Background: Apigenin (APG), a natural bioactive flavonoid has multiple pharmacological effects. However, its poor aqueous solubility hinders its clinical benefits.
Objective and Methods: The work aimed to develop novel apigenin-loaded niosomes (APG-NIO) with ecological probe sonication techniques. The formulation was statistically optimized by Box-Behnken design (BBD) and the independent variables were selected as Span 80(X1), Poloxamer 188(X2), and Tween 80(X3) at three levels, and the dependent variables were identified as: particle size (Y1), polydispersity index (Y2), and % entrapment efficiency (Y3). The formulation was characterized for various parameters such as vesicle shape, size, PDI, %EE, solubility, in vitro drug release, and antioxidant potential.
Results: The optimized APG-NIO formulation was found to have a spherical shape with homogenous distribution and a low polydispersity index. It has a particle size of 425.77 nm, zeta potential -17.1±0.9 mV, and % EE of 89.63. The aqueous solubility of APG-NIO was found approximately 45 times higher than that of pure APG. The formulation showed a higher drug release rate as compared to pure APG in phosphate buffer pH 7.4 and followed the Higuchi release model with a non-Fickian transport mechanism. The stability was found at 4°C for 3 months. The antioxidant potential of APG-NIO was significantly increased in comparison to the pure drug suspension in the DPPH• assay.
Conclusion: These findings suggest that the probe sonication technique is an alternative, cost-effective, simple, and green method for the development of niosomes, and BBD is a useful optimization tool for identifying the effect of formulation variables.
Keywords: Apigenin, niosomes, probe sonication, box-behnken design, antioxidant, oral delivery.