An in situ crosslinked compression coat comprised of pectin and calcium chloride for colon-specific delivery of indomethacin

Abstract

The use of pectin for colon-specific drug delivery has been extensively investigated; however, when used alone, pectin is often compromised due to its high solubility. This study explored the feasibility of using an in situ compression-coated crosslinking system, composed of pectin and calcium chloride, for colon-specific drug delivery. A pectin/calcium chloride (P/Ca) coating was compressed onto a core tablet. The colon specificity of the compression-coated tablet was verified by dissolution, pharmacokinetics and scintigraphy with ^99mTc labeling. The in situ pectin and calcium chloride gel slowed the release of indomethacin. The lag time varied between 3 h and 7 h depending on the amount of calcium chloride and the coating weight. Pectinase triggered the release of indomethacin from the compression-coated tablet, which was then accelerated by the calcium chloride in the coating layer. The compression-coated tablet had a prolonged t_max and apparent t_1/2, as well as a decreased C_max and AUC_0–t, compared with the core tablet counterpart. Evaluation with γ-scintigraphy verified colon-specific delivery of the compression-coated tablet. In conclusion, the P/Ca in situ crosslinking system worked well for colon-specific drug delivery.

• Calcium chloride
• colon
• compression coated
• indomethacin
• in situ crosslinking
• pectin
• tablet

Acknowledgements

We thank Professor Jianhua Zhu for his assistance in scintigraphic evaluation. Dr. Wu would like to thank the Shanghai Commission of Education (10SG05) and Ministry of Education (NCET-11-0114) for personnel fostering funding.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

This work was partly supported by Shanghai Municipal Commission of Science and Technology (11DZ1920200 and 11DZ1920906).