Tailoring Doxorubicin sustainable release from biopolymeric smart matrix by Congo Red as molecular helper

V. E. BOSIO; A.G. LOPEZ ; A. MUKHERJEE; M. MECHETTI ; G.R. CASTRO

JOURNAL OF MATERIALS CHEMISTRY B

Royal Chemical Society

Año: 2014 vol. 2 p. 5178 - 5186

2050-750X

Doxorubicin (Dox) was co-encapsulated with Congo Red (CR) in order to increase drug encapsulation and sustain the release from gel microbeads composed of Alginate-Carboxy Methyl Guar Gum (68/32) for oral controlled delivery. No release of both cargo molecules from the microbeads at pH 1.2 in 90 minutes was detected. However, 62 % CR and 16 % Dox were released from the gels at pH 7.4 at 37 °C in 8 hours when both the cargo molecules are alone. Presence of CR in the formulation reduces in about 25-30 % the release of Dox under the same experimental conditions. Rheological properties of the formulations have been investigated at different temperatures between 20 and 37 ºC. Shear thinning behavior was observed by steady-shear flow experiments for all of them and no yield stress was observed for any of the formulations. The temperature effect on Alg-CMGG-Dox-CR evidenced a synergic action between Dox and CR. Dynamic frequency sweep tests were performed to study the viscoelastic properties of the formulations. The patterns observed for Alg-CMGG indicated physical gel characteristics; however all other formulations showed a typical behavior of concentrated solutions. These results are confirming the interaction of Dox and CR and the positive effect on sustainable release in oral delivery.