Nanoencapsulation of ofloxacin using sesame seed oil-based colloidal system: antimicrobial, toxicity, and drug delivery studies

Abstract

Hydrophobicity and gastroenzymatic degradation of drugs necessitated an innovative approach, which is the adoption of a nanosized colloidal system for drug delivery. The emulsions were produced by the mechano-chemical method and characterized using FTIR, UV-Vis spectroscopy, Zetasizer, 1HNMR, and Cryo-TEM. Molecular studies and antimicrobial activity of Sesame oil-based nanoemulsion (SOBN), Ofloxacin-loaded Sesame oil-based nanoemulsion (SOBN+OF), and Ofloxacin (OF) were carried out on S. aureus , K. pneumoniae , S. aureus (ATCC 29213), and P. aeruginosa (ATCC 15442). Drug delivery studies of SOBN+OF were done using adult male Wistar rats. The Zeta potential measurement shows a negatively charged emulsion (-16.1 mV), with low Poly Dispersity Index (PDI) values, which suggests high stability. The Cryo-TEM micrographs show a rough spherical colloid with an average diameter of 610.4±0.54 nm and an effective Electric Field Strength (EFS) value of 147.4 V. The UV-Vis analysis recorded a maximum drug entrapment efficiency of 21.250 μg/mL. The FTIR shows a superimposition of SOBN and SOBN+OF spectra with a wavenumber value of 3427.76 cm −1 , which is in agreement with the 1HNMR results, suggesting an encapsulation. The molecular studies show that the highest docking values of -6.67291594 and -7.09475231 were recorded on peptidoglycan deacetylase (gram-positive) and beta-lactamase class A (gram-negative) bacterium protein, respectively. The antimicrobial study shows that SOBN+OF is more potent than OF across a concentration range of 500 to 31.25 mg/mL. The toxicity of the investigated dosage (17.5 mL/kg bw) of SOBN+OF has a pathomorphological effect on Wistar rats. The HPLC shows that. SOBN+OF-treated rat skin showed a measured absorption value of 0.0980 μg/mL, indicating a significant penetration rate. A recorded C max value of 2.31 μg/mL was noted at 150 min in the transdermo-pharmaceuical study. The outcome of this study shows that Sesame oil-based nanoemulsion is a probable vehicle, with the potential to encapsulate, transport, and release ofloxacin, thereby enhancing its biopotency. • Synthesis of a novel metastable, negatively charged sesame oil-based nanoemulsion (SOBN+OF) for improved encapsulation and transport of hydrophobic ofloxacin. • SOBN+OF achieved a maximum entrapment efficiency of 21.25 μg/mL, with UV-Vis and FTIR spectra supporting successful drug loading. • Emulsions were rigorously analyzed using FTIR, UV-Vis, 1 H-NMR, Zetasizer, and Cryo-TEM, confirming encapsulation, stability, and nanoscale morphology. • Molecular docking validates strong interactions with bacterial targets, with high docking affinities on peptidoglycan deacetylase (-6.67 kcal/mol) and beta-lactamase class A (-7.09 kcal/mol). • SOBN+OF outperformed pure ofloxacin against both standard and clinical strains of S. aureus , K. pneumoniae , and P. aeruginosa over a wide concentration range. • Transdermal studies in Wistar rats revealed a notable C max of 2.31 μg/mL at 150 minutes, with measurable dermal absorption, validating its pharmacokinetic potential.