The purpose of this study was to develop and characterize insulin nanoparticles systems using chitosan. Insulin-loaded nanoparticles were prepared by ionic gelation of chitosan with tripolyphosphate anions (TPP). The interactions between insulin and chitosan were evaluated by differential scanning calorimetry (DSC), thermogravimetry/derivative thermogravimetry (TG/DTG), and Fourier-transform infrared (FTIR) spectroscopy. Besides, particle size distribution, polydispersity index (PDI), zeta potential, and association efficiency (AE%) of the nanoparticles were evaluated. In general, inert nanoparticles and insulin-loaded nanoparticles showed an average size of 260.56 nm (PDI 0.502) and 312.80 nm (PDI 0.481), respectively. Both nanoparticles showed positive charge, but after insulin incorporation the zeta potential was reduced, evidencing its incorporation. Nanoparticles obtained also showed AE% around 70%, measured by high-performance liquid chromatography (HPLC). The results of FTIR, DSC, and TG/DTG corroborated the data presented suggesting that insulin was successfully encapsulated. However, drug incorporation seems to be related not only to electrostatic interactions, but also to physical process and/or adsorption phenomena.
1. Janes, KA, Fresneau, MP, Marazuela, A, Fabra, A, Alonso, MJ. Chitosan nanoparticles as delivery systems for doxorubicin. J Control Release. 2001;73:255–267. .
2. Calvo, P, Remunan-Lopez, C, Vila-Jato, JL, Alonso, MJ. Chitosan and chitosan/ethylene oxide–propylene oxide block copolymer nanoparticles as novel carriers for proteins and vaccines. Pharm Res. 1997;14:1431–1436. .
3. Ko, JA, Park, HJ, Hwang, SJ, Park, JB, Lee, JS. Preparation and characterization of chitosan microparticles intended for controlled drug delivery. Int J Pharm. 2002;249:165–174. .
4. Kumari, K, Raina, KK, Kundu, PP. DSC studies on the curing kinetics of chitosan–alanine using glutaraldehyde as crosslinker. J Therm Anal Calorim. 2009;98:469–476. .
5. Ajun, W, Yan, S, Li, G, Huili, L. Preparation of aspirin and probucol in combination loaded chitosan nanoparticles and in vitro release study. Carbohydr Polym. 2009;75:566–574. .
6. Barichello, JM, Morishita, M, Takayama, K, Nagai, T. Absorption of insulin from Pluronic F-127 gels following subcutaneous administration in rats. Int J Pharm. 1999;184:189–198. .
7. Mesiha, MS, Sidhom, MB, Fasipe, B. Oral and subcutaneous absorption of insulin poly(isobutylcyanoacrylate) nanoparticles. Int J Pharm. 2005;288:289–293. .
8. Ramachandran, R, Paul, W, Sharma, CP. Synthesis and characterization of PEGylated calcium phosphate nanoparticles for oral insulin delivery. J Biomed Mater Res B Appl Biomater. 2009;88:41–48.
9. Fernández-Urrusuno, R, Calvo, P, Remuñán-López, C, Vila-Jato, JL, Alonso, MJ. Enhancement of nasal absorption of insulin using chitosan nanoparticles. Pharm Res. 1999;16:1576–1581. .
10. Pan, Y, Li, YJ, Zhao, HY, Zheng, JM, Xu, H, Wei, G, Hao, JS, Cui, FD. Bioadhesive polysaccharide in protein delivery system: chitosan nanoparticles improve the intestinal absorption of insulin in vivo. Int J Pharm. 2002;249:139–147. .
11. Ma, Z, Lim, TM, Lim, LY. Pharmacological activity of peroral chitosan-insulin nanoparticles in diabetic rats. Int J Pharm. 2005;293:271–280. .
12. Sarmento, B, Ribeiro, A, Veiga, F, Sampaio, P, Neufeld, R, Ferreira, D. Alginate/chitosan nanoparticles are effective for oral insulin delivery. Pharm Res. 2007;24:2198–2206. .
13. Sarmento, B, Ferreira, D, Veiga, F, Ribeiro, A. Characterization of insulin-loaded alginate nanoparticles produced by ionotropic pre-gelation through DSC and FTIR studies. Carbohydr Polym. 2006;66:1–7. .
14. Ma, Z, Yeoh, HH, Lim, LY. Formulation pH modulates the interaction of insulin with chitosan nanoparticles. J Pharm Sci. 2002;91:1396–1404. .
15. Bayat, A, Dorkoosh, FA, Dehpour, AR, Moezi, L, Larijani, B, Junginger, HE, Rafiee-Tehrani, M. Nanoparticles of quaternized chitosan derivatives as carrier for colon delivery of insulin: ex vivo and in vivo studies. Int J Pharm. 2008;356:59–60. .
16. Gan, Q, Wang, T, Cochrane, C, McCarron, P. Modulation of surface charge, particle size and morphological properties of chitosan-TPP nanoparticles intended for gene delivery. Colloids Surf B Biointerfaces. 2005;44:65–73. .
17. Santos, JE, Soares, JP, Dockal, ER, Campana Filho, SP, Cavalheiro, ETG. Caracterização de quitosanas comerciais de diferentes origens. Polím Ciên Tecnol. 2002;13:242–249.
18. Peniche, C, Elvira, C, Roman, JS. Interpolymer complexes of chitosan and poly-methacrylic derivatives of salicylic acid: preparation, characterization and modification by thermal treatment. Polymer. 1998;34:6549–6554. .
19. Boonsongrit, Y, Mueller, BW, Mitrevej, A. Characterization of drug–chitosan interaction by 1H NMR, FTIR and isothermal titration calorimetry. Eur J Pharm Biopharm. 2008;69:388–395. .
20. Sarmento, B, Ribeiro, A, Veiga, F, Ferreira, D. Development and characterization of new insulin containing polysaccharide nanoparticles. Colloids Surf B Biointerfaces. 2006;53:193–202. .
21. Bhumkar DR , Pokharkar VB. Studies on effect of pH on cross-linking of chitosan with sodium tripolyphosphate: a technical note. AAPS PharmSciTech. 2006;7:1–6. http://www.aapspharmscitech.org.
22. Xu, Y, Du, Y. Effect of molecular structure of chitosan on protein delivery properties of chitosan nanoparticles. Int J Pharm. 2003;250:215–226. .
23. Pikal, MJ, Rigsbee, DR. The stability of insulin in crystalline and amorphous solids: observation of greater stability for the amorphous form. Pharm Res. 1997;14:1379–1387. .
24. Lai, MC, Topp, EM. Solid-state chemical stability of proteins and peptides. J Pharm Sci. 1999;88:489–499. .
25. Boonsongrit, Y, Mitrevej, A, Mueller, BW. Chitosan drug binding ionic interaction. Eur J Pharm Biopharm. 2006;62:267–274. .