HPLC Analysis of Children’s Dimetapp Cold and Cough Formulation on Coresep 100 Mixed-Mode Column

Application description

Dimetapp Cold & Cough for kids is a liquid medicine containing three active ingredients: a nasal decongestant (Phenylephrine HCI), an antihistamine (Brompheniramine maleate) and a cough suppressant (Dextromethorphan HBr). There are multiple excipients in the formulation for the flavor, thickness, and preservation. The nasal decongestant works to temporarily restore free breathing through the nose to help clear a stuffy nose. The antihistamine/cough suppressant in this liquid cough medicine is tough on common upper respiratory symptoms like runny nose, sneezing, itchy, watery eyes, and itching of the nose or throat, as well as coughing due to minor throat irritation. Phenylephrine is a hydrophilic basic compound with poor retention in reversed-phase chromatography. Brompheniramine is a hydrophobic basic compound with strong retention and poor peak shape on traditional reversed-phase columns. Dextromethorphan is a hydrophobic basic compound with strong retention and poor peak shape when reversed-phase columns are used. We have developed a simple but robust method for analysis of active ingredients and excipients of Dimetapp formulation. All active compounds and excipients are retained and separated by several mechanisms - reversed-phase, cation-exchange, and anion-exclusion. Inactive ingredients in the formulation include Anhydrous Citric Acid, Artificial Flavor, Fd&C Blue No. 1, Fd&C Red No. 40, Glycerin, Propylene Glycol, Purified Water, Sodium Benzoate, Sodium Citrate, Sorbitol Solution, Sucralose. The retention of compounds is adjusted by changing the amount of ACN, buffer pH, and buffer concentration. The method can be applied to the analysis of drugs in biofluids. Most common detection techniques can be used (UV, ELSD, mass-spec, etc.). Core-shell columns provide very high efficiency of separation and mixed-mode provides unique selectivity and ability to retain hydrophilic compounds without the use of ion-pairing reagents.

Conditions of Experiment
Column: Coresep 100
Separation Modes: reversed-phase, cation-exchange
Column Dimenstions: 4.6x150 mm, 2.7 um, 90A
Mobile Phase: "A: 10% ACN with 0.02% H2SO4
B: 70% ACN with 0.2% H2SO4
from 100% A to 100% B in 8 min, 4 min hold "
Detection: UV 275
Sample: various
Injection: 3 uL
Flow rate: 1 ml/min
Class of compounds: Amines, Aromatic base, Catecholamine, Drug, Neurotransmitter
Nature of compounds: Basic, Hydrophilic, Hydrophobic, Polar
Compounds: Phenylephrine, Dextromethorphan, Brompheniramine