Objective: This study aims to establish an efficient, sensitive and specific analytical method
(in vitro and in vivo) for syringic acid.
Method: Syringic acid loaded liposome was prepared and characterized. In vitro and in vivo chromatographic
conditions for the determination of syringic acid were investigated, with the application verified
by pharmacokinetics and biodistribution studies.
Results: The developed liposomal formulation produced homogeneous regular, spherical and multilamellar-
shaped liposome. Efficient HPLC method for the analysis of syringic acid was established and
validated. The chromatographic separation was performed on a Waters symmetry C18 column (4.6 × 150
mm, 5 µm) at 25 °C by using mobile phases of 30 % methanol and 70 % acetic acid solution (0.1 %) (in
vitro) and 28 % methanol and 72 % acetic acid solution (0.1 %) (in vivo) at a flow rate of 0.8 mL/min.
The wavelength was set at 272 nm. Vanillin was used as internal standard for the in vivo analysis. The
established linearity ranges of SA were 1 - 100 µg/mL (R2 = 0.9997) in vitro and 0.125 – 64 µg/mL (R2
= 0.9991) in vivo. In vitro accuracy of the method was > 99%, and in vivo accuracies were between
91.23 % - 109.54 %, while the precisions met the acceptance criterion. In vivo HPLC method was also
confirmed by pharmacokinetics and biodistribution studies.
Conclusion: Established HPLC method exhibited high linearity, precision, accuracy and specificity,
could be used for quantitative determination of SA in vitro and in vivo.