*3.6. Encapsulation Efficiency and Loading Capacity*

The encapsulation efficiency (EE) percentage and the loading capacity (LC) percentage of all three loaded nanoforms are shown in Table 2. A concentration-dependent pattern in the EE (%) and non-concentration-dependent increase in the percentage LC of mancozebloaded CSGA-conjugated nanoparticles was observed. Minimum and maximum EEs recorded were 15.95 ± 0.25 and 57.13 ± 0.29 for the formulations CSGA-0.5 and CSGA-1.5, respectively, with LC of 76.25 ± 0.26%, which might be due to excess mancozeb in the CSGA-1.5 sample [35]. Maximum LC (81.10 ± 0.18) was found for NPs containing 1.0 mg/mL mancozeb sample with optimum fungicide available for loading; results of the present study followed an earlier study [23,36].

**Table 2.** Mancozeb encapsulation and loading capacity of CSGA NPs.


Mean ± standard deviation in replication of three.

#### *3.7. Controlled Release Behavior*

The drug release from the conjugated nanoparticles was time-dependent and sustainedrelease owing to diffusion (Figure 4). The commercial fungicide released 100% within two hours, while NPs containing 0.5 mg/mL mancozeb (CSGA-0.5) had the best release mechanisms within 8 h, releasing 64% of total mancozeb content, while CSGA-1.5 formulation released 81% of total mancozeb content for the same time [37]. Because the active component of mancozeb is confined in the center of the polymer core, the release rate of nanoform is slower than that of commercial mancozeb [38,39]. Compared to commercial fungicides, this in vitro gradual release of NPs boosts plant absorption, reduces soil leaching, and reduces soil and water pollution. In a comparative investigation, the cumulative release

percentage for carbendazim-loaded NPs was 50.4 ± 0.13 percent, compared to 67.7 ± 0.1% for pure carbendazim at pH 7.4 [40]. Another researcher [26] used an ionic gelation approach to collect marketable hexaconazole in chitosan NPs and obtained a sustained release of 99.91% over 86 h. There may be some chemical bonding between chitosan, gum, and fungicide as the polymers are oppositely charged, and fungicides also have both positive and negative charges, enhancing the release time. This enhanced interaction was also seen as a biocidal additive in paints and coatings [41].

**Figure 4.** In vitro sustain release of mancozeb from chitosan–gum acacia-conjugated nanoparticles (CSGA). The yellow line represents commercial fungicide, while blue, saffron, and gray represent CSGA-0.5, 1.0, and 1.5, respectively.
