Skin delivery of selected hydrophilic drugs used in the treatment of skin diseases associated with HIV/AIDS by using elastic liposomes
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.
- ETD@PUK