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Preparation, stability and in vitro evaluation of liposomes containing chloroquine / Stephnie Nieuwoudt

Malaria is currently a huge treat worldwide, as far as infections are concerned, and is
responsible for thousands of deaths per annum. The dilemma associated with the development
of anti–malarial drug resistance over the past few decades should be addressed as a matter of
urgency. Novel drug delivery systems should be developed in order to employ new and existing
anti–malarial drugs in the treatment and management of malaria. The aim of these delivery
systems should include an improvement in the efficacy, specificity, acceptability and therapeutic
index of anti–malarial drugs.
Previous studies have suggested that liposomes have the ability to encapsulate, protect and to
promote the sustained release of anti–malarial drugs. Two liposome formulations, namely
liposomes and chloroquine entrapped in liposomes, were formulated during this thesis and
evaluated by conducting a stability study and an in vitro study with the main focus on cell
viability.
The stability study consisted of a series of stability tests regarding the stability of nine liposome
and nine chloroquine entrapped in liposome formulations over a period of twelve weeks. The in
vitro study included three assays such as a reactive oxygen species assay, a lipid peroxidation
assay and a hemolysis assay. The aims of these studies included the manufacturing of
liposomes, the incorporation of chloroquine into liposomes, the determination of the stability of
the formulations as well as the evaluation of the possible in vitro toxicity of liposomes.
Results obtained from these studies revealed that liposomes remained more stable over the
stability study period in comparison to chloroquine entrapped in liposomes. The entrapment of
chloroquine within liposomes was possible, although the initial entrapment efficiency (%) of
14.55 % was much too low. The production of reactive oxygen species occurred to a small
extent in the red blood cells and the infected red blood cells. Equal amounts of reactive oxygen
species (%) was observed within both the red blood cells and the infected red blood cells with a
maximum value of 23.27 % in the presence of the chloroquine entrapped in liposomes at
varying concentrations. Red blood cells experienced the highest degree of lipid peroxidation
(%) in the presence of chloroquine, at varying concentrations, entrapped in liposomes. The
maximum amount of lipid peroxidation (%) was 79.61 %. No significant degree of hemolysis
(%) was observed in the red blood cells neither in the presence of the liposomes nor in the
presence of the chloroquine entrapped in liposomes at varying concentrations.
It can be concluded that liposomes are a more stable formulation and have less toxic effects on
red blood cells and infected red blood cells in comparison to the chloroquine entrapped in liposome formulations. Future studies should investigate the possibility of a more stable and
less toxic chloroquine entrapped in liposome formulation. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2011.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:nwu/oai:dspace.nwu.ac.za:10394/4740
Date January 2010
CreatorsNieuwoudt, Stephnie
PublisherNorth-West University
Source SetsSouth African National ETD Portal
Detected LanguageEnglish
TypeThesis

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