Integrated stability and metabolomic investigation of new Rifampicin and Isoniazid co-loaded liposome against tuberculosis

Objectives: This study aimed to develop and evaluate rifampicin (RIF) and isoniazid (INH) co-loaded liposome for sustained drug delivery to enhance therapeutic efficacy against tuberculosis (TB) and overcome challenges associated with prolonged treatment and drug resistance. Significance: The novel biocompatible liposomal system enables sustained co-delivery of RIF and INH, providing a scalable and stable platform with enhanced antimicrobial efficacy and strong potential to advance tuberculosis therapy. Methods: Liposome were prepared using soybean lecithin and cholesterol (L-CH) via rotary evaporator-assisted thin film hydration, optimized by Box-Behnken design, and characterized for size, PDI, entrapment efficiency, and physicochemical properties (FT-IR, DSC, HR-TEM). In vitro release, accelerated stability, antimicrobial efficacy against M. smegmatis and M. tuberculosis H37Rv, and LC-MS/MS-based metabolomic profiling were systematically evaluated. Results: The optimised liposome exhibited a mean size of 129.5 ± 2.20 nm, PDI of 0.369 ± 0.06, and entrapment efficiencies of 63.84 ± 1.62% (RIF) and 56.92 ± 1.69% (INH). The release study indicated sustained diffusion-controlled kinetics consistent with the Higuchi model, achieving cumulative releases of approximately 92% for INH and 85% for RIF over a 45-hour period. The accelerated stability studies confirmed negligible drug degradation, while antimicrobial assays demonstrated a twofold reduction in MIC relative to free drugs, and metabolomic profiling indicated modulation of glutathione, citric acid, and tyrosine pathways associated with enhanced redox balance and antimicrobial activity. Conclusions: The co-loaded RIF-INH liposomal system offers a promising, clinically translatable approach for sustained drug release and improved tuberculosis therapy.