Simultaneous determination the concentration change of ketoconazole and dexamethasone acetate: application to drug-drug interaction in human keratinocyte

Abstract

BackgroundThe combination of ketoconazole and dexamethasone acetate is one of the commonly used treatments in dermatology regiment for skin inflammation accompanied by fungal infections. This interaction of ketoconazole and dexamethasone may make the drug much effective, decrease the adverse reaction or toxic effects. At present, there was no information about the interaction of these two external drugs. Therefore, it was necessary to build a model to measure the levels and evaluate the interaction of ketoconazole and dexamethasone acetate in skin cells. MethodsIn our study, the determination methodology of ketoconazole and dexamethasone acetate in human keratinocyte (HaCaT cells) was established and the interaction of these two drugs in cells was explored. HaCaT cells were cultured in medium containing ketoconazole, then they were sequentially cultured with or without dexamethasone acetate treatment for another 1, 2, 4, 8 and 12 h. The samples were then harvested and the concentrations were quantified by enhanced BCA (the bicinchoninic acid) protein assay. Furthermore, the analytes in the cell suspension were also prepared and analyzed by LC-MS method. ResultsAs a result, ketoconazole and dexamethasone acetate were detected at the concentration range of 0.02 to 5 μg/mL and 0.2 to 100 μg/mL, respectively. The RSD (relative standard deviation) and RE (relative error) of precision and accuracy of the two analytes in the cell suspension were all less than 15 %. The matrix effect values variations were all less than 15%. The results showed that there was no significant difference in the concentration of ketoconazole with or without dexamethasone acetate treatment within 12 h. ConclusionsA simple, sensitive and rapid LC-MS method which could quantify these two analytes in cells simultaneously was developed for the first time. The results of the concentration changes meant that no interaction occurred when dexamethasone sequentially administrated for 12 h after ketoconazole treatment. This method was successfully applied to establish the cell pharmacokinetics methodology and preliminary studied the metabolism of drug-drug interaction of ketoconazole and dexamethasone acetate.