Zeta potential for all formulations was determined and tabulated in Table IV as observed values. Figure 2 b showed the graphical presentation of zeta potential measurement for 17 formulations. The zeta potential ranged from + 20.77 ± 5.59 to + 50.47 47 ± 1.65 mV. The zeta potential was mainly determined by lecithin and chitosan used. However, PEG 2000 as a polymer grafting on the lecithin-chitosan core-shell structure might be impacting the stability of the nanoparticle. The values can be used as an indicator that all the prepared hybrid nanoparticle formulations were highly stable. Using Design-Expert software, the relationship between the used amount of lecithin, chitosan, and PEG 2000 on zeta potential can be explained using Eq. (10) with a high R2 value of 0.9294.10 Y2=28.09–3.57X1+8.68X2–7.16X3+0.42X1X2+1.83X1X3+2.08X2X3+1.51X12+6.7X22+1.84X32