HPLC detection of marker compounds during buccal permeation enhancement studies

A simple, isocratic and sensitive high-performance liquid chromatographic (HPLC) method was developed and validated for the simultaneous analysis of marker compounds for the aqueous (atenolol) and lipoidal (lidocaine) pathways during permeation enhancement studies across the buccal mucosa. A reversed-phase C18 column with UV detection at 224 nm was used for chromatographic separation and analysis, respectively. The mobile phase contained a mixture of acetonitrile-methanol-monobasic potassium phosphate (pH 3.0; 50 mM) (7.5:7.5:85, v/v/v). The permeabilities of marker compounds were determined across porcine buccal mucosa, which was either untreated (control) or pre-treated with sodium glycodeoxycholate (GDC-Na; 10 mM). The calibration curve showed good linearity over the concentration range of 0.1-25 μg/mL. The intra- and inter-day accuracy and precision were also within acceptable limits. The application of this method was demonstrated by an increase in the permeation of atenolol after pre-treatment with GDC-Na while the permeation of lidocaine did not change significantly.