Exploring the potential of Dimorphandra gardneriana galactomannans as drug delivery systems

Galactomannans represent one of the most versatile classes of available materials for applications in many sectors, including pharmaceuticals. Galactomannans have gained attention in the latest years for applications in drug release systems. In this work, a previously extracted and purified galactomannan from Dimorphandra gardneriana (Tul.) was modified by sulfation reaction. The sulfation reaction was effective to modify the galactomannan D. gardneriana resulting in a substitution degree of 0.61. Galactomannan from D. gardneriana (GLMDg) and its sulfated derivative (GLMDgS) were used as polymeric matrices for mangiferin encapsulation by spray-drying process. The efficiency of the different matrices for drug release was studied comparing the dissolution profile of the mixtures: mangiferin/(GLMDg) and mangiferin/(GLMDgS) in pH 1.2, 4.6 and 6.8 buffer solutions, simulating gastric and intestinal media at 37 degrees C. The fattest release profile was found to be for the sulfated polymeric matrix. The faster release profile of the sulfated polymeric matrix (release rate, approximately 100% after 8 h) when compared to the natural polymer (82.7%) was due to the reduction of the molar mass and viscosities of the sulfated galactomannan caused by the depletion of the polymer during sulfation. The results show the potential of GLMDg and GLMDgS as bio-based drug delivery system for the controlled release of bioactives. (C) 2015 Elsevier B.V. All rights reserved.