Quantitative Determination of Some Single and Multiple Component Drugs by Gas-Liquid Chromatography

Simultaneous Stability-Indicating Determination of Phenylephrine Hydrochloride, Phenylpropanolamine Hydrochloride, and Guaifenesin in Dosage Forms by Reversed-Phase Paired-Ion High-Performance Liquid Chromatography

“…Simultaneous GLC determinations are typically successful in assaying for phenylpropanolamine hydrochloride and other amines (1)(2)(3)(4)(5)(6)(7)(8). Simultaneous GLC determinations are typically successful in assaying for phenylpropanolamine hydrochloride and other amines (1)(2)(3)(4)(5)(6)(7)(8).…”

Automated, Simultaneous Determination of Dextromethorphan Hydrobromide, Glyceryl Guaiacolate, and Phenylpropanolamine Hydrochloride in Cough Syrups

“…The inclusion of soluble drugs in insoluble matrixes is well known as a means of controlling drug release rates from solid dosage forms. Diffusional models describing drug release from such systems were thoroughly described by T. Higuchi (1) and w. Higuchi (2). Systems have been designed in which "channeling agents" are.…”

Role of thermal dissociation in the direct gas-liquid chromatographic determination of amine maleate salts

“…Despite their relative involatility, certain classes of amine salts (alkaloids and nitrogenous drugs) have been found to yield analytically useful peaks upon direct injection into gas-liquid chromatographic (GLC) systems (1)(2)(3)(4)(5)(6)(7)(8)(9) without prior conversion to their free bases or the use of alkali-modified forecolumns, analytical columns, or carrier gases. Based on the retention times of the peaks obtained by using such unmodified systems, it has been postulated that thermal dissociation of the salts in heated portions of the GLC system may be occurring to liberate the conjugate free bases, which then elute in the normal manner (1, 3-5,10).…”

“…If so, however, the fate of the acid part of the salts, even where the acid may be organic, has not been accounted for experimentally. Also, the quantitative reproducibility of the postulated thermal conversion has been questioned (11,12), although attempts to exploit the direct salt injection procedure for quantitative purposes have been reported (8,13).…”