Acne is a multifactorial skin disease affecting about 80 % of people aged 11 to 30. Several
systemic and topical treatments are used to treat existing lesions, prevent scarring and
suppress the development of new lesions. Topical therapy is often used as first line treatment
for acne, due to the location of the target organ, the pilosebaceous unit, in the skin. Retinoids
are widely used as oral or topical treatment for this disease, with tretinoin and adapalene being
two of the most used topical retinoids.
The transdermal route offers several challenges to drug delivery, e.g. the excellent resistance of
the stratum corneum to diffusion, as well as variable skin properties such as site, age, race and
disease. Some additional difficulties are associated with the dermatological delivery of tretinoin
and adapalene, which include suboptimal water solubility of the retinoids, isomerisation of
tretinoin in the skin, mild to severe skin irritation, as well as oxidation and photo–isomerisation of
tretinoin, even before crossing the stratum corneum.
Researchers constantly strive to improve dermatological retinoid formulations in order to combat
low dermal flux, skin irritation and instability. The release kinetics of tretinoin varies greatly
according to the way in which it is incorporated into the formulation and according to the type of
formulation used. Little research has been conducted regarding improved formulations for
adapalene.
Pheroid technology is a patented delivery system employed in this study in order to improve
the dermal delivery of retinoids. Tretinoin and adapalene were separately incorporated into
castor oil, vitamin F and Pheroid creams. The creams were evaluated in terms of their in vitro
retinoid release, in vitro transdermal diffusion and stability.
Castor oil and Pheroid creams were superior in terms of release and dermal delivery of
adapalene. Tretinoin was best released and delivered to the dermis by castor oil cream. The
castor oil creams were the most stable formulations, whereas the Pheroid creams were the
most unstable. In terms of release, dermal diffusion and stability, castor oil cream proved to be
the most suitable cream for both tretinoin and adapalene. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2011.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:nwu/oai:dspace.nwu.ac.za:10394/4866 |
| Date | January 2010 |
| Creators | Krüger, Arina |
| Publisher | North-West University |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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