Pyrilamine

HPLC Analysis of Cough and Cold Medications Active Ingredients and Acidic Counterions on Heritage MA Mixed-Mode Column
Application description

There are several groups of compounds which are used as active and inactive ingredients in various over-the-counter drug compositions. These compounds are different in nature and can be organic and inorganic. Most of the active ingredients are either hydrophobic basic, hydrophilic basic or hydrophilic neutral compounds. Basic active ingredients of cough and cold remedies used as salts of organic and inorganic acids. The most commonly used hydrophobic active ingredients are doxylamine, pyrilamine, chlorpheniramine, brompheniramine, and dextromethorphan. Doxylamine is an antihistamine drug, used to relieve symptoms of allergy, hay fever, and the common cold. Doxylamine is used in combination with other active ingredients to provide effective nighttime relief from cough and cold symptoms. Pyrilamine is an antihistamine drug, which targetsH1 receptors as an inverse agonist. Brompheniramine is an antihistamine drug of propylamine nature. Chlorpheniramine is an antihistamine used to treat symptoms such as allergic rhinitis. Dextromethorphan is a medication mostly used as a cough suppressant. It is a morphine type of medication with sedative, dissociative, and stimulant properties. Succinic acid is a hydrophilic diacid that is used as a counterion. Maleic acid is hydrophilic diacid which is used as a counterion. Both compounds have very limited retention even in RP-AQ columns. Due to the strongly hydrophobic and basic properties of these compounds, they demonstrate a poor peak shape in traditional reversed-phase chromatography due to the overloading of residual silanol groups on the surface when these basic drugs are analyzed. In addition to this, hydrophilic counterions are not retained in RP because there is no mechanism of retention for these acidic hydrophilic compounds. Both problems were eliminated by using Heritage MA reversed-phase anion-exchange column. Column and method demonstrate high efficiency and good peak shape for acidic and basic analytes. It can be used to develop methods for various cough, cold, and congestion compositions without the use of ion-pairing reagents. Compounds are well retained by a combination of one or more mechanisms. The column is compatible with 100% ACN and 100% water as well as with most buffers with pH 1.5-7. Various additives to the mobile phase can be used based on the nature of samples and detection techniques.

Conditions of Experiment
Column: Heritage MA
Separation Modes: reversed-phase, cation-exclusion, anion-exchange
Column Dimenstions: 4.6x150 mm, 3 um, 100A
Mobile Phase: 5% ACN with 30 mM AmFm pH 3
Detection: UV 275
Sample: various
Injection: 3 uL
Flow rate: 1 ml/min
Analytes
Class of compounds: Amines, Aromatic base, Drug, Organic acid, Pyridine
Nature of compounds: Acidic, Basic, Hydrophilic, Hydrophobic, Polar
Compounds: Doxylamine, Pyrilamine, Succinic acid, Chlorpheniramine, Brompheniramine, Maleic acid, Dextromethorphan
HPLC Analysis of Midol Analgesic Formulation on Heritage MA Mixed-Mode Column
Application description

Midol is an over-the-counter (OTC) formulation used for menstrual cramping and other effects related to menstruation. It can also be used as a pain medication for other purposes. The active ingredients include acetaminophen, caffeine and pyrilamine. Acetaminophen (or paracetamol) is a relatively hydrophilic drug which is used to treat pain and fever. Caffeine is a relatively hydrophobic and neutral central nervous system (CNS) drug stimulant. It is considered a psychoactive drug. Pyrilamine or merylamine is a first-generation antihistamine medication. It is hydrophobic and basic in nature. The Midol formulation was analyzed on Heritage MA mixed-mode reversed-phase-, cation-exchange, anion-exclusion column. It retains caffeine and acetaminophen by the pure reversed-phase mechanism. Pyrilamine is retained by a combination of reversed-phase and cation-exclusion mechanisms. Pyrilamine, due to its basic nature, shows poor peak shape when traditional reversed-phase columns are used. This poor peak shape is attributed to the interaction of basic groups in pyrilamine with residual silanols on the surface of reversed-phase columns. This problem does not exist in mixed-mode chromatography where residual silanols are shielded from interacting with basic analytes by the presence of strongly basic groups on the surface. The retention time of caffeine and acetaminophen is controlled by the amount of ACN. Pyrilamine retention is controlled by the amount of acetonitrile, buffer concentration, and buffer pH. The method is robust and reproducible and can be used for the analysis of neutral, acidic, and basic compounds. Buffer choice depends on the detection technique and the desired pH of the mobile phase. Heritage MA column is compatible with 100% water and 100% ACN and can be used either in a single mode or in multiple modes, depending on the nature of analyte and buffer and mobile phase composition.

Conditions of Experiment
Column: Heritage MA
Separation Modes: reversed-phase, cation-exclusion, anion-exchange
Column Dimenstions: 4.6x150 mm, 3 um, 100A
Mobile Phase: 5% ACN with 30 mM AmFm pH 3
Detection: UV 275
Sample: various
Injection: 3 uL
Flow rate: 1 ml/min
Analytes
Class of compounds: Aromatic base, Aromatic compound, Drug, Pyridine
Nature of compounds: Basic, Hydrophilic, Hydrophobic, Neutral
Compounds: Pyrilamine, Acetaminophen