QbD-driven formulation development and evaluation of apigenin loaded chitosan-tethered in-situ cubosomal gel for the management of cervical cancer: A preclinical study.

Abstract

Cervical cancer remains a significant global health burden, particularly in low- and middle-income countries, necessitating the development of effective localized therapeutic strategies. The present study focuses on the Quality by Design (QbD)-driven development and optimization of an apigenin-loaded chitosan-tethered in situ cubosomal gel for enhanced management of cervical cancer. Apigenin, a potent flavonoid with anticancer and anti-angiogenic properties, suffers from poor aqueous solubility and limited bioavailability, which restricts its clinical application. To overcome these limitations, cubosomal nanocarriers were formulated using glyceryl monooleate and Pluronic® F127, and optimized via central composite design (CCD) by evaluating critical quality attributes, including particle size, polydispersity index (PDI), and % entrapment efficiency. The optimized cubosomes exhibited a particle size of 253.9 nm, a low PDI of 0.06, a zeta potential of -24.4 mV, and an entrapment efficiency of 84.1 ± 1.25%, indicating a stable and efficient delivery system. Transmission electron microscopy confirmed the presence of discrete, cubic nanostructures with uniform morphology. The incorporation of cubosomes into a thermosensitive in-situ gel and surface modification with chitosan significantly improved formulation stability and enabled controlled drug release. The MTT assay revealed superior cytotoxicity of the optimized gel (IC50 = 2.753 ± 0.05 μg/mL) compared to free AGN (IC50 = 6.618 ± 0.15 μg/mL). Confocal microscopy confirmed improved cellular uptake, and the CAM assay demonstrated significant antiangiogenic activity via VEGF/HIF-1α suppression. These findings highlight the potential of CHT-AGN-CB-gel as a promising localized delivery platform for cervical cancer management, offering sustained release and reduced systemic toxicity.