DEVELOPMENT OF OPTIMIZED ANTICANCER DRUG NANOCRYSTALS FOR ENHANCED CELLULAR INTERNALIZATION, BIOPHARMACEUTICAL PERFORMANCE AND IN-VITRO ANTICANCER ACTIVITY

Abstract

Background: Cisplatin is an effective chemotherapeutic agent; however, its clinical application is limited by poor aqueous solubility, low cellular uptake, and suboptimal biopharmaceutical performance. Nanocrystal technology offers a promising strategy to overcome these limitations by enhancing dissolution and intracellular drug delivery. Objective: This study aimed to develop optimized cisplatin nanocrystals and evaluate their physicochemical characteristics, in vitro cytotoxicity, and anticancer efficacy against human colorectal (HT-29) and breast (MCF 7) cancer cell lines. Methods: Cisplatin nanocrystals were prepared by anti-solvent precipitation followed by high-pressure homogenization and optimized using a Quality by Design (QbD) approach. The optimized formulation was characterized for particle size, polydispersity index (PDI), zeta potential, crystallinity, thermal behavior, drug content, entrapment efficiency, and HPLC profile. Cytotoxicity was evaluated by MTT assay, and IC₅₀ values were determined using nonlinear regression analysis. Results: The optimized nanocrystals exhibited a mean particle size of 160 nm, PDI of 0.21, and zeta potential ranging from −45 to −50 mV, indicating a uniform and stable nanosystem. Drug content and entrapment efficiency were 98.2 ± 1.1% and 89.7 ± 1.4%, respectively. XRD and DSC analyses demonstrated partial amorphization without compromising thermal stability. The nanocrystals showed significantly greater cytotoxicity than pure cisplatin in both HT-29 and MCF-7 cells. At 40 µg/mL, cell viability decreased to 25.7 ± 1.9% in HT-29 cells and 28.6 ± 1.8% in MCF-7 cells, compared with 38.3 ± 2.2% and 40.2 ± 2.1%, respectively, for pure cisplatin. Moreover, the optimized formulation reduced the IC₅₀ values from 18.5 ± 1.2 to 12.5 ± 0.9 µg/mL in HT-29 cells and from 22.0 ± 1.4 to 15.0 ± 1.1 µg/mL in MCF-7 cells. Conclusion: The optimized cisplatin nanocrystals significantly enhanced physicochemical properties and in vitro anticancer activity compared with the pure drug, demonstrating their potential as an effective nanocarrier platform for improving the therapeutic performance of poorly soluble anticancer agents.