Integrating a multistage DoE strategy using Plackett-Burman screening and Box-Behnken optimization to develop cefuroxime transfersomal patch for diabetic ulcer biofilm eradication.

BACKGROUND: Biofilm (BF)-forming S. aureus and P. aeruginosa are present in Diabetic ulcers (DUs) showing high tolerance to conventional antibiotics. Cefuroxime (Cef) exhibits strong activity but low skin permeability and low BF penetration. OBJECTIVE: To design and develop a Cef loaded-transfersomal patch for better topical delivery and BF eradication in DUs. METHODOLOGY: 11 variables were screened by Plackett-Burman design (12 runs) and five variables found to be critical were optimized by Box-Behnken design (46 runs). Transfersomes were optimized and embedded in HPMC K5 patches. Characterization included size, PDI, zeta potential, entrapment efficiency, deformability index, FTIR, DSC, ex-vivo permeation, and stability. Anti-BF activity was determined by MBEC, time-kill activity and crystal violet assay. RESULTS: The optimized formulation yielded transfersomes with mean size 178.3±4.8 nm (PDI 0.28±0.01), zeta potential -34.3±0.7 mV, entrapment efficiency 79.3±0.6%, deformability index 4.5±0.1, and 24 hrs drug release 77.7±1.6%. Patches showed an even thickness, folding endurance >175, drug content 86.6%, and cumulative skin permeation 136 μg/cm2 (≈12.6% of load). Amorphous drug dispersion was confirmed by DSC. Importantly, the patch was effective in reaching MBEC values of 21 μg/ml and 45 μg/ml respectively against S. aureus and P. aeruginosa in 8-12 hrs, which represents ≥3 log10 reduction. BF mass reduction was observed by crystal violet assay. The accelerated stability showed no significant difference in the critical quality attributes. CONCLUSION: This patch platform with transferosomal technology significantly improves the skin permeation of Cef and the eradication of BF, offering new therapeutic possibilities for the treatment of DUs linked with BF.