The EDS analysis as a tool for the coating evaluation of microcapsules

This work aimed to evaluate the use of EDS analysis in the control of the coating of microcapsules prepared by coacervation. Ethylcellulose was the coating material and sulfadiazine was the capsule core. As the sulfur atom is not contained in the ethylcellulose molecule but only in the drug molecule, clearly the EDS emission of sulfur can be merely considered the evidence of the microcapsule core. The results of the analysis show a decrease in the intensity of the EDS emission from the microcapsule core respect to the emission intensity from the uncoated drug crystals. Furthermore, the emission intensity decrease as the wall thickness increases.The EDS analysis could be therefore useful for the technological control of the actual drug microencapsulation and the batch to batch reproductibility of the wall thickness.