No. 28 The Sustained Release of Salicylic Aldehyde by Chemically Modified Cyclodextrins

Salicylic aldehyde (SA) is useful as an insect repellent1).

With the aim of the tractability improvement of the liquid and volatile SA, the inclusion complexes with randomly methylated cyclodextrins (RM-CDs, DS = 1.8) and hydroxyl propyl CDs (HP-CDs, DS = 0.4) were prepared according to kneading method and their sustained releases were investigated.

1) Shimada et al., An insect repellent of lepidopteran., Patent gazette 2006-206519.

Actual SA content

Conclusions
Confected clathrate included about 6~9% of SA.

Sustained release of SA-CD complexes

Conclusions

• RM-CDs, HP-CDs in each case, SA-CD powder could confect.
• Release rates of SA from the complexes were increased in the following order: RM-alpha-CD < RM-beta-CD = RM-gamma-CD < HP-gamma-CD = HP-beta-CD < HP-alpha-CD.
• Release of SA speedily HP-CDs than RM-CDs.