Development and Optimization of Dihydrofolate-Targeted Methotrexate-Loaded Lyotropic Liquid Crystal-Based Gel for Localized Breast Cancer Therapy

Abstract

Breast cancer needs localized drug delivery strategies to improve therapeutic efficacy while minimizing systemic toxicity. This study aimed to develop and optimize methotrexate-loaded lyotropic liquid crystal nanoparticles (MTX-LLCs) and incorporate them into a topical gel for localized breast cancer therapy. MTX-LLCs were prepared by a top-down approach and optimized using a Box-Behnken design (BBD), with GMO (X1), Poloxamer 407 (X2), and probe sonication cycles (X3) as independent variables and entrapment efficiency (EE; Y1) and Vesicle size (Y2) as responses. The optimised formulation containing 2 mL GMO, 150 mg Poloxamer 407 and 20 cycles of sonication showed 92.14 ± 0.57% EE, 155.31 ± 2.41 nm vesicle size and 0.231 ± 0.07 PDI. The MTX-LLCs gel showed a prolonged release of drug (30.75 ± 4.25% at 48 h) compared to the conventional MTX gel (64.80 ± 3.38%). Ex vivo permeation and improved anti-cancer efficacy, suggesting it was improved to 246.5 ± 5.32 µg/cm² at 8 h, compared to 65.8 ± 5.47 µg/cm² for conventional gel. The optimized gel also showed better cytotoxicity against MCF-7 cells with an IC50 of 19.86 ± 2.18 µg/mL as compared to plain MTX of 42.16 ± 3.92 µg/mL. The formulation was shown to be stable regarding physicochemical properties, especially when kept at refrigeration temperatures. In conclusion, the Box-Behnken design was an effective tool for the optimization of MTX-LLCs, and its formulation into a topical gel offered sustained release, increased permeation and improved anti-cancer efficacy, which suggests its potential for localized breast cancer treatment.