Formulation and characterization of Caesalpinia decapetala seed oil nanoemulsion: physicochemical properties, stability, and antibacterial activity

Nanoemulsions contain acceptable O/W or W/O dispersions, with droplet sizes ranging from 100 to 500 nm. In the current study, we formulated O/W nanoemulsion using Caesalpinia decapetala seed oil, Tween 20, and Tween 80 surfactant through ultrasonic and spontaneous emulsification. C. decapetala is a climbing shrub thorny tree. C. decapetala seed oil contains different chemical constituents. As a result, physicochemical properties of prepared nanoemulsion came to be 132.561 ± 0.491-290.033 ± 1.952 nm average particle size, 0.028 ± 0.038-0.301 ± 0.042 polydispersive index, -32.274 to -58 mV zeta potentials, 4.383-6.5 pH value, 3.922-5.247 mPa.s viscosity value with spherical shape, with excellent physical stability. Subsequently, gram-positive and gram-negative bacterial strains were employed to assess the nanoemulsion's antibacterial efficacy. Therefore, the results indicate that C. decapetala seed oil nanoemulsion has excellent antibacterial activity on gram-positive and gram-negative bacteria strains. This nanoemulsion formulated using Tween 80 had higher inhibition zones like 13.5,13, 12, and 11 mm than the other methods on S. aureus, E.coli, S.pyogenes, and P. aeruginosa, respectively. Generally, smaller particle size, polydispersive index, stable surface charge, and low value of viscosity indicate that formulated nanoemulsion had better stability and bioavailability activity for antibacterial activity.