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Hydrocodone/Acetaminophen
Simple, Robust Assay Method
Click here to view
printable Application Sheet
Notes:
Hydrocodone is a semi-synthetic opioid used as a narcotic analgesic to relieve moderate to severe pain. The formulation which includes
acetaminophen is marketed under several trade names, including Vicodin® and Lortab®.
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Method Conditions
| Column |
Cogent Phenyl Hydride™, 4µm, 100A |
| Catalog No. |
69020-7.5P |
| Dimensions |
4.6 x 75 mm |
| Mobile Phase |
A: DI H2O/ 0.1% TFA
B: Acetonitrile/ 0.1% TFA |
| Gradient |
| time (min.) |
%B |
| 0 |
5 |
| 1 |
5 |
| 5 |
60 |
| 6 |
5 |
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| Temperature |
35° C |
| Flow rate |
1.0 mL/min |
| Injection Volume |
5 µL |
| Samples |
One tablet containing 5 mg hydrocodone/ 500 mg acetaminophen was ground and diluted to 100 mL with 50/50 solvent A/solvent B
mixture. The solution was then sonicated 10 min and filtered with a 0.45 µm nylon syringe filter (MicroSolv Tech
Corp). |
| Peaks |
1. Acetaminophen
2. Hydrocodone |
| Detection |
0-4 min: UV 295 nm;
4-10 min: UV 210 nm |
| t0 |
0.9 min |
Discussion
Hydrocodone can yield poor peak shapes in many conventional reverse-phase C18 methods due to its tertiary amine group. The USP assay method for
hydrocodone in combination with acetaminophen uses triethylamine as a mobile phase additive to improve the peak shape. In this method however,
only trifluoroacetic acid is needed in the mobile phase for a symmetrical hydrocodone peak when the Phenyl Hydride™ column is used. In
addition, the repeatability of the analysis is excellent as the five-run overlay in the figure shows. Retention time %RSDs of < 0.1% were obtained
for both peaks.
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