The most popular and convenient route of drug administration remains the oral route,
however, protein and peptide drugs such as insulin have poor membrane permeability and
stability in the gastrointestinal tract. Absorption enhancers can be added to drug delivery
systems to overcome the epithelial cell membrane permeability problem. Although previous
studies have shown that aloe leaf materials improve the transport of drugs across intestinal
epithelia, their performance in solid oral dosage forms has not yet been investigated.
Beads containing insulin and each of the selected absorption enhancers (i.e. Aloe ferox,
Aloe marlothii and Aloe vera gel materials) were produced by extrusion-spheronisation,
using a full factorial design to optimise the formulations based on transepithelial electrical
resistance (TEER) reduction of Caco-2 cell monolayers as response. The optimum bead
formulations were evaluated in terms of friability, mass variation, particle surface texture,
shape, size and dissolution. The transport of insulin across excised pig intestinal tissue from
the optimised bead formulations was determined over a 2 h period. The samples obtained
from the transport studies were analysed for insulin content by means of high-performance
liquid chromatography (HPLC).
The results showed that the TEER reduction, as an indication of tight junction modulation,
obtained for the bead formulations containing aloe materials was concentration dependent.
Furthermore, inclusion of croscarmellose sodium (Ac-di-sol®) as a disintegrant showed an
enhanced TEER reduction effect in combination with the aloe gel materials. Dissolution
profiles indicated that the beads containing aloe leaf materials in conjunction with insulin,
released the insulin within an hour. In accordance with the TEER reduction results, the
A. marlothii and A. vera materials containing beads showed similar increased insulin delivery
across excised pig intestinal tissue, which was pronouncedly higher than that of the control
group (insulin alone).
It can be concluded that beads containing aloe leaf materials have high potential as effective
delivery systems for protein therapeutics such as insulin via the oral route of administration. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:nwu/oai:dspace.nwu.ac.za:10394/15335 |
| Date | January 2014 |
| Creators | Kleynhans, Elmarie |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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