A simple and sensitive HPLC-UV method for the quantification of piceatannol analog trans-3,5,3′,4′-tetramethoxystilbene in rat plasma and its application for a pre-clinical pharmacokinetic study

A simple and sensitive HPLC-UV method was developed and validated for the quantification of piceatannol analog trans-3,5,3′,4′-tetramethoxystilbene (M-PIC) in rat plasma. Following protein precipitation with three volumes of acetonitrile, the analytes were separated on a RP-HPLC column, which was protected by a guard column through gradient delivery of a mixture of acetonitrile–water at 40 °C. The UV absorbance at 325 nm was recorded to quantify M-PIC. The retention time of M-PIC and trans-3,5-dimethoxystilbene (internal standard) was 7.4 and 8.4 min, respectively. The calibration curves were linear (R2 > 0.9989) with a lower limit of quantification of 15 ng/ml. The intra- and inter-day precisions, in terms of RSD, were all lower than 7.5%. The average analytical recovery ranged from 97.0 to 104.3% while the average absolute recovery ranged from 101.8 to 105.0%. This reliable HPLC method was subsequently applied to assess the pharmacokinetic profile of M-PIC in Sprague–Dawley rats using 2-hydroxypropyl-β-cyclodextrin as a dosing vehicle. The terminal elimination half-life (t1/2λz) and clearance (Cl) of M-PIC were 313 ± 20 min and 33.1 ± 3.9 ml/min/kg, respectively; and its absolute oral bioavailability was as high as 50.7 ± 15.0%. M-PIC appeared to have a favorable pharmacokinetic profile and further pharmacological investigation on this phyto-stilbene was warranted.