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Journal of Drug Delivery
Volume 2017 (2017), Article ID 4875784, 9 pages
Research Article

Preparation, Characterization, and In Vivo Pharmacoscintigraphy Evaluation of an Intestinal Release Delivery System of Prussian Blue for Decorporation of Cesium and Thallium

1Department of Nuclear Medicine, Institute of Nuclear Medicine and Allied Sciences, Defence R&D Organisation, Brig. SK Mazumdar Road, Delhi 110 054, India
2Division of Pharmaceutical Chemistry, DIPSAR, MB Road, Pushp Vihar, New Delhi 110 017, India

Correspondence should be addressed to Gaurav Mittal

Received 9 August 2017; Revised 2 November 2017; Accepted 12 November 2017; Published 29 November 2017

Academic Editor: Ali Nokhodchi

Copyright © 2017 Nidhi Sandal et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. Prussian blue (PB, ferric hexacyanoferrate) is approved by US-FDA for internal decorporation of Cesium-137 (137Cs) and Thallium-201 (201Tl). Aim. Since PB is a costly drug, pH-dependent oral delivery system of PB was developed using calcium alginate matrix system. Methods. Alginate (Alg) beads containing PB were optimized by gelation of sodium alginate with calcium ions and effect of varying polymer concentration on encapsulation efficiency and release profile was investigated. Scanning electron microscopy (SEM) was carried out to study surface morphology. Adsorption efficacy of Alg-PB beads for 201Tl was evaluated and compared with native PB. In vivo pH-dependent release of the formulation was studied in humans using gamma scintigraphy. Results. Encapsulation efficiencies of Alg-PB beads with 0.5, 1.0, 1.5, and 2.0% polymer solution were 99.9, 91, 92, and 93%, respectively. SEM and particle size analysis revealed differences between formulations in their appearance and size distribution. No drug release was seen in acidic media (pH of 1-2) while complete release was observed at pH of 6.8. Dissolution data was fitted to various mathematical models and beads were found to follow Hixson-Crowell mechanism of release. The pH-dependent release of beads was confirmed in vivo by pharmacoscintigraphy in humans.