Gas chromatographic determination of noxyptyline in substance, tablets and in biological material.

Noxyptyline, i.e. 5-(2-dimethylaminoethyloxyimine)-5H-dibenzo[a,b] cyclohepta-1,4-diene hydrochloride, is an antidepressant. A new, direct method for its determination in substance and in tablets by means of gas chromatography has been developed. The results were compared with those of the spectrophotometric method, and the systematic errors(coefficient of variation) were 2.19% and 2.49%, respectively. Appropriate conditions were developed for the extraction of noxyptyline from plasma and urine, and the gas chromatographic method was applied for its determination. Within the concentration range 0.5-10 microgram/cm3, the systematic error after extraction from plasma was 4.61%, and after extraction from urine it was 2.08%. The recovery from plasma was 71.12 +/- 8%, and from urine it was 90.94 +/- 1.5%.