Omega-3 fatty acid-based self-microemulsifying drug delivery system (SMEDDS) of pioglitazone: Optimization, in vitro and in vivo studies

Pioglitazone (PGL) is an effective insulin sensitizer, however, side effects such as accumulation of subcutaneous fat, edema, and weight gain as well as poor oral bioavailability limit its therapeutic potential for oral delivery. Recent studies have shown that combination of both, PGL and fish oil significantly reduce fasting plasma glucose, improve insulin resistance, and mitigate pioglitazone-induced subcutaneous fat accumulation and weight gain. Nevertheless, developing an effective oral drug delivery system for administration of both medications have not been explored yet. Thus, this study aimed to develop a self-micro emulsifying drug delivery system (SMEDDS) for the simultaneous oral administration of PGL and fish oil. SMEDDS was developed using concentrated fish oil,Tween® 80, and Transcutol HP and optimized by central composite design (CCD). The reconstituted, optimized PGL-SMEDDS exhibited a globule size of 142 nm, a PDI of 0.232, and a zeta potential of −20.9 mV. The in-vitro drug release study of the PGL-SMEDDS showed a first-order model kinetic release and demonstrated remarkable 15-fold enhancement compared to PGL suspension. Additionally, following oral administration in fasting albino Wistar rats, PGL-SMEDDS exhibited 3.4-fold and 1.4-fold enhancements in the AUC(0–24h) compared to PGL suspension and PGL marketed product. The accelerated stability testing showed that the optimized SMEDDS formulation was stable over a three-month storage period. Taken together, our findings demonstrate that the developed fish oil-based SMEDDS for PGL could serve as effective nanoplatforms for the oral delivery of PGL, warranting future studies to explore its synergistic therapeutic potential in rats.