TLC DETERMINATION OF THEOPHYLLIN IN PLASMA

A procedure is described for determination of theophyllin in plasma by TLC scanner. The sample was extracted with chloroform-isopropyl alcohol (13:2). The extract was then concentrated, separated by TLC, detected by UV and determined by TLC scanner at 274 nm. The relation between the peak area and concentration of theophyllin in plasma was linear from 5～40 μg/ml. The lowest limit of detection was about 0.1 μg. The CV was 6～12%. The recovery of theophyllin in plasma was about 99%. The result was not interfered by some commonly administered drugs. The method well meet the needs of therapeutic drug level moniloring.