The encapsulation of active ingredients in various delivery systems is increasing, as it helps reduce side effects and achieve a greater therapeutic effect. Liposomes and transferosomes are common for dermal application due to their biocompatible ingredients and a high level of acceptance by the skin.
As part of the diploma thesis, we determined the potential toxicity of liposomes and transferosomes with and without the active ingredient, betamethasone dipropionate, on the keratinocyte cell line (NCTC2544). Betamethasone diproponate belongs to the group of corticosteroids, used for treating skin diseases with overly expressed inflammation. The studied systems were formulated with non-toxic ingredients, acceptable for dermal application: bidistilled water, lecithin, betamethasone dipropionate and Tween 80. Before the biological evaluation, we also studied the systems physical and chemical stability. Cytotoxicity was determined in two ways, firstly with a metabolic activity assay, and secondly with an inverted light microscope. In addition, we studied the influence of individual ingredients (with the exception of bidistilled water) on cytotoxicity. Tween 80 had the greatest impact, which was expected, since it is a surfactant with a certain irritating potential (metabolic activity of the cells at a concentration of 0,5 mg/mL was merely 2 %). Furthermore, we exposed the keratinocytes to four different system concentrations between 0,05 mg/mL and 0,5 mg/mL with the aim of determining the optimal concentration for use on healthy as well as compromised (atopic) skin. A lower cell viability was noted for transferosomes in comparison to liposomes. The following incompatibility was also evident when examining the cells under an inverted light microscope, as most of the cells were detached after 24 hours of exposure and had an atypical shape without intercellular connections. Based on the results of the evaluation of each individual ingredient, the cytotoxic effect of transferosomes can be attributed to Tween 80. The cells also demonstrated lower viability in the presence of the active ingredient. In conclusion, the concentration of 0,5 mg/mL can be defined as subtoxic for liposomes, but not also transferosomes, for which the subtoxic concentration is 0,25 mg/mL.
Due to their biocompatibility, liposomes represent a far more promising delivery system for betamethasone dipropionate than transferosomes.
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