BACKGROUND: The aim of this work was to investigate the feasibility of using tissue surrogate matrices and plasma for determining drug concentrations in tissues by LC-MS/MS. RESULTS: The similarity of tissues was evaluated using eight model compounds with different SlogP values. For plasma dilution, the overall matrix effects of tissue samples were found to approximate to those of pure plasma samples when plasma percentage was increased. When a ten-fold plasma dilution was applied, the differences between the instrumental responses of diluted tissue samples and pure plasma samples with the same spiked concentrations were within ±20%. The results of tissue bioanalysis using plasma dilution and plasma curve for in vivo studies were acceptable with an averaged deviation of ±20-25% compared with data using traditional tissue curves. CONCLUSION: Results demonstrate that tissue samples can be quantified using surrogate matrices. Plasma standard curves can be used for quantitation of both plasma and plasma-diluted tissue samples.
BACKGROUND: The aim of this work was to investigate the feasibility of using tissue surrogate matrices and plasma for determining drug concentrations in tissues by LC-MS/MS. RESULTS: The similarity of tissues was evaluated using eight model compounds with different SlogP values. For plasma dilution, the overall matrix effects of tissue samples were found to approximate to those of pure plasma samples when plasma percentage was increased. When a ten-fold plasma dilution was applied, the differences between the instrumental responses of diluted tissue samples and pure plasma samples with the same spiked concentrations were within ±20%. The results of tissue bioanalysis using plasma dilution and plasma curve for in vivo studies were acceptable with an averaged deviation of ±20-25% compared with data using traditional tissue curves. CONCLUSION: Results demonstrate that tissue samples can be quantified using surrogate matrices. Plasma standard curves can be used for quantitation of both plasma and plasma-diluted tissue samples.