Recent research finding
No.18 Improvement of stability of iodine by cyclodextrin

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Summary

Stabilization of iodine by cyclodextrin
The iodine-based synthesized agents are well known to show the strong and broad spectrum anti-microbial activities, and have widely used as anti-bacterial, anti-fugal and anti-virus agents in the medical or agricultural fields.
These agents shows the release characteristics by containing iodine atom in their molecule. On the other hand, there is an iodine agent "iodophor" to have the similar functions.

The weak point of iodophor
An Iodophor is an iodine complex with a carrier compound like a synthesized polymer or surface-active agent, and the safety evaluation for humans is shown to be comparably high. However, the performance of release characteristics and long term stability as an anti-microbial agent are usually lower then those of iodine-based synthesized agent. Therefore, we reported the improvement of stability of iodophors using cyclodextrin.

Evaluation of release characteristics of cylclodextrin-iodine complex (CDI)
The release characteristics of CDI powder (available iodine content = 20%, 10% and 5%) was evaluated by the mass change at constant temperatures and humidity. After reaching the equilibrium moisture content of CDI, the decrease of the mass change was not observed at 23℃ for 400 h. On the other hand, at 60℃, the decrease of the available iodine content of CDI was less than 10% for 400 h. These results mean that CDI is really stable at 23℃ and shows suitable release characteristics at 60℃.

Release rate of iodine in CDI on constant temperature and humidity evaluated by mass change

Release rate of iodine in CDI on constant temperature and humidity evaluated by mass change

Conclusions

The stability of iodine was markedly improve to be included in cyclodextrin.
The production of CDI is now carried out in the industrial level due to the excellent stability of CDI.