



@article {3281,
	title = {Stability study perspective of the effect of freeze-drying using cryoprotectants on the structure of insulin loaded into PLGA nanoparticles},
	journal = {Biomacromolecules},
	volume = {15},
	year = {2014},
	note = {Export Date: 21 November 2014},
	month = {2014},
	pages = {3753 - 3765},
	abstract = {This work aimed to evaluate the influence of a freeze-drying process using different cryoprotectants on the structure of insulin loaded into poly(lactic-co-glycolic acid) (PLGA) nanoparticles and to assess the stability of these nanoparticles upon 6 months of storage following ICH guidelines. Insulin-loaded PLGA nanoparticles with a size around 450 nm were dehydrated using a standard freeze-drying cycle, using trehalose, glucose, sucrose, fructose, and sorbitol at 10\% (w/v) as cryoprotectants. All formulations, except those nonadded of cryoprotectant and added with trehalose, collapsed after freeze-drying. The addition of cryoprotectants increased the nanoparticles stability upon storage. FTIR results showed that insulin maintained its structure after encapsulation in about 88\%, decreasing to 71\% after freeze-drying. The addition of cryoprotectants prior to freeze-drying increased insulin structural stability an average of up to 79\%. Formulations collapsed after freeze-drying showed better protein stabilization upon storage, in special sorbitol added formulation, preserving 76, 80, and 78\% of insulin structure at 4 {\textdegree}C, 25 {\textdegree}C/60\% RH, and 40 {\textdegree}C/75\% RH, respectively. Principal component analysis also showed that the sorbitol-added formulation showed the most similar insulin structural modifications among the tested storage conditions. These findings suggested that regarding nanoparticles stability, cryoprotectants are versatile to be used in a standard freeze-drying, however they present different performances on the stabilization of the loaded protein. Thus, on the freeze-drying of the nanoparticles field, this work gives rise to the importance of the process of optimization, searching for a balance between a good obtainable cake with an optimal structural stabilization of the loaded protein.},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84907968489\&partnerID=40\&md5=15b0a74cf97f04ed887f86b7ad1c45a2},
	author = {Fonte, P. and Soares, S. and Sousa, F. and Costa, A. and Seabra, V. and Reis, S. and Sarmento, B.}
}
@article {2845,
	title = {Effect of freeze-drying, cryoprotectants and storage conditions on the stability of secondary structure of insulin-loaded solid lipid nanoparticles},
	journal = {International Journal of Pharmaceutics},
	volume = {456},
	year = {2013},
	note = {Export Date: 12 December 2013Source: Scopus},
	month = {2013///},
	pages = {370 - 381},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84886730036\&partnerID=40\&md5=2214d57803df6679f944d2ebba4fa477},
	author = {Soares, S. and Fonte, P. and Costa, A. and Andrade, J. and Seabra, V. and Ferreira, D. and Reis, S. and Sarmento, B.}
}
