Quantification and Engineering of Lipid Nanocapsule Formulations for the Delivery of Niclosamide as an Anti-Cancer...

Recent studies indicate that niclosamide demonstrates considerable promise as both an anthelmintic agent and a possible anticancer medication. Given the increasing interest in nano-sized drug delivery methods for cancer therapy, lipid nanocapsules (LNCs) have emerged as a viable approach to enhance the bioavailability of poorly soluble pharmaceuticals due to their beneficial properties. This research intends to develop niclosamide-loaded lipid nanocapsules (NIC-LNCs) using the phase inversion technique, followed by the optimization of these formulations via the Box-Behnken experimental design.

A reverse-phase high-performance liquid chromatography (RP-HPLC) method was devised and validated for quantifying niclosamide in the LNC formulations. Optimal chromatographic separation was attained utilizing an Agilent Eclipse XDB-C18 column (150×4.6 mm, 5 μm i.d.) with a mobile phase of a 50:50 (v/v) mixture of acetonitrile and 0.1% H₃PO₄ phosphate buffer, at a flow rate of 1.2 mL/min. The detection wavelength was set at 335 nm, and the analysis was performed at 35°C. The developed analytical methodology was validated through a comprehensive evaluation of accuracy, linearity, precision, limit of detection, limit of quantitation, specificity, and stability.

The optimization of the NIC-LNC formulation through the Box-Behnken design resulted in an optimal formulation labeled LNC5, consisting of 4% niclosamide, 20% lipid, and 20% surfactant. The proven RPHPLC method enables accurate quantification of NIC in the LNC formulations. The refined NIC-LNC formulation exhibited developed attributes as assessed by the design.

NIC-LNCs were successfully prepared with particle sizes below 100 nm, narrow size distributions (PDI<0.2), and negative zeta potential values in accordance with the literature. All formulations exhibited high encapsulation efficiency and sustained drug release profiles. The optimum formulation revealed a particle size of 43.29 ± 0.32 nm, encapsulation efficiency of 99.99 ± 0.02%, and drug release at one week of 68.85 ± 1.76%. The formulation maintained stability throughout the short-term study period.

The findings indicate that LNC systems are a promising method for drug administration, especially for anticancer drugs with limited solubility in water.