Assessing the physicochemical properties of freeze- dried microencapsulated Xylopia aethiopica herbal fruit extract

Abstract

Advances in material science have improved processability and release of bioactive plant extracts. Xylopia aethiopica plant extract was microencapsulated with gum-arabic wall-material, and freeze- dried. The drug-material interaction was evaluated using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX). The micromeritics and dissolution properties of the crude and microencapsulated extracts were determined. The FTIR analysis showed similarities in the spectra of the extracts, and additional peaks for the microencapsulated extract that were not detected in the crude extract. The SEM result for crude extract revealed two distinct, irregularly shaped and ≈10 μm- sized particles, whereas the microencapsulated form revealed numerous minute, warped, threadlike and ≈15 μm sized particles. The EDX result of the microencapsulated form showed more diverse range of elements. These microencapsulated drug-material interaction results infer non-complex structural, morphological and compositional changes to the crude extract. The angle of repose, Carrs’ index and Hausner ratio for microencapsulated extract were 28.61°, 11.50 % and 1.13 respectively, compared to 32.00°, 12.35 % and 1.14 respectively for the crude form. These micromeritics results indicate improved flow properties for microencapsulated extract. Dissolution test showed improvement in the dissolution of the microencapsulated form, with its absorbance peaking at 0.079 at 45 minutes, compared to 0.021 absorbance for the crude extract. This study suggests that microencapsulation and freeze- drying enhanced processability and release of Xylopia aethiopica extract. There is a need to conduct biological assay to explore the therapeutic potentials of this microencapsulated extract.