column, and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was applied for quantification. A simple protein precipitation method was used to pretreat the plasma; the extraction recovery (ER) was about 100%, and the matrix effect (ME) could be negligible. The method was linear over the concentration ranges of 0.625-2500.00 ng/mL for propranolol. The precision and accuracy were within acceptable limits. The lowest limit of quantification (LLOQ) was 0.625 ng/mL. This simple method was validated and successfully applied to support the pharmacokinetic study after administration of the propranolol transdermal drug delivery system to Sprague-Dawley rats.
Li et al. (2026) studied this question.