Crystallization of neomycin nanoparticles in the presence of polyvinyl pyrrolidone (PVP)

Neomycin nanoparticles were prepared using the inductive crystallization method in the presence of polyvinylpyrrolidone (PVP) as a stabilizer. Given the favorable solubility of neomycin in water, distilled water was used as the solvent. In addition, acetone was utilized as the antisolvent due to its high polarity and good solubility in water. The produced neomycin nanoparticles were characterized by various analyses such as TEM, HR-TEM, SEM, FE-SEM, FT-IR, XRD, DSC, TGA, AFM, DLS, and EDX. The DLS analysis indicated a bimodal size distribution from 17 to 235 nm. The induction time and nucleation mechanism were also determined. The results showed that the primary nucleation mechanism was the prevailing process, as validated by the higher R² values. The potential role of PVP as a stabilizing agent influenced the crystallization of neomycin nanoparticles and prevented crystal aggregation, as well as favorably changing the surface tension and solubility. It was also observed that the mixing speed can affect the induction time and thus the optimal speed was set to 300 rpm. Additionally, the effect of solvent–antisolvent ratios on solubility was examined, demonstrating that higher supersaturation leads to decreased solubility of neomycin in acetone–water mixtures. Finally, the ternary diagram or two-phase nucleation related to Metastable Zone Width (MSZW) was determined.