Determination of active ingrediients in cold cough syrups by HPLC

DETERMINATION OF ACTIVE INGREDIENTS IN COLD COUGH SYRUPS BY HPLCCough and cold pharmaceutical preparations are one of the most extended formulations in the world. These preparations represent complex formulations containing several active ingredients and a broad spectrum of excipients such as flavoring agents, saccharose, acidulants, natural or artificial coloring and flavoring agents, dyes, sweeteners and preservatives. The majority of these ingredients are present as a mixture of basic nitrogenous amino compounds and their separation in pharmaceutical forms is quite complicated due to similarities of their physical and chemical properties.A new simple and sensitive liquid chromatographic method has been developed and validated for the simultaneous determination of pseudoephdrine HCI , pheniramine maleate, acetaminophen, guaifenisin, pyrilamine maleate, chlorpheniramine maleate, triprolidine HCI, dextromethorphan HBr, diphenhydramine HCI in cough and cold pharmaceuticals. The separation of these compounds was achieved within 37.9 min on a Nucleodur gravity C18 column using an isocratic elution. The mobile phase was a mixture of 38% methanol, 62% of 80 mM KH2PO4 aqueous solution adjusted to pH 3.0, to which was added 10% (v/v) orthophosphoric acid. The chromatographic separation of these compounds performed at room temperature, with flow rate of 0.75 mL/min. The internal standard was 2,4,6-trimethoxybenzaldehyde. An ultraviolet absorption at 210 nm was monitored.The selectivity, linearity of calibration, accuracy, intraday and interday precision, recovery and forced degradation studies were examined as parts of the method validation. The proposed liquid chromatographic method was successfully applied for the routine analysis of these compounds in different cough and cold pharmaceutical preparations such as syrups and tablets.Key words: Reversed-phase liquid chromatography, simultaneous determination, cough syrup, validation, cold formulations, forced degradation