Release Characteristics of an Essential Oil Component Encapsulated with Cyclodextrin Shell Matrices

Area of Science:

• Pharmaceutical Science
• Materials Science
• Physical Chemistry

Background:

• Essential oils, like myrcene, exhibit poor aqueous solubility and high volatility.
• Cyclodextrins (CDs) are employed to encapsulate essential oils, enhancing their stability and functional properties for pharmaceutical and food applications.
• Understanding the release kinetics of encapsulated compounds is crucial but limited in existing studies.

Purpose of the Study:

• To characterize the physico-chemical properties and release behavior of myrcene encapsulated in four different cyclodextrins: α-CD, β-CD, γ-CD, and HP-β-CD.
• To determine the release mechanism of myrcene from these inclusion complexes (ICs).

Main Methods:

• Inclusion complexes (ICs) of myrcene and four CDs were prepared using freeze-drying.
• Physico-chemical properties were analyzed using particle size analysis, SEM, FT-IR, and DSC.
• Release behaviors at varying temperatures were modeled using kinetic models (Avrami, Page, etc.), and binding modes were identified via molecular modeling.

Main Results:

• CDs effectively encapsulated myrcene, with release kinetics well-simulated by Avrami and Page models.
• Release rates showed an initial unsteady state followed by stabilization after 20 hours; most ICs followed diffusion-controlled release, except γ-CD/myrcene.
• Alpha- and beta-cyclodextrins (α-CD and β-CD) demonstrated preferable stability and release characteristics for myrcene encapsulation.

Conclusions:

• The choice of cyclodextrin significantly impacts myrcene encapsulation and stability.
• Kinetics parameters and molecular modeling effectively explain binding behavior and release profiles.
• This research provides a basis for selecting suitable cyclodextrin matrices for essential oil encapsulation.