Quality by Design Approach for Developing Lipid-Based Nanoformulations of Gliclazide to Improve Oral Bioavailability and Anti-Diabetic Activity

The aim of the current investigation was to generate a self-nanoemulsifying drug delivery system (SNEDDS) of gliclazide (GCZ) to address the poor solubility and bioavailability. Ternary phase diagram was created with Capmul MCM C8 NF (oil), Cremophor RH 40 (surfactant), and Transcutol HP (co-surfactant) to distinguish the self-emulsifying region. A D-optimal design was employed with three variables, such as oil, surfactant, and co-surfactant, for further optimization of liquid (L)-SNEDDS. GCZ-loaded L-SNEDDs were analyzed for globule size, polydispersity index (PDI), and solubility. In vitro dissolution of optimized L-SNEDDS exhibited (F5) faster drug release (97.84%) within 30min as compared to plain drug (15.99%). The optimized L-SNEDDS was converted to solid (S)-SNEDDS as a self-nanoemulsifying powder (SNEP) and pellets by extrusion-spheronization. Optimized S-SNEDDS were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). In vitro dissolution of SNEP (S3) and pellet were 90.54 and 73.76%, respectively, at 30min. In vivo studies showed a twofold rise in bioavailability through SNEDDS with a significant decline in blood glucose levels compared to plain drug suspension suggesting a lipid-based system as an alternative approach for treating diabetes.