Physical properties of pectin-high amylose starch mixtures cross-linked with sodium trimetaphosphate

Autor(es)

Carbinatto, Fernanda M. ^[1] ; de Castro, Ana Doris ^[1] ; Cury, Beatriz S. F. ^[1] ; Magalhaes, Alvicler ^[2] ; Evangelista, Raul C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista UNESP, Fac Ciencias Farmaceut, Dept Farmacos & Medicamentos, BR-14801902 Araraquara, SP - Brazil

^[2] Univ Estadual Campinas UNICAMP, Inst Quim, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: International Journal of Pharmaceutics; v. 423, n. 2, p. 281-288, FEB 28 2012.
• Citações Web of Science: 35

Resumo

Pectin-high amylose starch mixtures (1:4; 1:1; 4:1) were cross-linked at different degrees and characterized by rheological, thermal, X-ray diffraction and NMR analyses. For comparison, samples without cross-linker addition were also prepared and characterized. Although all samples behaved as gels, the results evidenced that the phosphorylation reaction promotes the network strengthening, resulting in covalent gels (highest critical stress, G' and recovery %). Likewise, cross-linked samples presented the highest thermal stability. However, alkaline treatment without cross-linker allowed a structural reorganization of samples, as they also behaved as covalent gels, but weaker than those gels from cross-linked samples, and presented higher thermal stability than the physical mixtures. X-ray diffractograms also evidenced the occurrence of physical and chemical modifications due to the cross-linking process and indicated that samples without cross-linker underwent some structural reorganization, resulting in a decrease of crystallinity. The chemical shift of resonance signals corroborates the occurrence of structural modifications by both alkaline treatment and cross-linking reaction. (C) 2011 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 08/01901-3 - Matrizes poliméricas de alta amilose e pectina reticuladas para liberação controlada de nimesulida
• Beneficiário: Fernanda Mansano Carbinatto
• Modalidade de apoio: Bolsas no Brasil - Mestrado