Analytical Method Validation of Vilazodone with Spectrofluorimetric Detection in Rabbit Plasma

Irene Sartini,Mario Giorgi,Beata Łebkowska-Wieruszewska,Marco Salvadori,Amnart Poapolathep

doi:10.3844/ajavsp.2019.50.56

Abstract

Vilazodone (VLZ) is an antidepressant agent approved in 2011 by Food and Drug Administration (FDA) for the treatment of major depressive syndromes. Its chemical structure derives from trazodone which is used as an off-label drug for dogs and cats in order to induce sedation and reduce anxiety, behavioural and pre-and post-operative stress. VLZ could be a potentially useful compound in reducing severe anxiety responses in pet animals. The aim of the present research was to develop and validate a method to quantify VLZ in rabbit plasma. A 500 μL aliquot of rabbit control plasma was added to 50 µL of IS (0.1 ug/mL) and 100 µL of NaOH 0.1M. Then 1 mL of Et2O:EtOAc (70:30 v/v) was added and the sample, shaken and centrifuged. The organic layer was transferred into a clean polypropylene vial. This procedure was repeated twice. The combined supernatants were evaporated under nitrogen at 40°C and reconstituted with 100 µL of mobile phase. 50 µL of this latter solution was injected onto HPLC-FL. The mobile phase consisted of Na2HPO4 (0.02M, pH 5):ACN (67:33 v/v) at a flow rate of 1 mL/min. The analytical column (C18) was maintained at 40°C. Excitation and emission wavelengths were set at 353 and 486 nm, respectively. Times of retention of VLZ and IS were 3.26±0.09 and 4.70±0.08 minutes, respectively. The recovery of VLZ was about 83%. Limits of quantification and detection were 0.005 µg/mL and 0.001 µg/mL, respectively. This method was verified by determining VLZ concentration in rabbit plasma after a 1 mg/kg single IV administration. The analysis of samples allowed the calculation of the main pharmacokinetic parameters. In conclusion, the present research was able to quantify VLZ in rabbit plasma after VLZ administration. This method might have application for pharmacokinetic or toxicological studies.

Highlights

In veterinary medicine, SSRIs such as fluoxetine and fluvoxamine are frequently used to control aggression, obsessive-compulsive disorder and separation anxiety in pets (Sargisson, 2014; Overall, 1997)
Phenylpiperazine compounds such as trazodone are used as off-label drugs in pet animals, in order to reduce anxiety, behavioural stress, sedation and pre- and post-operation stress (Chea and Giorgi, 2017)
The method was developed by combining data from early reports with some modifications (Studies et al, 2012)

Summary

Introduction

SSRIs such as fluoxetine and fluvoxamine are frequently used to control aggression, obsessive-compulsive disorder and separation anxiety in pets (Sargisson, 2014; Overall, 1997). Phenylpiperazine compounds such as trazodone are used as off-label drugs in pet animals, in order to reduce anxiety, behavioural stress, sedation and pre- and post-operation stress (Chea and Giorgi, 2017). It has a similar chemical structure to trazodone (Fig. 1), shares the same mechanism of action, but has been reported to be more active and to possess a better safety profile. Thanks to the favourable PK/PD features shown in humans, this compound appears to be a likely option in pets for anxiety disorders such as travel, separation, noise phobia, veterinary visits and hospitalization

Objectives

Methods

Results