A Simple, Linear Gradient for a Challenging Drug Product

This Gradient Method will produce a good separation of Benzonatate from excipients and degradants in a USP Capsule Formulation. Benzonatate contains a secondary amine group, which can cause peak tailing.


Method Conditions
Column: Cogent Bidentate C18™, 4μm, 100Å
Catalog No.: 40018-75P
Dimensions: 4.6 x 75mm
Mobile Phase:
A: DI Water / 10mM Sodium Phosphate Monobasic
B: 80% Acetonitrile / 20% DI Water / 10mM Sodium Phosphate Monobasic

Time (minutes)  %B
0 0
15 100

Temperature: 40°C
Injection vol.: 10μL
Flow rate: 1.5mL / minute
Detection: UV @ 280nm

Notes: Benzonatate is a non-narcotic oral antitussive (cough suppressant) drug, taken orally, which works by anesthetizing the tissues of the lungs and pleura responsible for the cough reflex. It is sold under the brand name Tessalon Perles (gelcaps) or Tessalon Capsules.


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