Assessing the viability of Soluplus® self-assembled nanocolloids for sustained delivery of highly hydrophobic lapatinib (anticancer agent): Optimisation and in-vitro characterisation.

Nanocolloids are considered ideal carriers for hydrophobic drugs owing to their core-shell structure. Lapatinib is a potential anti-cancer agent, but its clinical use is limited because of its poor aqueous solubility, thus requiring larger oral doses with the associated toxicity. Thus, in the present study, we fabricated self-assembled nanocolloidal polymeric micelles (LP-PMs) of Soluplus® and Pluronic® F127 by the thin-film hydration method and assessed their delivery potential of the hydrophobic anti-cancer drug lapatinib (LP) and optimised these nanocolloidal polymeric micelles using Quality-by-Design approach. Amorphisation of the drug and no typical incompatibility other than hydrogen bonding in the LP-PMs was confirmed by solid-state characterisation. The LP-PMs exhibited a uniform size of 92.9 ± 4.07 nm, with a 5.06 mV zeta potential and approximately 87% drug encapsulation. The critical micellar concentration (CMC) of Soluplus® decreased from 6.63 × 10-3 to 4.4 × 10-3 mg/mL by incorporating Pluronic® F127. Further, the sustained release of LP from the LP-PMs was confirmed by in-vitro release studies showing 36% and 60% of LP released from the LP-PMs within 48 h in release media of pH 7.4 and pH 5.0, respectively. These results support their capability of preferential release at acidic tumor environment. Their hemocompatibility evidenced by hemolysis below accepted limits and no platelet aggregation with resistance to instant dilution illustrated their admirable blood compatibility and suitability for intravenous administration. The encapsulation of LP inside micelles enhanced the cytotoxicity of LP against SKBr3 breast cancer cells. Further, the LP-PMs were found to be stable over six months when stored at 2-8 °C. These findings indicate the improved potential of nanocolloidal polymeric micelles as promising carriers for the preferential and sustained delivery of hydrophobic anticancer drugs such as lapatinib to tumours.