No abstract

Alpha-tocopherol or TOC is among substances that has medicinal capabilities. However, alpha-tocopherol is vulnerable to surrounding milieu settings. This leads to the necessity to shield it against unforeseen alterations during the storing or handling procedures. Encapsulation is presented as a procedure which can shield active agents from adverse changes by means of coating with polymers. In this study, gum Arabic (GA), a biopolymer derived from Acacia species, was used as the encapsulation matrix. Encapsulation process was done at different concentrations of GA dispersions (10%, 20%, 30% and 40%) and at various pH levels (5.4, 6.4, 7.4 and 8.4). To evaluate the key conditions of TOC encapsulation in GA dispersion we analysed TOC encapsulation efficiency (EE) and rate of release (RR) from GA dispersions as well as loading capacity (LC) of GA for TOC. The EE, RR and LC were determined by measuring the TOC concentration in the GA dispersions using UV Visible spectrophotometry at 291 nm. Results disclosed that the key conditions for achieving a high LC by GA with high efficiency of TOC encapsulation were in a dispersion of 20% GA at pH range of 6.4 and 7.4. The best EE of TOC and LC of GA were 48% and 2.8%, respectively, with a TOC average RR of 1.05-1.09 ppm/day. The results indicate that gum Arabic is a potential matrix to encapsulate alpha-tocopherol.

This paper investigates the interaction within a liposome-based drug delivery system in silico. Results confirmed that phospholipids, cholesterol, beta-carotene, and vitamin C in the liposome structures interact noncovalently. The formation of noncovalent interactions indicates that the liposomal structures from phospholipid molecules will not result in chemical changes to the drug or any molecules encapsulated within. Noncovalent interactions formed include (i) moderate-strength hydrogen bonds with interaction energies ranging from −73.6434 kJ·mol−1 to −45.6734 kJ·mol−1 and bond lengths ranging from 1.731 Å to 1.827 Å and (ii) van der Waals interactions (induced dipole-induced dipole and induced dipole-dipole interactions) with interaction energies ranging from −4.4735 kJ·mol−1 to −1.5840 kJ·mol−1 and bond lengths ranging from 3.192 Å to 3.742 Å. The studies for several phospholipids with short hydrocarbon chains show that changes in chain length have almost no effect on interaction energy, bond length, and partial atomic charge.