| Summary: | Due to the immuncompromised status of AIDS patients, secondary infections and
malignancies are common. Conditions secondary to AIDS for which patients require
treatment include Karposi's sarcoma (treated with methotrexate), varicella-zoster (treated
with antivirals such as acyclovir) and herpes simplex (also treated with antivirals like
acyclovir or idoxuridme). However the clinical efficacy of these drugs is limited by poor
skin permeability.
Few reports, however, have dealt with the delivery of low molecular weight hydrophilic
drugs from these vesicles (El Maghraby et al, 2000). The aim of our study was to
investigate in vitro permeation of methotrexate, acyclovir and idoxuridine across human
epidermal membrane from elastic liposomes. The intent was to establish whether
formulation of these hydrophilic drugs into elastic liposomes would enhance their skin
permeation parameters.
We developed and validated high-performance liquid chromatographic techniques for
quantitative analysis of methotrexate, idoxuridine and acyclovir. Elastic liposomes were
prepared from various phospholipids- phosphatidylcholine 78.6%; phosphatidylcholine
50%; hydrogenated phosphatidylcholine 90%; phosphatidylcholine 95% and surfactants -
sodium cholate, sodium deoxycholate, Span 20, 40, 60, 80. These vesicles were
characterised by transmission electron microscopy. The solubilities of methotrexate,
acyclovir and idoxuridine were determined. Phospholipon G (95% phosphatidylcholine)
was chosen for the preparation of the liposomes with different surfactants. Permeation of
methotrexate, acyclovir and idoxuridme from these vesicles across human epidermal
membrane was investigated.
Flux values for methotrexate, acyclovir and idoxuridine values (J) obtained by curve-fitting
of data using Easyplot were compared to those obtained by linear regression. We
used Student's t-test to determine statistically significant differences in the flux values of
the formulations. A computer program http://www.physics.csbsju.edu/stats/ttest-
bulk-form.html was used for this purpose. Our results indicate that there are no
statistically significant differences between flux values from elastic liposomes and
saturated aqueous solutions. === Thesis (Ph.D. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2004.
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