Research findings
No. 28 The Sustained Release of Salicylic Aldehyde by Chemically Modified Cyclodextrins
Salicylic aldehyde (SA) is useful as an insect repellent1).
![](img/research_e_028_01.png)
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
![](img/research_e_028_02.png)
![](img/research_e_028_03.png)
Conclusions
Confected clathrate included about 6~9% of SA.
Sustained release of SA-CD complexes
![](img/research_e_028_04.png)
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.