Study on Encapsulation of Diethyl Phenyl Acetamide in Calcium-Alginate Microsphere for Enhanced Repellent Efficacy

Abstract

In this present study, diethyl phenyl acetamide (DEPA), a multi-insect repellent, was entrapped in a hydrophilic biodegradable polymer calcium alginate to increase its efficacy. For encapsulation, an emulsion technique followed by gelation method was adopted. Various characterizations of the formed DEPA-containing alginate microcapsules were carried out. Using UV-Vis spectrophotometer the λ_max of DEPA observed was at 259 nm. The particle size distribution of the encapsulated material was carried out by a dynamic light scattering (DLS) method and the mean diameter observed was (500 ± 50) nm. The entrapment of DEPA in the encapsulated material was confirmed by FTIR. The surface morphology, size, and shape of the encapsulated material was analyzed using atomic force microscopy (AFM), which showed encapsulated bead size around 250 nm with uniform distribution. The percentage entrapment of DEPA in the encapsulated samples was about (70 ± 5)%. A slow release study of DEPA from the encapsulated biopolymer (alginate) in isopropyl alcohol was also carried out, which showed continuous release up to five hours.

Keywords:

• calcium alginate
• DEPA
• encapsulation
• insect repellent
• microsphere

Acknowledgments

We would like to show our gratitude to the Director, DRDE, Gwalior, for providing financial support.