การวิเคราะห์ยาต้านอาการซึมเศร้ากลุ่มไตรไซคลิกและเมตาบอไลต์ของยาในพลาสมาด้วยวิธีไฮเพอร์ฟอร์แมนซ์ลิควิดโครมาโตรกราฟี โดยเทคนิคการแยกพลาสมาโปรตีน / กิ่งกมล กาญจนาเวส = High-performance liquid chromatographic determination of tricyclic antidepressants and their metabolites in plasma by plasma deproteinizing technique / Kingkamol Karnjanaves
A rapid and highly sensitive reversed-phase high-performance liquid chromatographic method was developed to determine imipramine and its active metabolites, desipramine as well as amitriptyline with nortriptyline, its metabolite in plasma. Acetonitrile and dipotassium hydrogen phosphate solution were used to deproteinize plasma protein prior to HPLC analysis. The mobile phase, consisting of acetonitrile and 70 mM potassium phosphate buffer (40:60 v/v), was delivered at a flow rate of 1.0 ml./min. The effluent was quantitated by UV detection at 251 nm for imipramine and desipramine and at 239 nm for amitriptyline and nortriptyline with the lower limit of quantitation of 40 ng/ml. Meanwhile imipramine and desipramine could also be detected via electrochemical detector at applied voltage of +1.0 volt such that the quantitation limit became 4.0 ng./ml. The accuracy in term of %bias for all four compounds were within -4.34 to 0.06. The relative standard deviation of both intra-day and inter-day precision for imipramine and desipramine were within 6% while that for amitriptyline and nortriptyline were less than 5%. Plasma containing either imipramine with desipramine or amitriptyline and nortriptyline could withstand at room temperature for 12 hours but at -48℃ for 30 days. In addition, plasma could be restored within 3 freeze-thaw cycles. The processed analyte could be withstood at 4℃ in autosampler till 24 hours. This developed method was successfully used for analyzing plasma samples from four healthy Thai male volunteers that administered 50 mg of imipramine or amitriptyline tablet. This confirmed the versatility of the method for pharmacokinetic or bioavailability study as well as therapeutic drug monitoring of tricyclic antidepressants and their metabolites in plasma.
