Analysis of Trazodone by Lucidity LC-UV

Trazodone is a drug compound that was initially designed to treat depression and anxiety disorders but has also become widely used as a sleep aid.  Because of its increasing popularity, we thought we would test it in our Lucidity LC-UV.  It’s typically found in pill form in 25mg to 100mg pills.

We got our hands on some 100mg Trazodone tablets and ordered a Trazodone standard from Cerilliant (T-030-1ML).  We then started with a very simple sample preparation involving Methanol, which worked well.  We chose this preparation using Methanol because the standard came in a Methanol solution and the sample seemed to solubilize well using this Methanol preparation.  No more optimization was given to the sample prep than that.

Standard Preparation:

The standard we ordered is a 1mg/mL solution.  We pipetted 100uL of this stock solution into 900uL of Methanol and mixed it well to create a final standard concentration of 0.1 mg/mL.

Sample Preparation:

We placed 100mg Trazodone tablet into a 100mL volumetric flask and added Methanol to 50mL.  We then sonicated for 10 minutes while swirling periodically.  This served as our stock solution.  We then created a sample for the Lucidity LC-UV by pipetting 100uL of this stock solution into 900uL of Methanol, creating a sample concentration of around 0.1mg/mL of Trazodone in Methanol.

We used the following HPLC method, which was chosen because that’s the method that was used to QC to the standard.  The only adjustment we made was to the column.  We used a standard column that we had available versus the C18, 50mm x 3.0mm, 2.7um column used by the vendor.  This shifted the retention time of the peak, but the method worked well, and produced one nice, clean peak just like the QC report.

The first image shows one of the standard runs showing a single peak for Trazodone.

Trazodone standard

The second image shows one of the sample runs showing a single peak.

Trazadone sample

Overlaying these runs gives us good confidence that the peak from the sample run is in fact Trazodone.

Overlay of the Trazodone standard and sample

This last image shows how the report that can be generated from the Lucidity LC-UV when running a batch of samples and standards.  In this particular study, we only ran one concentration of the standard and only ran one sample.  We ran 3 runs of the standard first to establish repeatability, then ran 2 runs of the sample, then ran a bracket standard after the sample runs.  The data for these runs is contained in the report shown in the image below, which also calculates concentration and percent recovery of the compound of interest (Trazodone in this case) based on the concentration and area counts of the standard versus the area counts and dilution of the samples.  This information can all be included in the method and batch used to run a certain sample so that the output from the system is in usable and convenient units for the user and limits calculation errors by analysts.  In this case the sample data is presented in concentration and % recovery, which are in many cases the units of interest to an analyst.

Lucidity LC-UV sample report

Ideally, we would run multiple sample concentrations of the standard to make a multi point calibration curve, which would likely give us a more accurate estimate of the concentration of Trazodone in the samples.

So, sleep well, there are reliable and simple ways to test the amount of Trazadone in your sleeping pills!