13 ± 0.47, 13.71 ± 0.53, and 9.37 ± 0.36 for OCM-CS:CaCl2 weight ratio

6:1, 5:1, and 4:1, respectively, (Table 6). OCM-CSNPs were formed due to ionic interactions between OCM-CS, CaCl2, and DRZ. As the concentration of OCM-CS Tideglusib purchase increased from 4:1 to 6:1, entrapment efficiency also increased owing to availability of larger number of negatively charged COO− group that interacted with positively charged NH3+ of DRZ. The amount of CaCl2 required for ionic gelation of OCM-CS containing DRZ was less than that required for plain OCM-CS solution. This indicates that the binding affinity of CaCl2 towards OCM-CS in presence of DRZ was reduced. For CSNPs, entrapment efficiency was found to be 20.08 ± 0.87, 16.29 ± 0.61, and 10.51 ± 0.57, Inhibitors,research,lifescience,medical respectively, for 6:1, 5:1, and 4:1 for CS:TPP weight ratio (Table 7). In this case, there was no ionic interaction (only weak electrostatic interaction) between CS and DRZ (both positively charged at pH 5.5)

but negatively charged polyanionic TPP could interact with Inhibitors,research,lifescience,medical cationic CS and preferentially with protonated DRZ. Therefore, with increased concentration of TPP in CS:TPP weight ratio from 6:1 to 4:1, the amount of DRZ available for physical entrapment with CS decreased resulting in decreased entrapment. Similar results were obtained by Singh et al. for Inhibitors,research,lifescience,medical CSNPs of brimonidine tartrate which is also protonated at the same pH [36]. Therefore, CS:TPP weight ratio 6:1, with minimum amount of TPP resulted in the highest entrapment [20]. 3.11. Effect of Drug Loading on Particle Size, Zeta Potential, and Entrapment Efficiency The OCM-CS:CaCl2 and CS:TPP weight ratios were loaded with a different polymer: DRZ and the effect on particle size, PI, zeta potential, and entrapment efficiency was studied (Table 8). For OCM-CSNPs, Inhibitors,research,lifescience,medical particle size increased with increased DRZ loading. The mean particle size varied from 181.1 ± 2.721 to 239.6 ± 3.811nm with PI ranging from 0.209 ± 0.081 to 0.316 ± 0.029. The negative zeta

potential values changed from −31.24 ± 0.75 to −24.03 ± 0.68 as the concentration of DRZ increased. These results demonstrated Inhibitors,research,lifescience,medical that the incorporation of the DRZ into OCM-CSNPs led to a drug proportion-dependent increase of their size compared with blank NPs (Figure 5). Increased drug proportion caused an increased reduction of OCM-CS:CaCl2 interaction, leading to increase NPs size [37], whereas no significant change in the particle size of CSNPs was observed as the drug loading Liothyronine Sodium was increased. The mean particle size was found to be in the range of 250.3 ± 2.627nm with PI 0.313 ± 0.009 (Figure 6). Zeta potential values showed moderate to good stability (+28.61 ± 0.924 to +33.89 ± 0.547). These narrow particle size distributions with low PI and moderate zeta potential values attributed to stability of OCM-CS and CS NPs [38]. Figure 5 Effect of drug loading on OCM-CS:CaCl2 weight ratio of 6:1. Values are expressed as mean ± standard deviation, n = 3.