Design and characterization of protein-based microcapsules as a novel catamenial absorbent system

Hollow and flexible crosslinked microcapsules of soybean protein, 150-300 μm in diameter, were produced using a modified solvent evaporation method. A maximum plasma absorption of approximately 2000% was obtained. At this swelling rate though, microcapsules bursting was initiated. Thus, the effective absorption capacity may not exceed 1700%. The observed presence of residual unreacted protein inside the microcapsules, was believed to be the main osmotic driving force, to which the extensive swelling and eventual bursting of the microcapsules may be attributed. Thermal analysis of the microcapsules revealed their amorphous nature, as opposed to the significantly crystalline nature of the original protein.