## 5 Conclusions  
In conclusion, the results of the formation of Eudragit(r) polymer nanoparticles via the nanoprecipitation method confirmed that S, PDI, and homogeneity are directly related to the fundamental variables of the technique. This comparative study allowed us to choose, in a simple way, the appropriate combination for the formulation of NPs with a defined particle size in the range of 70 to 230 nm and to reproduce it using methacrylic acid-derived polymers with highly homogeneous particle size populations. The PVA in the aqueous phase increased the encapsulation rate of Qr in the PNPs; thus, in this research, a methodology for the adequate encapsulation of flavonoids such as Qr was achieved, as well as the formation of homogeneous PNPs with spherical morphology.  
A methodology was developed for the efficient nanoencapsulation of non-water-soluble biomolecules, such as the flavonoid quercetin, employing the nanoprecipitation technique and using Eudragit(r) polymers for pharmaceutical use. These data are intended to provide an approach for the future administration of this type of molecule for various uses, such as pharmaceuticals. As a perspective, the results encourage future studies involving the use of nanoencapsulation of products for their administration and show the need for further studies to evaluate their toxicity in mammalian cells.  
The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/app13137816/s1](https://www.mdpi.com/article/10.3390/app13137816/s1)]([https://www.mdpi.com/article/10.3390/app13137816/s1](https://www.mdpi.com/article/10.3390/app13137816/s1)): Table S1. The average size of nanoparticles (PNPs) and polydispersity index (PDI) prepared by the nanoprecipitation technique in different concentrations of the organic phase (OP), aqueous phase (AP), and polymer amount (PA) using different Eudragit(r) polymers; informed consent form; Institutional Review Board Approval CI-06-19-2023.  
Conceptualization, R.C.-R.; methodology, H.L.-G. and M.G.-T.; validation, R.C.-R.; formal analysis and investigation, J.H.E.-L.; data curation, H.L.-G.; writing--original draft preparation, J.H.E.-L.; writing--review and editing, J.H.E.-L., E.M.M.-M. and A.C.-M.; visualization, M.G.-T.; supervision, R.P.-S. and A.C.-M.; project administration, M.G.-T. and A.C.-M.; funding acquisition, E.M.M.-M. and R.P.-S. All authors have read and agreed to the published version of the manuscript.  
**Funding:** The authors thank the Tecnologico de Monterrey for their support in the APC of this research.  
**Institutional Review Board Statement:** All procedures were approved by the institutional research ethics committee and performed by the recommendations of the Declaration of Helsinki on biomedical research involving human subjects.  
**Informed Consent Statement:** The study with human erythrocytes was conducted according to and approved by the Ethics Committee of the UANL, registration number CI-06-19-2023. The letter of Informed Consent for donors of human biological sample material and the Institutional Review Board Approval are attached as Supplementary Materials.  
**Data Availability Statement:** Not applicable.  
**Acknowledgments:** We are grateful to Tecnologico de Monterrey for financial support for the publication of this research. The authors appreciate the support from USAL for the literature services.  
**Conflicts of Interest:** The authors declare no conflict of interest.