In-Vitro Evaluation of Doxycycline–Cefixime Nanoparticles against MDR S. Typhi
Abstract
Multidrug-resistant and extensively drug-resistant Salmonella enterica serovar Typhi remain major threats in South Asia, particularly where empirical treatment is weakened by fluoroquinolone non-susceptibility, ceftriaxone resistance and emerging azithromycin resistance. The present model manuscript develops an in-vitro research design for doxycycline- and cefixime-loaded chitosan-alginate nanoparticles as a concerted antibacterial platform. Doxycycline was selected to exert ribosomal protein-synthesis pressure, while cefixime was selected to target cell-wall synthesis; chitosan-alginate nanoparticles were selected to improve mucoadhesion, controlled release, local concentration and bacterial-surface interaction. The study is written as an academic research paper, but the numerical results, graphs and tables are model/simulated data and must be replaced with validated laboratory findings before publication.
The proposed formulation showed a model mean hydrodynamic diameter of 178.4 +/- 16.7 nm, polydispersity index of 0.21 +/- 0.04, zeta potential of +31.8 +/- 3.2 mV, doxycycline encapsulation efficiency of 76.9 +/- 2.6% and cefixime encapsulation efficiency of 69.4 +/- 3.1%. In simulated susceptibility outputs, dual-loaded nanoparticles reduced the model minimum inhibitory concentration from 16 ug/mL for doxycycline and 32 ug/mL for cefixime to 2 ug/mL combined-drug equivalent, while the mean inhibition zone increased to 29 +/- 2 mm against a representative MDR S. Typhi panel. Release modelling suggested a biphasic profile with an initial surface-associated release followed by sustained liberation through polymer swelling and erosion. These results support the hypothesis that dual-loaded biodegradable nanoparticles may intensify antibacterial activity through spatial co-delivery, membrane interaction and complementary antibiotic stress.
How to Cite
Dakshita, Rakesh Kumar, "In-Vitro Evaluation of Doxycycline–Cefixime Nanoparticles against MDR S. Typhi", Vol. 3, Issue 3, 28-06-2025, pp. 114-129.
