belongs to meglitinides, which act by blocking the ATP sensitive potassium channels and stimulates the insulin release. REP is the first insulin secretagogue used to target postprandial hyperglycemia. In this study, a rapid, sensitive, and reproducible RP-HPLC method has been developed and validated using an analytical quality-by-design approach. Initially, the Ishikawa fishbone diagram provides the basis of variation in critical analytical attributes with various inputs. Additionally, Taguchi design was selected to screen the critical method parameters affecting method development. Further, systemic optimization of the RP-HPLC method was determined by using Box-Behnken design. The chromatography separation was achieved by acetonitrile and phosphate buffer (60:40) with isocratic flow system on waters Nova-pack C18 column (3.9 × 150 mm, 4 μm) with 0.8 mL/min flow rate and the developed method was validated as per ICH guidelines. Moreover, the force degradation studies were also performed under different conditions (acidic, basic, oxidation and photolytic) to understand the degradation pathways and products. Furthermore, an amphiphilic di-block biodegradable polymer, i.e., polyethylene glycol-polycaprolactone (mPEG-PCL) was synthesized with different molecular weights to encapsulate REP and understand the release kinetics with mathematical modeling. In addition, the validated RP-HPLC method was effectively utilized to determine percent entrapment efficiency and loading efficiency of REP loaded nanoparticles. The developed method would also be applicable to quantify the REP from the biological matrix.