Gradient Separation of Acetaminophen, Caffeine, and Butalbital

In this Method, a simple Reversed Phase gradient is used to separate the three components of a Fioricet tablet. Figure A shows the five-run overlay obtained from the gradient. Figure B shows a “zoomed in view” so that the Butalbital Peak can be seen clearly.

1. Acetaminophen
2. Caffeine
3. Butalbital

Method Condtions
Column: Cogent Bidentate C18™, 4µm, 100Å
Catalog No.: 40018-15P
Dimensions: 4.6 x 150mm
Mobile Phase:
A: DI Water / 0.1% Formic Acid
B: 97% Acetonitrile / 3% DI Water / 0.1% Formic Acid

Time (minutes) %B
0 10
6 70
7 10

Temperature: 35˚C
Injection vol.: 10µL
Flow rate: 0.8mL / minute
Detection: UV @ 240nm
Sample Preparation:
Stock Solution: Fioricet tablet was ground, added to 10mL volumetric flask and diluted with 50:50 Solvent A / Solvent B mixture. The flask was vortexed 5 minutes and a portion of the solution was filtered with a 0.45µm Nylon Syringe Filter.
Working Solution: 10µL of the stock was diluted with 990µL of 50:50 Solvent A / Solvent B mixture.
t0: 2.2 minutes

Note: Fioricet/Esgic is a combination of Acetaminophen, Caffeine, and Butalbital. It is used to treat tension headaches, muscle contraction headaches, and migraines.


No 137 Fioricet Analyzed with HPLC pdf 0.9 Mb  Download File