Micro-scale method for theophylline in body fluids by reversed-phase, high-pressure liquid chromatography.

Abstract

We describe a micro-scale method for determining serum theophylline. The chromatography system includes a muBondapack C18 column and acetonitrile, 70 ml/liter of sodium acetate buffer (10 mmol/liter, ph 4.0) as the mobile phase. Test serum or plasma, 30 mul, is mixed with an equal quantity of a solution containing the internal standard, beta-hydroxyethyltheophylline in acetonitrile/sodium acetate buffer (20 mmol/liter, pH 4.0), 7/43 by vol. After the precipitate is removed by centrifugation, the mixture is chromatographed and the amount of theophylline calculated from the ratio between peak heights for theophylline and the internal standard. Advantages include easy sample preparation, involving only addition of internal standard and centrifugation before injection, long column life, and the suitability of the internal standard, which is adjusted to a peak height equivalent to 20 mg of theophylline per liter for easy computation of results.

Lack of Effect of Influenza Vaccine on Theophylline Levels and Warfarin Anticoagulation in the Elderly

“…Serum theophylline concentrations were deter-mined by the high-peiformance liquid chromatography (HPLC) assay of Orcutt et al 18 Aiialysis of variance (AN0VA)'O and Scheffe's multiple comparison tes tszo were peiformed to detect differences in theophylliiie concentrations, and prothrombin and partial throinboplastiii times. In the theophylline group one of 65 samples was not obtained and its value was estimated by Yates'…”

Effects of allopurinol on theophylline metabolism and clearance

“…Plasma and urinary theophylline concentrations were estimated by high-pressure liquid chromatography (HPLC). In the case of plasma estimations, a modification of the method of Orcutt et al 15 was used. Theophylline was extracted from 100 ILl of acidified plasma into dichloromethane containing 8-chlorotheophylline as internal standard.…”

Comparative pharmacokinetics of theophylline and aminophylline in man.

“…Serum theophylline was measured by the high pressure liquid chromatographic method of Orcutt, Kozak, Gillman & Cummings (1977) with minor modifications. The absorbance detector (Model 440, Waters Ass.)…”