hi! I am looking for a gc/ms method to detect and monitor oxcarbazepine by gc/ms. In my query through the net I have found several hplc and lc/ms methods. There are references that gc/ms methods exist, however I am unable to bring them up online. Is anyone out there familiar with this drug (an antiepileptic drug)? I would appreciate any/all the assistance out there that is available. Thanks alot...

email{Mschemmie@aol.com,Mschemmie@aol.com}

Is another name for this carbamazepine? There are several references for this e.g.

Determination of carbamazepine and its metabolite carbamazepine-10,11-epoxide in serum with gas-chromatography mass spectrometry
Minkova G, Getova D
METHODS AND FINDINGS IN EXPERIMENTAL AND CLINICAL PHARMACOLOGY
23 (9): 481-485 NOV 2001

Abstract:
Carbamazepine, one of the most often used antiepileptic drugs, undergoes enzyme biotransformation through epoxidation with the formation of its metabolite, carbamazepine-10,11-epoxide (carbamazepine epoxide). The determination of epoxide is clinically significant in therapeutic drug monitoring as it decreases the risk of toxic reactions and increases the possibility of reaching the expected therapeutic result. The aim of this study was to introduce a gas chromatographic method with mass spectrometric detection to simultaneously determine the serum levels of carbamazepine and carbamazepine epoxide. Blood samples from 80 epileptic patients aged between 1 and 63 years' were analyzed. All patients were taking carbamazepine as monotherapy and had achieved the steady state serum drug concentration. A microcolumn extraction of carbamazepine and carbamazepine epoxide was Obtained by elution. A gas chromatograph with a mass spectrometer and a 25 m x 0.2 mm ID, 0.33 mum film thickness, crosslinked 5% capillary column HP-5 was used The coefficients of correlation for the calibration plots obtained for carbamazepine epoxide and carbamazepine were 0.988 and 0.995, respectively. The precision, tested for n = 20, showed coefficients of variation within one day as follows: carbamazepine epoxide: 11.0% and 6.55%; carbamazepine: 11.8%, and 5.4%. The coefficients of variation from day to day were: carbamazepine epoxide.. 9.4% and 6.83%: carbamazepine: 8.5% and 5.7%. The detection limit was 10 mug/l and the recovery 82.5% for carbamazepine epoxide and 92.5% for carbamazepine. A fast and simple gas chromatographic method for the routine therapeutic monitoring of carbamazepine and carbamazepine epoxide was developed The simultaneous determination of the scrum levels of carbamazepine epoxide and carbamazepine offers the possibility of measuring the total drug concentration, as well as that of its metabolite, white considering the results of clinical response and the special features of carbamazepine's enzymatic biotransformation through epoxidation with the formation of its metabolite. (C) 2001 Prous Science All rights reserved.

Regards,
Ralph

Ralph: Thanks for your response. There is a relationship between these two, but I do not believe they are the same thing. Oxcarbazepine is a new drug (Trileptal)and the metabolite appears to be products of 10,11-dihydro-10-oxo-CBZ or I have read 10-hydroxy metabolite. Not sure I'm making sense, but I'm just starting my research on this and even though I find descriptions of GCMS methods available, when i research them they are HPLC methods. Since I don't have a HPLC in my lab, but I do have GCMS we are trying hard to find a reference to monitoring this drug with GCMS. There appears to be immunoassays available also. I will keep looking and appreciate any other information y'all may have to assist me in this hunt. Thanks again..