Amoxicillin Analyzed Orthogonally with HPLC - AppNote
May 16, 2012
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Date: 16-MAY-2012 Last Updated: 31-AUGUST-2026
Orthogonal Analysis to USP Assay Method for Validation
The USP Assay Method for the antibiotic Amoxicillin is performed in Reversed Phase. Analysis by an Orthogonal Retention mode is very useful and can be readily done by HILIC mode of HPLC, using solvents common to both.A benefit of this Method is the more Symmetrical Peak Shape obtained. This is important for compounds such as Amoxicillin that can give poor Peak Shapes in many Reversed Phase Methods including the USP Monograph.
Peak: Amoxicillin
Method ConditionsColumn: Cogent Diamond Hydride™, 4 μm, 100Å
Catalog No.: 70000-7.5P
Dimensions: 4.6 x 75 mm
Mobile Phase:
-- A: DI Water / 10 mM Ammonium Acetate
-- B: 90% Acetonitrile / 10% DI Water / 10 mM Ammonium Acetate
Gradient:
| Time (minutes) | %B |
| 0 | 100 |
| 4 | 90 |
| 5 | 100 |
Flow rate: 1.0 mL / minute
Detection: UV @ 230 nm
Sample Preparation:
-- Stock Solution: 1 mg / mL Amoxicillin Trihydrate USP RS in 50:50 Solvent A / Solvent B diluent.
-- Working Solution: A 100 μL aliquot of the Stock Solution was diluted to 0.1 mg / mL using 900 μL 50:50 Solvent A / Solvent B diluent.
t 0 : 0.95 minutes
Note: Amoxicillin is a beta-lactam antibiotic used to treat a variety of bacterial infections. Its mechanism of action is by inhibition of the synthesis of bacterial cell walls.
